Adding fins to bottom of flat pan (?)

[StewieSugar]

My 2x4 homemade rig has one large flat pan, and I'm getting about 7 to 8 gph evaporation. I really want to increase my evaporation, but I'm struggling to afford a real flue pan or a commercial evaporator.

In place of getting or making a flue pan, it would be relatively easy/cheap for me to add heat fins to the bottom of the flat pan. For example, my pan right now is 19" deep. I can cut it down to 9" height, and use the cutoff material to make 1" wide by 48" long fins. I'd then weld the fins vertically to the bottom of the pan. The bottom of the pan would then have several (dozen?) of these strips that ran along the length of the pan.

Kind of like electrical transformers use heat fins to remove heat, I'm hoping the added surface area in contact with the flames will increase the heat transfer to the sap - and hopefully improving my efficiency.

Anyone try something like this?

[KenWP]

Problem is you would have all the hot spots running across the bottom of your pan. Would be okay when boiling sap but when you get to the syrup stage you would be in trouble.

[RileySugarbush]

Stewie,

Adding the fins would have a very small effect on the evaporation rate. Especially if your pan is stainless steel. Stainless has relatively poor thermal conductivity, which is why it's important to use very thin sheet in pan construction.

You would be way ahead putting your effort into increasing the area exposed to heat on both the wet and dry sides. That means adding flues. The easiest way to do that is the copper drop tube flues discussed before. Each tube adds about 18 square inches of area!

[KenWP]

If I can find another SS pan this summer I want to try the drop tubes. I can.t find the hammer arrestors here so will have to try tubeing and either close the end off or caps. That for me will be the easiest way to increase the surface area.

[StewieSugar]

Neat idea; never seen/heard of that before.

I see the hammer arrestors at the local hardware store before, but they're a bit pricey. Any concerns with taking standard coppper pipe and soldering on a cap?

Anyone have data on "before" and "after" drop tubes with respect to evaporation rate?

Also, how do you clean those buggers out?

[RileySugarbush]

My first drop tubes used caps. They work fine but are difficult to solder because you have to put the caps on after the tubes are dropped in if you flange the tubes.

Adding the tubes easily tripled the evaporation rate of my steam table pan.

Cleaning is easy: Coat hanger wire, tuft of scotchbrite, cordless drill. Rinse well.


When soldering copper to stainless, use good liquid flux and a very low flame. Tin each side first.

Have fun!

[PerryW]

I have often thought that 1" copper pipes w/end caps would be an easy way to add some poor-man's flues to a pan. It even seemed like you could cut some slots in the top end of the pipes and bend them out flat (horizontal) to create tabs that you could solder to the pan.

It would only work on pans small enough to flip over to drain

[KenWP]

If you use copper tubeing would you use the soft stuff or the hard pipe. I was thinking of useing soft tubeing and then just bend the ends over and hammer flat. Would be quick and sure fire not to leak. Will have to price this out this summer. Now to find the liquid flux. I can find non lead solder paste pretty easy.

[PARKER MAPLE]

My first drop tubes used caps. They work fine but are difficult to solder because you have to put the caps on after the tubes are dropped in if you flange the tubes.

Adding the tubes easily tripled the evaporation rate of my steam table pan.

Cleaning is easy: Coat hanger wire, tuft of scotchbrite, cordless drill. Rinse well.


When soldering copper to stainless, use good liquid flux and a very low flame. Tin each side first.

Have fun!
DO THESE TUBES DROP DOWN ON THE UNDERSIDE OF THE PAN TOWARDS THE FIRE/SMOKE CHAMBER? IF SO IS THERE ANY SPECIAL SOLDER THAT YOU NEED TO ACCOMEDATE THE HEAT?? THANKS I TOO HAVE A FLAT PAN AND WAS THINKING OF INCREASING MY EVAP RATE, THIS SEAMS ALOT EASIER THEN ALLTERNATIVE, CUTTING SLOTS FOR FLUES AND DROPPING THEM IN..

[RileySugarbush]

Ken

I have used water hammer arrestors and copper pipe for water service/caps. Even the hard copper can be squeezed flat and soldered if you want to do that.

Rookie, I used silver solder, but any lead free solder would work. I think the key is to clean the metal well and use good flux and the right flame. Practice!

Yes the tubes drop down into the flue, but the solder doesn't melt because the tubes are full of sap which limits the temp to the boiling point, just like in other soldered pans. Don't run them dry!

[PARKER MAPLE]

ok so if i got this right, i have a 24in pan, i would drill a series of whole front and back run pipe down to the hammer arrestor and a pip to the other end two another arrestor wich then another pipe would complete the run back into the pan at the opposing end.. if this is correct coulde i use 1in pipe and keep them 1in appart?? and how much evap increase do you for see me getting out of a 2ft x 4ft pan with say 20 of these drop tubes??
sounds like an awesome idea..

[KenWP]

Maple Rookie. You drill 1 inch holes in the pan or better yet cut them and flare the top of the water hammer arrestor and drop it thru the hole and solder it in. it is just a tube dropped down the few inches in length of the arrestor. The sap basically boils in the tube faster since it is copper and attacts heat better and drops down so the whole circumference is exposed to the heat. You can also use one inch tubeing and either cap the end after you drop it through the hole in the pan or squeeze the end shut on the tube and solder it and then drop it through the pan. The pictures of the process explain it a lot better.
Another idea brought up was to drop the tubes down through the pan and attach two of them toghether with a short peice of tubeing and elbows. I am thinking you could then run less tubes through the pan and rely on the surface area of the connected tubes to heat the sap. What I also wonder is just how hard the sap boils up out of the tubes and if it splashes a lot. I can see mini geysers all over the pan. Riley might know the answer to that.

[KenWP]

After searching for water hammer arrestors all over I have found they don't sell them up here. The only ones we have here have a piston in them and sell for close to $90 bucks. Will have to use pipe as they don't sell 1 inch tubeing up here either I am told. I have another idea also if I can figure out how to cut 2.5 inch holes.

[Haynes Forest Products]

find a guy that has the hole punch kit that they use to cut into elec panels. The only reason I have one is I found a complete set of them on the side of the road. They will cut/punch a perfict hole every time. Using a hole saw will only get you a sloppy over size hole that will piss you off. The reason that hole saws cut such sloppy holes is the sheet metal cant keep the pilot drill in place because it wallows out as it cuts. There is a trick but its a bitch to do if you drill thru the sheet metal and then into a thick block of steel with the sheet metal clamped onto the block of steel you can get a better hole slow slow slow oil oil oil

[KenWP]

I tried to find a Greenlee punch up here and no dice either. I think they use another name for them up here. Can find them on US web sites. I used them years ago when I did electrical work and the electricians still have them but how the find them beats me.

[RileySugarbush]

Sorry I haven't been paying attention...


Ken has it right regarding the drop tubes. Click on my name and select "visit homepage and you should be able to find a bunch of photos of how I made my drop tube pans.

Any sheet metal shop should have Greenlee punches or equal. Even in Canada.

The sap does jump out of these vigorously!

[SPILEDRIVER]

check mcmasters.com or grainger.com for greenlee punchs.there both maintenance supply com. and i no at one time they both carried them!

[KenWP]

check mcmasters.com or grainger.com for greenlee punchs.there both maintenance supply com. and i no at one time they both carried them!

Thanks Spiledriver. Turns out the other name for them is a knockout punch which is waht they call them up here. I needed another name for them inorder to find them up here.

[johnallin]

I have used "step drill bits" with good results to put darn near perfect holes in sheet metal. Installed a port for a thermometer in my half pint pan with one last year and it worked great.

Just make sure you back the pan up with a piece of wood (2 x 6 or close), keep the pan and the wood clamped together nice and tight and the bit will bite into the pan and the wood without wobbling. With some practice you should have some nice round holes.

