2x4 Drop Tube Flue Pan

[warners point]

It took a lot of work but I finally got it done. It has 144 3/4 inch x 6 inch copper tubes. I got the copper pipe for free from the guy who made the arch. I sure got a strange look at Menards when I bought 144 caps. My hands are still recovering from drilling out all the holes with a Lenox step bit. That was the worst part of all and I really had doubts after hole 20, but I just took it slow and spent about 5 hours drilling holes. I only had 12 slow drips with my first water test and fixed those and now I'm good to go. Thanks to RileySugarbush for the idea. I'm hauling the whole setup up to the sugarbush next weekend and will give it a real test then.

http://i297.photobucket.com/albums/mm207/bedublu/Maple%20Syrup/th_IMG_2138.jpg

http://i297.photobucket.com/albums/mm207/bedublu/Maple%20Syrup/th_IMG_2142.jpg

http://i297.photobucket.com/albums/mm207/bedublu/Maple%20Syrup/th_IMG_2145.jpg

[3rdgen.maple]

WOW that looks pretty cool. I cant imagine all the time it took. You might want to wear a life jacket when you fire that thing up, Im picturing sap shooting to the moon like old faithful at yellowstone. Nice job.

[warners point]

The sides of the pan are 12 inches and I'll probably have to make up some kind of shield for this year. Next year I'll have a steam hood and preheater over it.

[RileySugarbush]

That looks fantastic! I can't wait to hear how it goes

[WESTVIRGINIAMAPLER]

Nice job and I can't imagine how fast that thing will boil.

[Kev]

heck if you used 2 inch pipe it would have doubled as a fireworks launcher :lol: joking! looks neat!

[backyard sugaring]

Just wondering how the new pan is working? If you have a free moment let us Know. Pictures would be great. Thanks

[warners point]

I just did my first water test on Saturday. It was at a raging boil 10 minutes after I lit the fire. It seems like it will work really good. The only draw back I have noticed so far is that it is really hard to lift out of the arch. I can lift my side out, but the old man is shorter and can't get good leverage to lift it up and over. I'm going to install some pulleys, so we can maneuver it and drain it right over the arch. I'm also planning on building a walk way next to the arch for next year so the little people can watch whats going on. I'll let you know how it works and post some pics of it in operation.

[TimJ]

How did you make the connections between the copper and stainless? How about the copper caps - I don't suppose you can you use regular solder joints since it is right in the fire?

Would that be hard to fab for a newbie with little/no metal working skills?

[500592]

I know someone who made their pan corrugated so they could get more surface area

[warners point]

Is this hard for a newbie with no experience in metal work? No, that would describe me to a Tee. Just lots of research on this website and lots of hard work. I would guess that I probably had 40 hours into making it. All of the joints between the copper and stainless are silver soldered and the caps are also silver soldered. The solder has a high melting point, so as long as you keep liquid in the pan the solder will not get warm enough to melt.

[Kev]

How did you make the connections between the copper and stainless? How about the copper caps - I don't suppose you can you use regular solder joints since it is right in the fire?

Would that be hard to fab for a newbie with little/no metal working skills?
you can boil water in a paper cup... but every bit of the cup above the water line burns up. the paper can not burn as long as water is pulling the heat out of the paper.
the solder only has to withstand the 220 ish degrees of syrup

[TimJ]

Thanks for the replies guys. I am thinking of tackling this - we need to increase our evaporation rate (or rather we want to increase it) and a bigger evaporator is probably not the right way to go since we don't have enough taps.

[warners point]

Well I did my first boil today. This pan is awesome!!! I had about 150 gallons of sap that had to be boiled today and it took 4 hours to run through all of the sap. I figure it was going at about 40 gph. This was with just a natural draft coming in through the ash door and a copper coil preheater getting the sap up to 60 degrees entering the flue pan. Can't wait until next year when I add air and a real preheater. Finished it on the turkey fryer tonight and will bottle it tomorrow.

[Kev]

Well I did my first boil today. This pan is awesome!!! I had about 150 gallons of sap that had to be boiled today and it took 4 hours to run through all of the sap. I figure it was going at about 40 gph. This was with just a natural draft coming in through the ash door and a copper coil preheater getting the sap up to 60 degrees entering the flue pan. Can't wait until next year when I add air and a real preheater. Finished it on the turkey fryer tonight and will bottle it tomorrow.

way to go!
how high did the sap launch out of your firing tubes? :lol:

[wnybassman]

Well I did my first boil today. This pan is awesome!!! I had about 150 gallons of sap that had to be boiled today and it took 4 hours to run through all of the sap. I figure it was going at about 40 gph. This was with just a natural draft coming in through the ash door and a copper coil preheater getting the sap up to 60 degrees entering the flue pan. Can't wait until next year when I add air and a real preheater. Finished it on the turkey fryer tonight and will bottle it tomorrow.