Should be able to find one for less than McMaster Carr prices but here is link

http://www.mcmaster.com/#step-drill-bits/=22ky8e

[KenWP]

I have the step drills already and if I could not rent a knockout punch would have resorted to useing it instead. The best place to buy stuff like the knockout punchs closed May 13 up here and I haven't found another outlet for them yet. I can also use a 1 inch drill bit if I use wood or two peices of steel with 1 inch holes drilled in them as guides.

[KenWP]

A fellow at a garage sale gave me another SS sink this weekend so I am half way towards my new pans now. I just have to get one more then figure out the drop tubes for at least one of them and I am away. I have a couple of ideas on them. One is to make only 6 drop tubes but to connect two together underneath with a cross tube so as to increase the surface area. Also for the drain hole I want to solder in a SS cup into the hole to increase the surface area. Will see how it goes if I can find one more sink as those resturant pans are non exsisitent around these parts except the shallow ones.

[3rdgen.maple]

Hey ken with the amount of taps you kept adding this past season get yourself a 2x6. I can just imagine how many you are gonna add next year. It all starts with 30 then 150 then 300 and like the energizer bunny it keeps going and going and going.:mrgreen:

[KenWP]

Riley what size Greenlee punch did you use. The copper pipe measures 1 and 1/8 inch around here. I almost bought a 1 inch punch off Ebay untill I stopped by the Quincaillerie and measured the copper pipe and found out how much over a inch it was.

[Gary R]

Ken,

I'm with 3rdgen. The amount of taps your talk'in about might require more than steam table pans. You can make a drop tube out of a flat pan. You add stainless tubes horizontaly through the pan. All flame and gases go through this. Lots of boiling capacity. I think WF Mason makes these.

[KenWP]

I have no idea where a person could buy SS tubeing let alone anything else SS. I finally found a guy who could tell me where to even buy steel around here. I am basically trying to get by with what I can find around here. I grew up in the oilfeilds and metal and all that good stuff was all around me but in this part of the country the selection just dosn't exist.

[3rdgen.maple]

Ken do you have any scrap yards around you, if they exist there check with the transfer stations (local garbage dump) The usually have a metal recycling area where people drop off there junk to them metal. There are a million websites to get metal from also. Guess everything depends on the ole budget. Keep looking you will find the mother load and then the boss of the house will be mad cause of all the goodies filling up the garage.

[KenWP]

Well found another SS sink today so I can start on my updates. I still have to figure out how to cut the holes in the metal but if all else fails will drill them out and then ream to the right size afterward. I know you guys figure I am nuts but my Grandparents came from Penn and Iowa so that expalins it pretty easy I hope.
Now to find thin wall copper tubeing.

[RileySugarbush]

I recall it being one inch even. Certainly it was a free but close fit around the OD. I then flared the copper 90 degrees for the solder joint.

[KenWP]

There is chance the arrestors are 1 inch even but the tubeing is 1 and 1/8 od. I will figure it out. I even found a chunk of aluminium today to make the die for flareing them.

[3rdgen.maple]

Just a dumb question here but why does it have to be an inch. Would it not be easier instead of searching all over maple country to find the copper pipe you are looking for and just go to the hardware store and by what size they have on the shelf. 1/2 inch ,3/4. I know you are thinking surface area but smaller pipe means more holes which means surface area. Get a 10 foot section of copper waterline and some caps. Cut, flare the top, drop in hole solder cap on and solder to the pan. Thin wall, thick wall whatever copper transfers heat very well and either one is gonna increase your evap rate. Ken I don't think you are stupid be proud man and do what you are capable of and enjoy the hell out of it.

[RickinFarmington]

Ken you have inspired me to upgrade my back SS sink pan as you are doing. My pan is 15x 21 and is now marked with 15 one inch circles which I will start to punch out with a Greenlee punch, flare, and soldere in place.
Made a test piece with a scrap piece of SS and it went quite easy. The key to easy soldering is in the proper flux, which needs to be acid based.
I am making my drop tubes 3 inches long which will add about 9 square inches of surface area each, or 135 added to the 325 inches of the flat pan. I suspect it should really give my rear pan a real shot in the arm.
The only concern I have at this time is, what effect of it may have on the pan in terms of warping when I put the fire to it.

Rick

[KenWP]

Already thought to go to 3/4 as that,s easy to come by in the hardware in town and I have the tools already to drill holes that size. The 1 inch is a problem to find here for some reason. I am thinking to much on heating up a 3/4 inch tube might cause the sap to spout up to much.

[RileySugarbush]

Ken,

I found a left over scrap and my copper tubes were about 1.125 OD, like yours.

3rdgen,

No reason to avoid other sizes. Rather than caps, if i was doing this again I would flare one end, solder in place, pinch and solder the bottoms. Cheaper than caps.

Rick,

I'd make them longer if you can. Mine were 6 or 7 inches deep and worked great. Liquid acid flux, clean surfaces, low heat and tinning both surfaces firs made soldering (almost) easy. The bottom of the pan remains unwarped.

I'm looking forward to seeing how you guys like the flue tubes. I sure did!

[MartinP]

I am thinking of adding a manifold to the bottom of the drop tubes by using Tees with elbows on the first and last in each row. Using 1" copper, 3" Drops. Does anyone know if by adding manifold to the drops will the sap make geysers at each hole opening?

[MartinP]

I was thinking of Drop Tubes with a manifold connecting all the drops. Now rethinking maybe 2" Copper thru the pan end to end 1/2" off bottom. Re thinking because Tees are 8 bucks a piece and 10 holes to solder are easier than 50. 2" Copper is 145.00 per 10' Length
2 lengths will give 5 thru tubes in 4' flat pan. 5 Tubes will add 1508 Sq" of area to pan. Current pan size is 28" x 48" (1344 Sq"). If I calculate right that should give 112% better boil rate. Has anyone ever tried thru flues? Basically the way I am thinking is that they are just like drop flues but are attached on the end of the pan and flue gas is directed into them and out the back of the pan as well as going under pan. Any ideas will be appreciated as I would like to get started soon.

Martin
1st yr 5 taps 2 steam table pans
2nd yr 20 taps 4 steam table pans
3rd yr ?? Maybe 50

[Dennis H.]

Here is a cool drop tube evap from along time ago I found it by doing a search for patents at Google Patent.

It is kind of cool that it uses the tubes as the grates.

[KenWP]

That's sort of how a old coal frired boiler worked. Was made of hollow plates in a square and the coal burned in the middle. I took many of them apart out of old CPR train stations .

[Haynes Forest Products]

I wonder how well new sap would replace the soon to be syrup. I think the tubes could vapor lock and you would get scorching.

[Gary R]

MartinP,

Drop tube evaporators are made commercialy the way you are thinking (horizontal). I believe WF Mason makes them. I know a guy who has one and loves it. It might be had to find, but price out a 20' length of stainless. I bet it would be cheaper than copper. You would need a plasma cutter to cut, but it would be easier to clean.

[KenWP]

Makng tubes connected on the ends was my dea also as it would requre less holes to solder up. I would lke to use SS tubeng but who knows where to get it around here also. I used to use it in half inch water pipe for years but its expensive.

[birdmancf]

Dennis, thanks for that, it was a fun read to see someone else whose taken their thoughts to the limit. I wonder it he ever manufactured them. Now I'll have to try to add the element of angled pipes under the pan to promote better flow(especially when pouring) and lack of vapor lock.

Can't wait to hear and see from the first of the group who gets their copper pipes installed. I couldn't find any hammer bodies that would be worth the cost and effort. Now planning on angled pipes under the restaurant type sap pan.

[KenWP]

I am trying to figure out how you plan on attaching these tubes. With the drop tubes at least they would be flared and dropped in from the top and soldered in. With tubes attached from both ends only one end could be soldered. Thats why I thought that dropping 3 inch tubes down and attachng two toghether with a cross peice would make sense as it would make for less holes to solder and still give a good surface area to the flame. I am also tryng to figure out how to cut 2.5 inch holes and solder SS tubes made out of SS cups I found into the pan. One of many ideas floatng thru my head.

[RickinFarmington]

OK guys, I have 15 each, 6 inch long, 1 one inch copper tubes, cut, flared, and ready to drop in and solder. Have the all the caps as well.

Now, I am getting nervous about what I am about to do. Need to hear from anyone who has actually constructed this style of pan with a report of the pros and cons.

Will I be making syrup in the tubes or will the raw sap cooler sap find its way down into the tubes??

I remember seeing a picture of a SS sink pan modified with drop tubes on this site, but do not recall a report as to how well it worked.

Rick

[MartinP]

To use the thru tubes you would make each half the length that you need, Flare one end of each half, solder one tube in pan, put coupler, on slide other end in solder then solder coupler. At least that is the way I plan on doing it. And the cool part, if you want to add even more area you can put drop tubes below the thru tubes in the bottom of the pan.

[birdmancf]

Oh, okay....someone just had to go and suggest it, now the ideas of drop tubes off the thru tubes is rumbling through my brain. Can't wait to design that on Google sketch-up.
Wait...take a breathe, drink some coffee. There I'm back. I just have to remember to Keep It Simple Stupid!:lol:

[KenWP]

OK guys, I have 15 each, 6 inch long, 1 one inch copper tubes, cut, flared, and ready to drop in and solder. Have the all the caps as well.

Now, I am getting nervous about what I am about to do. Need to hear from anyone who has actually constructed this style of pan with a report of the pros and cons.

Will I be making syrup in the tubes or will the raw sap cooler sap find its way down into the tubes??

I remember seeing a picture of a SS sink pan modified with drop tubes on this site, but do not recall a report as to how well it worked.

Rick
As far as makeing syrup in the tubes it wll be like a regular drop flue pan the water will go to the bottom of the tubes. If you read the link to Rileys way of makeng the pan it descripes how to attach the tubes. You need to tin around the hole first before droppng the tubes in and then solder them in that way you have a better attachment. Of course there is cons to everything but lots of plus's. Reports are that if done right t can triple boiling rate.

[RickinFarmington]

OK, I am convinced. I did a test piece this morning and the tube soldered up easily. Beat on it and it is strong.
Plan to do one hole at a time, as not to distort the pan bottom. This thing ought to be quite a sight when completed. Will post some pics when I finish.

Rick

[KenWP]

It's relatetivly simple to do once a person gets started on the project. What did you cut the holes with. I need to be able to cut 1.125 inch holes to do this . I have a few months to figure it out still. For the big hole in the middle I have some a SS cup I am going to solder in for extra surface area. I am slowely gathering metal to build this contrapton.

[RileySugarbush]

Don't fear guys. These are pretty easy to build and I don't think you will be disappointed in how well they work. Just like a flue pan, you can't finnish syrup in it. But it really works well as a sap pan.

[RickinFarmington]

John great picture of the finished product. Can hardly wait to get my pan completed and test fire it.

ANy tips for cleaning the pan bottom after use?

[RileySugarbush]

I didn't worry much about the outside. A pressure washer gets most off. Inside I used diluted muriatic acid and a cordless drill with a wooden dowel and scotchbrite. Shines it right up!

[KenWP]

Today I found out I can rent a set of Greenlee punchs so when I get everything figured out I can rent the tool. Its hydraulic so it won't take long to punch the holes out when I decide what I am going to use to do it. I also found thin wall 1 inch copper pipe today. I have months to get it ready for next spring so will work on it this fall or winter when I am bored.

[3rdgen.maple]

Ken I would consider not waiting till the winter to do your handy work on that pan. If things go wrong your out of time.

[KenWP]

There's that also. I am at least thinking about it. When I get working on it then it usually goes pretty fast as I have it all thought out as what will work best for me. or untill some genius comes up with a new plan that I try and copy.

[BarrelBoiler]

building one of these seems like a good way to fill the space at the back of the proposed oil tank rig i want to build

question.... why don't you make syrup in the bottom of the drops???

thanks

[RileySugarbush]

When you pour the heat on there is nothing holding still in those flues! It'sall well mixed by the boiling. As long as the average in the pan is not syrup, it's not going to turn into syrup in the flues. Just keep a smaller pan to move it to for finishing.

[maplesyrupstove]

tube pan evaporator ,not sure where it was. Just found the pictures,looking for 3 weeks.

[KenWP]

That would boil sap for sure. All the heat has to pass by the sap before it can go out the chimney. Is that a WF Mason product. I did find SS tubeing today as I was driveing around I found a new and used metal shop and went in and asked him what he had. He had lots of good stuff in there and seemed like a guy who didn't mind being asked a lot of guestions.

[MartinP]

The picture is kind of like we are makeing except that we only have one row of tubes going thru pan. Planned on still having flue gas go under pan as that adds surface area.

[Dennis H.]

That looks like a steam loco boiler, but with a lot less tubes.

May make it a little tough to clean the bottom of the pan at the end of the season, but you are right that would have a lot of surface area.

[KenWP]

Just dump some acid into it and heat it up and it should clean up pretty good. It you could make the holes for the front and back plate at the same time so they line up it would be semi okay to build. The plates could be thicker steel to make it a bit easyier to weld up.

[KenWP]

Okay I need a name or something of a flux for SS and not useing lead solder. I can find no lead flux but not for SS. I found flux for SS but it dosn't say anything about non lead on the bottle.
Also is the solder for SS to SS the same as copper to SS. I might have to test out a peice before trying it on the real macoy.

[MartinP]

I found that the liquid flux works better than the paste. The SS solder sticks the copper so well that you can bend the SS with it. Make sure to tin both the copper and the SS before soldering. Keep the heat low.

[KenWP]

Found one type of flux named Kester that might work. It's liquid and cheap so trying it out wont break the bank. Bought a couple of the brushes to apply it with and will try this on a peice of scrape before I invest time in the real thing.

[Haynes Forest Products]

OK dont get mad but here I go........... If the flux your using will CLEAN the metal and allow the solder to stick to it........and you have two differant type of metals and the solder sticks to both of them and its the same type of solder what is the problem? Your really not attaching the two metals your joining the solder that is stuck to the metals. Think of the solder as the primer between the paint and the metal. Is the paint sticking to the metal or the primer? If your afraid that the metals wont like each other dont tell them let the solder worry about it. I used to solder gold to SS with a silver based solder its all about the solder being compatable with both metals. The trick is as stated by others is to tin both peices before you join them together. Then you only need to heat both items until the solder melts joining the items together. MartinP said it keep the heat low and slow. Over heating will cause the metal with the lower melting point to oxidize and at that point the solder will ball up and lose bond and your screwd.

[KenWP]

The tinning both parts and then attaching makes sense. Sort of like contact cement. Guy just has to try it himself and see what happens.
I am going to try thin SS pipe as it was a lot cheaper to buy then copper pipe and see what happens.
I just have to buy a tubeing cutter instead of trying to cut it with hacksaw or skill saw.

[MartinP]

We started soldering up the thru flue pan today. Got 2" Copper cut and flared. All the holes and flares tinned, ready to go. Ran out of solder. Still have to solder the flares to the pan ends and 2 more couplings in the middle. Hopefully we will get it finished Sunday. Will post pics when done.

[MartinP]

The Thru pan is finally done. Now on to building an arch to fit.

[MartinP]

Pictures didn't attach with the last post.