You're gonna make me put drop tubes in my 2x4, aren't you? :lol:

[RileySugarbush]

Wow Bill, that is fantastic! I hope to head up that way late in the season to visit Sad Sam in Isle. Maybe we can connect then and I could see this pan run? I think we will be firing up Wednesday evening if you want to stop by here in EP.

[RickinFarmington]

I did the same thing though on a smaller scale. I run a blower system under the grates and have found that the fine ash starts to build up rather quickly on the from faces of the copper tubes. Being a small pan, I am able to lift it out and clean the tubes after about six boils. Other than that, it is nothing short of a multi vent volcano. Works well.

[wnybassman]

Are the tubes rigid, or secure enough, to really scrub them down hard? Inside and out?

[RileySugarbush]

Inside is easy. Scotchbrite on a slotted dowel with a cordless drill. They shine like new in second each. Outside is trickier to do mechanically because you don't want to push to hard sideways. I have used a brush intended for cleaning refrigerator coils. Oven cleaner works well too.

[len]

Perhaps a video of the rig at full boil? What depth in the pan for optimal performance? Is there a geyser effect below a certain depth? Lots of work- good luck with it. Looks like you'll have plenty of sap going forward this week!

[warners point]

I ran the sap depth around 1.5 to 2 inches and there was no issue with geysers erupting out of the pan. Taking a video of the thing at full boil will be impossible, because the amount of steam coming off is insane. Hardly any visibility and its no fun not running wide open.

[RileySugarbush]

I took a video of the first one I made with a steam table pan a few years ago. I gave them to a friend and they are still working fine.

You can find the clip here:

http://web.mac.com/jabushey/iWeb/Riley%20Retreat/Sugaring%202006.html

Here is a link to some construction photos:

http://web.mac.com/jabushey/iWeb/Riley%20Retreat/Sap%20pan%20construction.html

The four pans in that set up from front to back are:

Shallow 4" finish pan, 6" plain pan, two pans with the drop tubes.

[Ozy]

could you use tees instead of caps and connect all together in rows use a threaded plug at one end for cleaning cross tube at the other for a drain?

[RileySugarbush]

You could do that. It would certainly add some surface area. I think it would be a bit harder to fabricate with all the little pieces to solder and align.

I found the straight drop tubes a cinch to clean. A bit of vinegar and a piece of scotchbrite on a dowel in a cordless drill. You could do the same on your cross tubes.

[70 Buick]

Very cool setup
what are the "points" ?
could you just use a flat cap?

[RileySugarbush]

I made several of these out of steam table pans. Some with copper tubes and caps and some with water hammer arrestors. Those are copper tubes with the ends spun closed and look pointy.

[Waynehere]

Wow, just what I am looking for. Question though, not familiar with the greenlee punch. Googled and looked on eBay. Is there a difference with the mild steel and stainless tools? Did you use the mild steel tool?

Thanks

[Rugburn]

John, I dug up this thread and was wondering how (over time) the drop tube setup is working. I am considering doing the same thing and would love any pointers.

Thanks, Rugburn

[warners point]

After using this flue pan for a couple of seasons I have to say that I have no regrets in making it. The soldering has held up great with no leaks, even though it has been banged around a little lifting it on and off the evaporator. When I was boiling this weekend I was easily getting over 40 gph with just natural draft. The only draw back I have found is it takes a little longer to clean, but I don't mind.

[70 Buick]

after seeing this thread I thought I would try to make one
I got 1.5 inch SS tubing for free from a freind so we used that welded everything up
looks like hell as the steam pan warped with the heat but it doubled my boiling rate on my barrel
I had to keep it at 2 inch depth as anything under that the guysers jumped right out of the pan
there are 8 tubes 6 inches deep

http://shootthebull.freeforums.org/download/file.php?id=263&t=1

http://shootthebull.freeforums.org/download/file.php?id=268&t=1

[Rugburn]

Anything you would have done different (to those who have made them)? More tubes, less tubes? 3/4" or 1" diameter tubes. I'm sure it makes a difference whats on hand, but I will most likely be buying what I need (what I can't scavenge). My back pan is 2x5 with 11" tall sides, one divider. Thanks again guys!

[RileySugarbush]

As I mentioned before, I've built several. Some with upper water hammer arresters and some with tubes and caps. Tubes and caps are expensive and a pain to solder since you need to put the caps on last. Water hammer arrestors are easier but limited in length.

If I was to build another, I would use 1" copper tube, type M has the thinnest walls at .035. I haven't tried this yet but I would look into crimping the bottom ends flat and soldering them closed. After they are dropped and soldered into the pan of course. That should be the fastest way to close the bottoms.