[KenWP]

Took me a minute to figure out what i was looking at. Makes sense once I figured I was looking at the top of the pan. Should work as a flue pan. We need reports on how well it boils when it gets going.
I am working on the drop tubes for mine today fianlly 3rdgen has me fired up to get it built before next spring. I am useing SS tube as it was cheaper but it is a bit harder to work with when it comes to cutting and also flareing the ends. I think my cap system for the bottom should work out okay. If not back to the drawing board. Found out a freind of mine is a sort of retired electrician and hes has several sets of Greenlee Punchs that I can borrow so I am set to get things rolling now.

[3rdgen.maple]

Martin, how far down in the arch does that pan sit. Looks like if it sits on the arch rails the syrup pan would block off the hot gases from entering the tubes. I would get that pan down in the arch if you already have not thought that one out. Nice job too it looks great. Test boil that baby and let us know how she works.

Ken, Go get that pan done. I think you made the wise choice starting her now. You just never know. I want to see pictures when it is done. All these post you got out on this one we need to see that craftmanship. Good luck.

[KenWP]

Got the tubes cut and flared today. Took a bit of doing to figure out how to flare them but found out they fit inside a peice of iron pipe so I cut it 5 3/4 inchs and the drop tubes 6 inchs and then used that to bend over the flare. Worked well once I figure out how to do it. The cap on the bottom is a bit harder to make but I have 3 made already.

[MartinP]

I do not have the arch built yet. I plan on using block to start. The pan will fit inside the block and then rest on brick inside. That should shield the pan sides from cold and help boil better. It will be lower than the front pan and will sit so that the bottom of the front pan sits just above the thru holes in the back. I know it won't drain completely but it only needs emptying at end of season. It will be a couple weeks before I get anything more done. We are making another pan like it for a friend but 2' long instead of 4. The arch will be experimental so that pans can be moved up and down and the slope inside the arch can be changed to determine best positions for boil. The final arch will be made from steel.

[KenWP]

Found out today that they actually make cut off disks for SS. The ones I was useing were burning up to quick and the one I bought today lasted for the whole time I was cutting. I should have checked weeks ago and not frustrated myself so bad. Am actually getting soemthing done now instead of looking at peices of steel and saying man i wish I could cut that faster somehow.
I now have to solder in my tubes and see if it hold water.

[KenWP]

I must be doing something wrong. I can't get the solder to lay flat all it does is ball up on me. I could be useing the wrong flux or the solder could be wrong also. I am useing the silver solder and the flux is called Kester and says its for SS. Can't find flux that says SS and lead free on the same label. I tried tinning a hole in the pan and it also balled up on me. Any help would be appreciaited.

[StewieSugar]

Brazing requires a lot of heat. - not just to the solder but to the metal as well. I suggest you try applying more heat directly to the stainless steel pan (and not to the solder or copper). The pan will act as a huge heat sink and rob all the heat away - you'll need a good size/hot torch to get the local temps high enough for the solder to start sticking.

[BarrelBoiler]

i'm not a profience nor professoinal solder-er (if there is such a word) there are a few things i have noticed about people who do it alot.with copper water pipes they clean-flux-assemble-heat the joint-apply solder usually without anyflame and they are done.

never having done any SS i'm not sure, it sounds like not clean enough or not hot enough and the solder is melting in the heat of the flame instead of from the heat of the metal

i'd try cleaning ,fluxing where you want to tin and heating from underneath whne the flux starts to react to the heat try your solder, if it doesn't melt take it off and keep heating alittle more and try again. with a big heat sink like a pan it will take some time to get the area hot enough to melt the solder

patience and pratice in some scrap good luck
again i am NO expert this would be my next plpan of attack

[PARKER MAPLE]

Pictures didn't attach with the last post.

martinp, i just bought a second hand drop flue tube pan kind of like yours. it was actually made by leader for a few years. the only thing that i can see that different is i have two big 7in drop flues that are shapped in a v. these house about 10 of these tubes appeace, so 20 tubes altogether. the person i bought it off of said it boils awesome as he had made about 700 gal of finish product, with his ro machine of coarse.. but take this as some incentive, and we can only hope they work half as good as he says. nice work maple rookie

[Fred Henderson]

I must be doing something wrong. I can't get the solder to lay flat all it does is ball up on me. I could be useing the wrong flux or the solder could be wrong also. I am useing the silver solder and the flux is called Kester and says its for SS. Can't find flux that says SS and lead free on the same label. I tried tinning a hole in the pan and it also balled up on me. Any help would be appreciaited.

I have soldered SS with and iron and a torch. If you are going to use a torch, it must be very hot and a fine point. Get it hot then apply solder, if it flows out good its hot enough, if not more heat is needed. In most torch cases I have used oxy& acct.

[KenWP]

I never realized that SS could have a film on it also. I hadn't really cleaned it well enough before I fluxed it. I will try again tomorrow with a cleaner surface. I read over the link Hanyes told me to search and it had better directions on how to solder SS. Guess there is clean and then clean. The solder I have and the flux is correct according to the web site.

[Grade "A"]

I never realized that SS could have a film on it also. I hadn't really cleaned it well enough before I fluxed it. I will try again tomorrow with a cleaner surface. I read over the link Hanyes told me to search and it had better directions on how to solder SS. Guess there is clean and then clean. The solder I have and the flux is correct according to the web site.

Ken, when you are heating the ss is when the film can form. I use Harris Stay-clean for stainless (it is a liquid acid flux), if the solder will not stick to the stainless add a drop or two when it is still hot and the solder should then bond to the steel. Don't breath the smoke from the flux because it is an acid.

[PARKER MAPLE]

How Are You Guys Resizing Your Pictures To Attach Them On Here??

[PARKER MAPLE]

How Are You Guys Resizing Your Pictures To Attach Them On Here??

CHECK OUT MY FLUE PAN IN MY PROFILES PAGE AND LET ME KNOW WHAT YOU THINK..

[MartinP]

We just got back from the Sugar Bush, Started the new block arch this weekend.
Here are pictues of the new arch with the pans installed. The pic on the right is thru the fire box looking at the bottom of the pans
Maple Rookie that is a nice looking pan, you should do well with it.

[Gary R]

Nice looking pans guys. If I made another one I think it would be a drop tube flue pan.

Maple Rookie, you need to use some type of picture editing software. There are many types out there. I am using Microsoft Office picture manager. When you post a reply, scoll down the page. You will see box for manage attachments. Click on it. You will see the size of the files the site will accept. By clicking browse you can search your computer for the compressed picture. Click on the picture and hit upload. After loaded, close window and sumit.

Hope this helps.

[KenWP]

I got a little better at solder today. I found I have to buff the SS flux and then heat it and then use a wire brush on it and then flux again and then the solder will stick most of the time. I will be a while getting this done it looks like. I had only soldered copper before and this is way harder to do. When I am done it better work or else.

[RileySugarbush]

Ken,

You are doing this in the right order. Clean stainless is the ticket. I sanded it, then flux, then solder. I found that using a propane torch with Sta Brite flux and silver solder worked great. I used a very low flame, otherwise the heat would boil off the flux on the far side of the hole and I would need to re clean and flux. Once you get the touch it works great.

[PARKER MAPLE]

CHECK OUT MY FLUE PAN IN MY PROFILES PAGE AND LET ME KNOW WHAT YOU THINK..

ok guys i finally got it i think let me know what you think,

[PARKER MAPLE]

ok guys i finally got it i think let me know what you think,
as you can see its all copper, and the tubes them selves are about 1-1/4 id and run from front to back, the flues are a total of 7in deep. there is a 2in tube that runs over the flue tubes, this comes off my float box. its a preety simple set up. what im think about know is, i could make one of these out of my 2x4 flat pan just by adding the tubes.

[KenWP]

Ken,

You are doing this in the right order. Clean stainless is the ticket. I sanded it, then flux, then solder. I found that using a propane torch with Sta Brite flux and silver solder worked great. I used a very low flame, otherwise the heat would boil off the flux on the far side of the hole and I would need to re clean and flux. Once you get the touch it works great.

One thing I wasn't doing right was sanding it. I guess when I do copper I allwasy use emery cloth to clean it and I found it works on the SS as well now that I do it. Live and learn. I have also to plug the holes in the sinks found SS containers that fit so I have a increase in surface area for there also.

[MartinP]

Well, got the Smoke stack and the draw offs done on the pans. Heading to the bush this weekend for a test fire on the thru thru tube pans. If all goes well should see a significant improvement over the 4 steam table pans on propane from last year. New rig is 28" x 24" front pan, with 28" x 48" back pan with thru tubes, on wood fired block arch. So far this has been fun project. All told, have only $400 into it so far. Most expense was for the stack, as I had it made. . I will post results upon return home Sunday night. If the weather holds off might get a start on Sugar shack. Plan on 12' x 16'. Does anyone know what size cupula I will need to let out the steam?

[StewieSugar]

Does anyone know what size cupula I will need to let out the steam?

Elsewhere in these forums, folks seem to be relatively consistent in saying the cupola should be the same size as your evaporator. That is, 28" by 72" your case.

[vermaple]

Does anyone know what size cupula I will need to let out the steam?

Use a roof opening equal to the pan area of your evaporator if you are using open pans. To much opening is no problem, so if you think that you may expand make the cupola larger at this time. Also if you have a preheater or a steamaway you can go with a smaller cupola.

[Jim Schumacher]

Interesting idea.

[lpakiz]

Very interesting Jim,
Could you give us the dimensins of those fins??

[Jim Schumacher]

Www.smokylakemaple.com

[MartinP]

This weekends test boil went pretty well, Front pan boiled hard at 50 minutes, back pan took exactly 1 hour for the front of the pan to start up, got hard boil the fron 1/3 then meduim next 1/3 then lazy boil the last 1/3. Started with 10 gal in front pan and 35 in back. I forgot to get a hose to connect the 2 pans so I did not get to run a tru test as I was mainly concerned with back pan and how it worked. It rained pretty much all day so I didn't get started until 6 pm and shut her down at 9. Estimate 12-15 gph now. I need to change the area under the pan and make it slope more to the back and end up at around 3/4 to 1". Right now its at 1 1/2 flat all the way. Also need to build some sort of real door to feed wood thru. Patio blocks work but not great. Another lengnth of stove pipe to help the draw also. The thru tubes looked rea; nice thru the feed opening you could see flames going down them, so at least I know they do work.

It has been suggested that I start a new thread and go thru the process of this project. Have you guys had enough of me or do you think it is appropiate?

[SPILEDRIVER]

oh man just when i thought i was about done building my new evap you gotta go and say something to make me start to think about trying some fins on the bottom of my new flat pan!!!!!!!!!i guess it never ends!!!!!!!!:o :o :o

[KenWP]

It allways happens that way you have a good idea and somebody comes up with ten more. No wonder sugar makers drink beer. I have to get working on mine pretty soon but with all the meetings this week I am in no mood to think right now. Goverment can make a guy lazy.

[Gary R]

Jim,

That sounds very interesting. I take it the welds go the full length of the fins? I have always noticed on my 3 section flat pan, that it always boils hardest next to the dividers and there on the top side of the pan. I guess we should look at it as a bunch of 1000-1500 degree pieces of metal on the bottom of the pan. That heat has to transfer somewhere. Now I need to decide if I'm going to do a bunch of welding on my pan:rolleyes: Thanks so much for the idea and feedback.

Martin,

I think those drop tubes are set up so that all the flue gases go through the tubes?

[MartinP]

Gary,
The tubes are set in the boiling part of the pan and go the length of the pan and exit out the back. Flue gas goes thru the tubes and under the pan. The idea was to increase surface area. It looked to be working when you looked thru the fire box, you could see flames going down the tubes. I took pictures this weekend but for some reason the card from the camera now says it is not formatted. I am going north again this next weekend and will try another test boil and pics. I think I need less space at the back of the pan to concentrate the heat. Will try adding another length of stove pipe to the stack and see if it draws harder also. The back pan sits about 3 inches lower than the front and the draw off to the front pan comes off above the tubes to keep them covered. That leaves aprox 30 gals in the back pna at all times to keep the solder from letting loose on the tubes. It looks funny but it should work.

[KenWP]

With that pan Martin you could have the bottom of the flue almost touching the bottom od the pan. A half inch of space would maybe work. If you do the math figure out the surface area of each tube at the end and then the space at the bottom would be the difference compared to the stack. It's hard to explain typeing. Air will take the easyist path so the more you force the air down the tubes the better as long as you do not restrict the air flow also.

[Jim Schumacher]

Www.smokylakemaple.com

[MartinP]

KenWP,
There are 5 2" thru tubes, 6.283" each, 31.45" of opening for all 5. The pan has 24" of space between the brick it sits on. 24" x 1/2" = 12. 12 + 31.45 = 33.45 Sq in. I have an 8" stack, 25.132 sq in. Does this mean I need a bigger stack? Looks like at 1/2 in cunder pan I come up 6.318 in short. If that is the case I wasted 200 bucks on the stack. It is 31 1/2 wide 7 1/2 deep and 36" tall all tapering to the 8" round opening at the top.

[Gary R]

Martin,

Area is Pi x R2. Your 8" pipe has just over 50 sq. in. Your pipes only have about 16 sq. in. I would guess your not getting your heat out of the fire box and in the flue. Try reduce to 6" pipe and a blower maybe.

[MartinP]

Gary,
Do you think I could damper the 8" pipe to slow things down and keep the heat upder the pan and in the tubes longer? or will it just make a lot of smoke.

[KenWP]

You can damper it to try and see if it helps and when you want to shut down a damper helps. You already have the space under the pan cut down to a half inch so you just need to have the draft straong enough so that enough heat passes thru the pipes and under the pan for it to heat up fast enough.
Like Gary said a small blower would help a bit plus your stack has to be over twice as long as your arch.

[MartinP]

KenWP/Gary,
I think KenWP may have just hit on the problem. Currently I only have 8' of stack. I will put on another 5 feet this weekend and lower the pan. Also add a damper and get a reducer to 6" stove pipe. If I put the reducer on the top of the stack it should have the same effect as using 6" pipe and it will be easy to test. The arch is not air tight yet so I think a blower will cause issues at this time. I paln on doing over air blower once all the kinks get worked out. I think I will also raise the fire box floor to get the flames up to the bottom of the front pan more. Currently I have no grate under, just some brick on thier sides to hold off the floor.
Once everything works as expected I plan on putting refactory cement over the brick in the fire box, sealing it up. Hopefully I can get a loading door built yet this week. Currently the door is 16" X 16" and I put a couple of patio blocks in front to control draft. There are 2 cement blocks laing on side with the cores going thru to let air in the box.
I really appreciate all the advice, this wood fired experiment is way different than my propane fired steam table pan cooker.

[Gary R]

I dont think the damper or reducer on top will help. The added length will definately help. It seems you need to draw the heat out of the fire box. More stack will do that. I had a similar issue last month during my test fire. I reduced the flue area to less than 30 sq. in. I have an 8" stack. I could not get the back of the pan to boil. I removed some blanket from under the pan and all was well. You will probably have to try different combinations to find what works. Seems these rigs all work best a little different. Be glad your doing this now and not in Feburary right before the season.