[Rugburn]

Thanks a bunch for your input! I'll post some pictures when I get finished.

Regards, Dave

[Waynehere]

Thought I would update my experience on this project. I had a 2x3 flu pan that I had ordered pre-laser cut with 72 1" holes for 1" copper tubing. I had annealed all of the rigid copper, both ends, flared one end, dropped them into place and then squeezed the other end shut. I was getting ready to silver solder them in when my partner, who was playing horseshoes one night, had explained the whole idea to a buddy of his. Another player overheard and mentioned that welding the tubes would hold a lot better? Well, of course we were interested, but the guy wouldn't give us a price. Said he would work with us after he finished it. He worked at a dairy nearby and welded copper to SS all the time, and food grade welds too. So, after giving the pan to him in Sept. we didn't hear from him again until late Dec??? Wouldn’t' return our calls either. Finally heard back from him and he was going to drop it off in a couple of weeks? Of course it wasn't until3 weeks that we saw our pan back. It looked great, but it wasn't the original 18ga bottom we gave to him in it. He basically burned a lot of holes in the original bottom and had to put in a piece of 10ga in order to weld the copper to it. I was not happy to say the least, then gives us a bill for $800, just labor??? I could have soldered it for $100 or less. Sorry for the rant.... :(

So, as for the boiling, while we were using our dry wood, I was getting about 20 gph with auf. But I was only seeing it boil from the copper tubes, not the actually bottom of the pan, which I am pretty much convinced that the bottom is now too thick. The tubes were spitting sap out of the pan, so we had a 4-sided hood built that we could set just inside the pan that controlled it much better. We are going to try some tweaks over the summer, but I really hope to get the rate up from there. I was really hoping for some higher results, but I am kind of stuck with that pan for now. I still like the idea, but one thing I might do is try to put some more tubes in it. And I would highly recommend either welding/soldering it yourself if you know how, or get an estimate first. Lesson learned for me... :(

Wayne

[jfroe939]

Anyone ever thought of using copper roof flashing? It's only 10 feet long and 20" wide so that's the limiter, but it's only $95 also. Maybe one could make a 9-foot-long 1-foot-wide copper pan of it as opposed to a 2 x4 pan which would have the same surface area roughly speaking.

[70 Buick]

Anyone ever thought of using copper roof flashing? It's only 10 feet long and 20" wide so that's the limiter, but it's only $95 also. Maybe one could make a 9-foot-long 1-foot-wide copper pan of it as opposed to a 2 x4 pan which would have the same surface area roughly speaking.


yes but then you would need a 9ft x 1ft eveporator
I have never seen that size in a cataloge LOL

[Josh Nickles]

Thought I would update my experience on this project. I had a 2x3 flu pan that I had ordered pre-laser cut with 72 1" holes for 1" copper tubing. I had annealed all of the rigid copper, both ends, flared one end, dropped them into place and then squeezed the other end shut. I was getting ready to silver solder them in when my partner, who was playing horseshoes one night, had explained the whole idea to a buddy of his. Another player overheard and mentioned that welding the tubes would hold a lot better? Well, of course we were interested, but the guy wouldn't give us a price. Said he would work with us after he finished it. He worked at a dairy nearby and welded copper to SS all the time, and food grade welds too. So, after giving the pan to him in Sept. we didn't hear from him again until late Dec??? Wouldn’t' return our calls either. Finally heard back from him and he was going to drop it off in a couple of weeks? Of course it wasn't until3 weeks that we saw our pan back. It looked great, but it wasn't the original 18ga bottom we gave to him in it. He basically burned a lot of holes in the original bottom and had to put in a piece of 10ga in order to weld the copper to it. I was not happy to say the least, then gives us a bill for $800, just labor??? I could have soldered it for $100 or less. Sorry for the rant.... :(

So, as for the boiling, while we were using our dry wood, I was getting about 20 gph with auf. But I was only seeing it boil from the copper tubes, not the actually bottom of the pan, which I am pretty much convinced that the bottom is now too thick. The tubes were spitting sap out of the pan, so we had a 4-sided hood built that we could set just inside the pan that controlled it much better. We are going to try some tweaks over the summer, but I really hope to get the rate up from there. I was really hoping for some higher results, but I am kind of stuck with that pan for now. I still like the idea, but one thing I might do is try to put some more tubes in it. And I would highly recommend either welding/soldering it yourself if you know how, or get an estimate first. Lesson learned for me... :(

Wayne

Yikes Wayne!! Sorry to hear all of the grief you went through with that pan!! With all of the money you have tied up with it you could have bought a professional flue pan and float box. Too Bad, but we hear stories of "welders" butchering peoples pans pretty often on hear. Really makes you appreciate the professionals like Jim Schumacher who can weld miles of 22ga and make it all look like artwork. Best of luck on your next one, Josh.