[MartinP]

Gary,
So if I lower pan to 1/2" that will give me 12 sq" and the tubes are 16, total is 28" that will be under what you recommend. You say you removed blanket from under pan on yours, How much space is under your back pan?? It does not look like I will get the door done this week, but at least I can close up the opening with blocks. Will adding 10' of stack(total 18) be too much? or does it hurt to be to tall?
Thanks,

[Thompson's Tree Farm]

The taller the stack, the more draft you will have.

[Gary R]

I now have about 2" of space under my pan. It is about equal to my stack area. I am no expert on this stuff. I think you will have to use trail and error because every homemade arch is different. If you know anyone that has a WF Mason drop tube, check it out. I know a guy who has one. He is very happy with it. I just have not looked at the arch to see how it is set up. Another thing to remember, you are trying to bring 40(?) gal. to a boil. Regular 2X4 flat pan may only have 7 gal. depending on depth. BIG difference.

[KenWP]

thats one of the differences trying to boil 40 gallons of sap is a lot of sap in a small area. You have to make sure you have a good preheater also so that it allways boils. If you actually can get a rolling boil on it your way ahead of the game because then you can dribble it into the front pan and finish evaporating it there and once you get the front pan to syrup you can remove it a little at a time and filter and finish it in one big batch on another heat source.

[MartinP]

Thanks guys,
Maybe the thing is good already with extra stack it may just work as expected. The front was hard boil last weekend and it just kept going down to the back where it was just bubbles coming from the tubes , what I called lazy boil. I think I will still raise the bed a bit and add the extra stack and see what happens. I have 5 more feet of stack now, will pick up another section for the weekend, should have 18 feet then. With the addition of blower it should boil hard all the way to the back. I reformatted the camera card so maybe I'll have pics for next week.
Thanks for all the advice.

[3rdgen.maple]

Martin stack height is the key. I dont want to throw a wrench into your guys test boils and fun you are all having but remember guys those things are not gonna boil the same as they are in the spring. Different weather different barometric pressures. Ever watch an evaporator boil like mad then an hour later you are doing everything you can to keep a semi good boil going. Not to mention sap boils different than water. You guys just might find out those rigs boil so hard you cannot stop the sap from jumping out the pans. You might be getting 100 gallons an hour but only actually keeping one gallon in the pans.:D

[MartinP]

Well I got the 2nd test done this weekend. I added stack to the unit and got down to an inch under the back pan. I got 13 gph from the back pan and 5 in front. With the weather being heavy I think it effected boil alot. 1st pic is at the back of the pan without the Stack installed. 2nd is the rig, 3rd is the thru tube back pan. I don't think the sap is going to hop out of the pans, they are both 12" tall, but we can only hope we get close.
I will leave it alone for now and start the Shack.
Thanks for all the advice,

[KenWP]

Thats 18 gallons a hour which isn't bad at alll compared to 3 gallons a hour. I used to boil from 7;30 untill midnight or later to make a gallon of syrup or a bit more if the sugar was higher. I am hopeing to cut that by 2/3 hopefully if I ever get things put together. Run into a snag getting the holes made in the pans. Found you can not depend on so called freinds for help around here.

[3rdgen.maple]

Martin I have well over 12 inch sides on my drop flue pan I run it at about an inch over the flues and darn if sap does not jump out the pans. I gotta measure but I think they are 17 inches tall. Good job man.

[StewieSugar]

I got 13 gph from the back pan and 5 in front.

I'm trying to see how much improvement in evap rate I might get, but I'd like to scale it by the size of the pans relative to your pans.

I looked through the thread put could not find the size of your pans. Do you have the dimensions for both front and back pans?

Thanks

[MartinP]

28" x 24" Front, 28" x 48" Back. Both are 24" exposed to fire box/flue area.
Martin

[3rdgen.maple]

Martin I did not realize the size of your pans. How many taps you plan on this coming season? 18gph sounds good with a water test I bet you will see 20 plus in the spring. I gotta say the bad part about owning a manufactured evaporator is you can't play and have some fun with it in the off season. I miss those days. That flue pan you built looks good.

[MartinP]

Ok guys,
Thanks for all the help and PM s about this project.
Here is how the pans came about, A friend and I wanted to build/buy something that would work better than the steam table pans we have been using, because boiling sap for 20+ hours on the weekends just doesn't make sense. I have been boiling on 4 steam table pans with a home made rig including burners and last year it was costing over$ 60 bucks a weekend for propane. Step one wood fired. Decided on a 6' rig. I checked into buying pans and they were just to much to justify when you just give the sweet away. Second, build pans from SS. Sheet stainless = big bucks, I was checking auction sites and found a 22' x 4' x 4' comercial range hood. Food grade SS. At last now we have SS to make pans. Cost $180 ( $90 my half) , enough material to make 2 complete units with still over half the material left for making accessories or extra pans. After picking up the hood and spending a weekend laying out the cuts, taking into consideration the tracks for mounting the filters and the fire supression stuff, decided that pans would be 28" wide by 2' , and 28"w x 4' long. Bought 4 metal cutting blades for circular saw, Cost 5 bucks each, $20 bucks. Cut and welded up the 24"x 28" pan first. Welding went good only one leak that was easily rewelded up. Next the big pan, got it cut up and welded, 1st try no leaks. Next thought, need more surface area to make xtra boil, reading on flue pans came up with the idea for Thru tubes. Then started reading on this site about drop tubes. Thats when I thought for sure the thru tubes would work. Trip to Box store. Two 10' lengths 2" thin walled copper tubeing, and 5 couplings, $96. Cut them up into 10 24" lengths. Friend has metal lathe and a piece of 2 1/2" round aluminum stock. Bored a hole to fit copper pipe thru then cut slots in it on the back half end so we could clamp to copper pipe.. Layed out and drilled the holes through each end of the big pan to accept the pipes. Stick a pipe through the hole and clamp jig to it on the inside of pan, left about 1/4" of pipe sticking out end of pan. Hammered the part sticking out until it was flared flat on the pan. Did that on all 10 pipes, flaring each into the hole they would go in. Stick the coupling in between 2 sections of pipe inside the pan and soldered it up. Found out that liquid flux works the best. Then soldered the flared ends to the pan. All Silver solder. Built the arch using cement blocks (new) $50 and bricks for the fire box that were left from remodling house when the fireplace was removed 15+ years ago. Wife is sad to see the stack of them go. Drew up the design for the stack, after building the arch, and had a local Heating and Cooling place make it up. $205. Now I want to make pan rails instead of just sitting pans on brick. Might just try to incorporate air over fire into the front rails. The testing parts are posted earlier in this thread. My rig is basically the test, we are soon starting the 2nd unit that will consist of two 2' x 28" pans, one being thru tube. Will keep everyone posted as progress continues.
Sorry for how long this is,

[KenWP]

Tired me out reading it let alone doing the work. I bought SS 1inch tubeing instead of copper to make my drop tubes due to the price. But sure takes time to flare the ends. I cut disks from 1 1/8 SS shaft to plug the ends and then pounded them in to the tube and staked with copper around the sides. I had a so called freind from Lodge offered me a knock out punch to use but he never came up with it so I am going to have to rent one I guess. Just a pain to have to drive that far both ways twice to rent one at the moment.
I had to learn to solder as I never thought of haveing to rough up the edges the first go around and all the silver solder dropped off. A light roughing up with emery cloth and the solder sticks now. DUH. Now just to get the holes drilled or punched in the pans and away I go. Then to build the new part of the evaporator to hold the pans.

[MartinP]

Ken,
Try to clamp something around the tube and then use ball pean hammer to slowly tap around the pipe inside until it starts to flare, then you can use the flat part to flatten it out. You may want to actually do it with the pipe in the hole in the bottom of your pan as even though they all look the same there are flucuations and unless the pan and flare match up good it will be hard to solder. Maybe even take a piece of plate and drill hole same size as your pipe OD, then use step drill to flare the hole, stick the pipe in the hole leaving a little sticking out, you could then take a rod slightly larger than the pipe and grind a cone shape on the end and hammer it into the pipe to start the flare and then finish in the pan. Good luck and you are right it takes a while to get it done right.

[StewieSugar]

28" x 24" Front, 28" x 48" Back. Both are 24" exposed to fire box/flue area.


I got 13 gph from the back pan and 5 in front.

I was curious how this compared to my rig and what improvement I might see if I made similar modifications. Here's what I came up with.

For your rig, I'm calculating about 1.4 gph per square-foot of surface area for the back pan, and I'm calculating about 1.1 gph per square-foot of surface area for the front pan.

My rig is a single flat pan that is 19" by 51" and gets about 7 gph, which works out to be about 1.0 gph.

Looks like we are getting comparable evaporation rates for our flat pans, and the addition of the through tubes is giving you a boost of about 30% efficiency in the back pan - or 17% overall.

This helps me a lot in figuring out what I might do to help boost my efficiency - thanks. Now I need to check into costs...

[KenWP]

To flare the pipes I found a peice of steel pipe the 1 inch fits inside and cut it about one quater inch shorter then the drop tubes. It worked well once I got the hang of it. Was able to do 20 tubes in a afternoon with out going to deaf. I then dropped in the thin slices of SS shaft and then belled the ends in and then drove the slice of shaft into the belled part tight and staked it with copper wire and soldered it. They look good and I have the flared end tinned and waiting for holes in the pan. This better work or else I will have to go to copper which went on sale for half price after I started this project.

[Gary R]

Stewie,

I have been making improvements on my flat pan. It is 24X54. I test fired 2 weekends a month ago. I was getting about 16gph. That comes out to 1.77gph/sq.ft. I think there are alot of area's where efficiency can be improved. The cost keeps climbing the more you work on it:(

[MartinP]

Ken,
I do not know how far you are from Grand Rapids Michigan but I saw this on the auction site and thought of you.
http://www.biddingatauction.com/listings/details/index.cfm?itemnum=818142700&ID=0

[KenWP]

Got my eye one of those at the local cheese factory. They replaced a lot of stuff this summer with the expansion they did and have a lot of goodies left over. havent been to town for a while to go over and check them out.

[RickinFarmington]

Today I fired up my barrel evaporator and tested the SS sink pan with the newly installed drop tubes. The results were beyond my best expectations as the pan boiled with such vigor I will now have to add an inward facing lip to the top edge of the pan to keep all the spashing under control. It is like 17 little volcanoes erupting at the same time.
I only hope the front syrup pan can keep up with the rear pan. Since I am not really concerned about the color of syrup, I will start off my levels in both pans three inches deep. Both pans boil very well at that level.
Anyhow, thanks for the drop tube suggestion. Can't wait to test it for real in a few months.

Rickin Farmington

[KenWP]

Did you solder all the tubes in. That is one thing I was wondering is if the tubes would erupt when hot. I was wondering if I would need to add sided to the pans to stop it from splashing so much. That or if the level of the sap in the pans would control the eruptions.
I just recntly got the holes punched in the SS sinks and have to start soldering them all in now. Did you use propane torch or did you use a hot iron. I have both ways to solder here plus a large electric iron.

[RileySugarbush]

I'm glad to see those are working for you. I was really pleased with mine when I first fired them up. I had the same eruption problem too. I threw a perforated stainless steel sheet over them and that helped break up the geysers.

[RileySugarbush]

And Ken, I used a propane torch on very very low flame. Tinning each hole and tube first, setting them in and then heating them to finish. Use wet rags in adjacent holes so you don't unsolder your previous work.

[RickinFarmington]

Ken, I also used a propane torch and pre tinned the holes before soldering the tubes in place. I just alternated from one side to another to eliminate the worry of unsoldering previously completed tubes.
I am fabricating some pan side extensions to fix the splashing problem.

Today I went ahead and drilled a hole near the bottom of my syrup pan and will solder a valve in place. This will eliminated the nasty task of lifting my syrup pan off the arch to empty it. This year I am running my syrup pan level as high as I can and still get a good boil. Who cares what color the syrup is as long as it is good tasting!

If the stock market keeps up the rally, I may spring for the bucks to have Bill Mason build me a custom pan to fit my barrel arch.

Good luck with the soldering.

Rick

[KenWP]

I'm glad to see those are working for you. I was really pleased with mine when I first fired them up. I had the same eruption problem too. I threw a perforated stainless steel sheet over them and that helped break up the geysers.

What type of preforated sheet we talking about and how much does it slow down the eruptions. I have some SS sheets and am wondering if I just drill holes in a sheet if it will work.
This week end will tell how close I am to getting anything done. Am finally looking at building instead of head work. Hands work better then my head at this age.

[RileySugarbush]

Ken,

It wasn't a perfect solution but it helped. It kind of rattled around as the big bubbles hit it from below, but reduced the amount of escaping sap.

It was a scrap of perforated stainless that was laying around. 18 ga with way too many holes to drill by hand! I think the holes were about 0.050" dia and spaced about .090", so that should keep you busy at the drill press.

You may be better getting some coarse stainless screen from McMaster

[KenWP]

Well got the first pan soldered up with the tubes in the bottom. Man what a job that is to do. Filled it with water and it poured water out on the floor. So had to go back and start over a couple more times and finally got it so that one leaks then ran out of solder. The next pan will be a better go of it now that I have figured out what all I did wrong on the first one. I have to figure out how to get the solder to stick just a bit better in places. I might try and weld the next tubes into the pan instead if I can find SS welding rods. I just hope that it boils as hard as it is to make.

[tylerj]

Hey there Ken.. you might want to give that pan a test boil when you are done just to be sure. The one sink I soldered held cold water just fine. However after testing it over a camp stove as the water started to boil it started to leak out the edge of the solder joint. Hot water leaks easier than cold water.

[KenWP]

That figures. I found SS welding rods today fianally. The guy asked what I was doing since I really had no idea what to get and he came up with something that he thinks will work. I know I can make it water proof with a welder or I think I can with a little work and patience.
I can see what I did wrong on the first pan when I was makeing the tubes for the second pan and I tried to correct those problems. They say that nothing short or indefatigable exertion can establish prefection.

[WESTVIRGINIAMAPLER]

If there are any small leaks, the burnt sugar on the outside will stop it off pretty quickly.

[KenWP]

I am really counting on that as I can't even begin to figure out where this goofy pan is leaking.
I am working on the other one and have learnt from my mistakes. I am trying to see if when I get it finished it doesn't have one leak from the get go. I was going to weld the tubes in but gave that dumb idea up as I can't get the welder to run at a low enough temp to not burn holes in thin steel.
Now for a couple warm days to finish that up and get the rest done and wait to use it.

[KenWP]

Spent this afternoon hunting down leaks in my pan. Seem to have them almost all found. I am going to try it as is with sap and see if it will seal up. if I do a test boil my water here should seal the cracks also as it has so much crap in it.
Waiting for a nicer day to do the other pan so that I can hold the torch barehanded. It is not the easyiest thing to do in the cold. I am hopeing that when it gets hot it holds also from the expansion.

[3rdgen.maple]

Ken do you have small drips or you talking more than that?

[KenWP]

Small drips. Sort of like just sweat on the tubes almost now. I did have real runny drips but found all those.

[adkrover]

I have a homemade rig that uses three stainless hotel pans and would like to add the copper drop tubes. Several posts have asked about connecting the drop tubes with t's at the bottom but I don't think anyone has given a response. Is there anyone out there who has tried this? To go even further on the idea, what about connecting the drops from each of the three pans together to make a draw off either from the front or side of the front pan?

[tylerj]

I have a homemade rig that uses three stainless hotel pans and would like to add the copper drop tubes. Several posts have asked about connecting the drop tubes with t's at the bottom but I don't think anyone has given a response. Is there anyone out there who has tried this? To go even further on the idea, what about connecting the drops from each of the three pans together to make a draw off either from the front or side of the front pan?

I have 4 s.s. sinks in a series that originally was going to be individual pans that I would laddle sap forward. I decided to connect them together with 3/4" copper underneath and coming up the centre of the sinks. The 2 middle sinks have 2 openings coming up.. one for the incoming sap from the previous pan and the other going to the next so that the sap goes in each pan as it progresses. My first test fire went okay but the water was boiling pretty hard out of the copper.. Spashing up 6 or 7 Inches from the copper pipe and I really didn't have the fire going very hard or for very long. I was a little intimidated by that (and with the flames directly on the copper) so I made a "V" shaped metal shield with some insulation in it to cover the copper pipe. My main purpose of the piping was to just connect the pans in series. I did a second test fire recently and it still boils pretty hard out the copper. We'll see how it goes come sap time lol. I have a couple individual pans in reserve in case of emergency.

[KenWP]

I would hope the copper pipe got hot enough to boil like that. To stop the boiling in pans built that way you would have to go to large tube. 2 inch copper would slow it down a lot. The good thing is that the sap will always level out when they are connected. I would like to join my pans also but then how to empty then becomes a mystery so will leave them separate and dip sap from one to the other.

[KenWP]

Today I finally got the other pan soldered up. To finally get it and the other pan to stop leaking I had to use anceint methods. I have a old electric soldering iron that has to be older then Hanyes and Fred. I ended up useing that as I found it impossible to get the leaks fixed with out remelting the other soldering. Works almost like a charm. Not perfect but it worked. Now to get the arch finished and see how they boil and if they leak under fire.
Just for the fun of it when the pan was full of water to test for leaks I put the propane torch to one tube to see if it did much. You could see bubbles start coming up pretty soon so i am hopeing with a decent fire they boil.
The math says I basically increased the surface area to 250% of the flat pan. That hopefully will show up in the evaporation rate.

[3rdgen.maple]

Ken good job about time you got the thing done. I am picturing the syrup shooting straight in the air and now you gotta build the sides higher. Ahhh just when you thought you were done.

[KenWP]

Already trying to invent sides for the stupid things. That or use the screen like Riley sugested. Tried to buy such a thing but no luck so far. I would hate to have to buy flat stock and drill a million holes in it myself.
For sides I was thinking of something like a box that just fits on the top of the pans that I can lift off again as it would be hard to handle them other wise. Will see maybe how it boils first to see just how high I need sides. She who has to be obeyed will not work on it if it spits at her. That I know for sure.

[3rdgen.maple]

Ken I think it would work good if you had sides that lifted off. Just make sure they go on the inside of the pans and not the outside.

[WESTVIRGINIAMAPLER]

If you are using copper drop tubes, they will boil much better than stainless as copper is a much better heat conductor. You will have a bunch of geysers coming up out of the pan.

[KenWP]

Well today was the big day. I got this drop tube evaporator running. I ran it with water first to see if it worked and then had to design higher sides. It spits it a good 16 to 18 inches in the air with a little surprise throwen in once in a while.
I have gone thru probbably 3 times as much sap if not more today since 2 then I could boil in a whole day. The drop tubes started to boil before the syrup pan did even. Am rather please with it. Of course she who has to be obeyed says now she can't wander off while its going now as you have to keep rather busy keeping it feed with both sap and wood.
I used SS tubeing with slices cut off of a 1 1/4 SS shaft to close off the end then welded. Works like a charme. If it boils this good with SS I wonder what copper would do.

[Peepers]

sounds like you need a stainless steel screen like a bacon spatter screen (but bigger) I've been thinking about getting one for cooking bacon, I use one on fishing trips with the guys but we don't have one here. last weekend the bacon got me pretty good with a big pop. ouch. :o

maybe someone near you sells stainless window screen by the foot like this stuff: http://www.amazon.com/Phifer-Wire-Products-3021497-Stainless/dp/B001CIWF1G/ref=sr_1_2?ie=UTF8&s=hi&qid=1267930079&sr=8-2-catcorr

might be $4 a foot but better than needing skin grafts...

[Z/MAN]

Well today was the big day. I got this drop tube evaporator running. I ran it with water first to see if it worked and then had to design higher sides. It spits it a good 16 to 18 inches in the air with a little surprise throwen in once in a while.
I have gone thru probbably 3 times as much sap if not more today since 2 then I could boil in a whole day. The drop tubes started to boil before the syrup pan did even. Am rather please with it. Of course she who has to be obeyed says now she can't wander off while its going now as you have to keep rather busy keeping it feed with both sap and wood.
I used SS tubeing with slices cut off of a 1 1/4 SS shaft to close off the end then welded. Works like a charme. If it boils this good with SS I wonder what copper would do.
Ken, You have to learn how to post pics. We're dieing to see your setup.
Paul

[KenWP]

Well I just got in from finishing up boiling 100 gallons in less then 12 hours. Last year I boiled 40 gallons in 13 to 15 hours. I would have done better but had to shut it down once to fix one of my screw ups and I was building my filter container also well boiling. Now that thats all done I can boil next time with almost no distractions. Am really impressed.

[BarrelBoiler]

boiling that fast it is best to do it with out distractions:D

[KenWP]

Well this goofy drop tube flue pan seems to be working well. I boiled almost 100 gallons today and made a bit lighter syrup then last year. The wind was bad and was slowing down the boil on me so I hooked up my blower that I made up. That got the pans smoking.
She who must be obeyed looked at my invention and figured that no way was she going to run it and she spent all day feeding it well I sorted out other things and hauled sap. She is even amazed how fast it eats sap compared to last year and she dosn't have to feed two stoves with wood in order to get 3 gallons a hour like we did last year.
My filter tank also works and I was able to filter 4 gallons of syrup wit hthe same filter and it ran through in record time.

[jayburd73]

instead of pricing hammer tubes try looking for testing stubs. plubbers put them in were the copper stubs out of the wall where a sink ,toilet ,washer, etc. would be installed. After the plumbing is preasure tested and the walls are finished you cut the end of the stub off and install the valve for the fixture. it keeps all the other contractors from getting compound, paint ,sawdust into the pipes.They are copper pipe that has a cap molded on the end. it is one piece and they are about 6 " long. Ive seen them at home cheapo. Ive only seen them in 1/2 inch. I bet if you go to a big plumbing supply store they could find bigger ones.

[BiddulphMaple]

i have a 40" x22"flat pan with 4 sections running across the pan. I have been reading this thread and am considering adding some SS drop tubes but was concerned that i might get syrup in the rear pan even before it gets to the front pan because of all the dividers. Is it possible that could happen?

[Otterguy]

I was just woundering if anyone has tried putting ribs on the inside of their sap pan? What I'm thinking of is making a heat sink on the inside of the pan with copper strips. Adding steel ribs to the bottom will add heat absorption but not incease surfase area. I'm thinking if I was to saulder flat copper stripps to the inside of my sap pan they would act like a heat sink and draw heat increasing the heated surface area inside the pan. I experimented with a pot of boiling water and put in a computer heat sink in it and pushed it against the bottom with a knife. The boiling action exploded around the heat sink as it drew heat up into the water. Copper readilly absorbs heat so if it was sauldered to the bottom of the pan it would heat up (obviously you couldnt use any thermal paste) Steal ribs on the bottom in the same locations would also increase heat absorption. The main thing is it would icrease suface area like a flue and should be easy to clean.