[vttsa]

I'm considering doing something like this also, however I've never done any soldering before. I know i need to use silver solder and a propane torch and the appropriate flux and all, but I'm a little worried about getting the pans to hot and scorching/burning them. It's an English tin pan, and I would be using copper pipe. Should I worry about this? Any advice?

[RileySugarbush]

You could test solder a little spot on the bottom of your pan before cutting any holes. Clean a little spot with scotch brite, add flux, liquid like stay clean, use a very low flame on a propane torch and see if you can wet out a patch of solder. If so, you should be good to go.

To make sure you don't overheat any existing seams, lay down some wet strips of rag on any nearby solder joints.

[maple flats]

I'm considering doing something like this also, however I've never done any soldering before. I know i need to use silver solder and a propane torch and the appropriate flux and all, but I'm a little worried about getting the pans to hot and scorching/burning them. It's an English tin pan, and I would be using copper pipe. Should I worry about this? Any advice?
With english tin you could use regular lead free solder, the SS is what needs the silver solder. Leadfree solder is easier to solder with. One suggestion, measure the OD on the copper you will be using and get a Greenlee punch that size. You will be glad you did, the holes will all come out perfect and it will be faster and much easier to make the holes.

[mustanger]

This is a great thread and very informative. I sure appreciate all the great ideas presented here. Drop tube pans seem like a really great idea, but how do you get the sap out of them into your finish pans? It would seem to me that there is no flow through the system such as you see in other types of pans. This may be pretty obvious to a lot of you, but I don't understand and would appreciate someone explaining how it works.

Thanks

[RileySugarbush]

This is a great thread and very informative. I sure appreciate all the great ideas presented here. Drop tube pans seem like a really great idea, but how do you get the sap out of them into your finish pans? It would seem to me that there is no flow through the system such as you see in other types of pans. This may be pretty obvious to a lot of you, but I don't understand and would appreciate someone explaining how it works.

Thanks

It works just like a drop flue sap pan. There is lots of mixing from the violent boil. The sap level is kept above the top of the tubes, say an inch above the pan bottom. That transfers to the syrup pan as it boils down and is drawn down. When shut down between boils it just sits there. End of season, suck them out or tip it over. Cleanup is easy with scotchbrite on a dowel, spun with a cordless drill.

[mustanger]

Thanks John,

I appreciate the explanation. I have never seen an operating flue pan in my area. I know an Amish guy that has one and have figured it out. Guess those tubes must really pump the sap around. Tall sides would be a necessity. Looks like you would have to add sides to a restaurant warmer pan to get one to keep the sap in.

David

[Chemist]

I think I will put some copper drop tubes in my pan. However, I am wondering what kind of solder, flux or combination paste you used. I saw the muggy weld YouTube videos, but at $100 plus shipping for a syring I am wondering if there is a cheaper alternative.

[RileySugarbush]

I think I will put some copper drop tubes in my pan. However, I am wondering what kind of solder, flux or combination paste you used. I saw the muggy weld YouTube videos, but at $100 plus shipping for a syring I am wondering if there is a cheaper alternative.

Use any lead free solder if you have nice joints, meaning your tubes are flanged at 90° and about 1/8 wide so there is a nice solder area. Can use higher strength silver solder, but it takes more heat and is expensive. I used Harris Sta-Clean liquid flux. Remember, sand the surfaces clean, flux, tin both parts with a low flame, drop tube in and re wet with flux, join with low flame. Clean, clean, clean!

[Chemist]

Thank you. I was able to practice on some leftover stainless and copper caps. I am going to practice more befor I try it for real.

One. More thing, when you say to "tin" both pieces what does that mean?

[RileySugarbush]

http://mapletrader.com/community/attachment.php?attachmentid=14919&stc=1

Tinning is putting a coating of solder on the individual parts. It assures that both have a continuous ring of wetted solder to stainless or copper so there are no dry spots that cause leaks. Also much easier to do the final joint because you don't need to handle the solder, just the parts and torch. Here you can see a finished tube on the left and some tinned holes in a steam table pan on the right.

[Chemist]

15008

I made my first drop tube on a practice run using scrap stainless. I also practiced on some caps. It is not pretty but by the time I tried to do the copper tube it was getting better. I also drill the hole using a step up bit. Learning lots. Now it is almost time to do the pan.

Edit: I did my first two tubes in the pan today. I bought the Harris Stay Clean flux as John suggested. The silver solder tinned to the pan nicely with it. First flux I've tried that worked well on stainless. My tubes were capped later. Now I am leaving water in it overnight to see if it holds.

The tubes held. I put in two more today. However it took its toll on my step drill bit. I think I will go with four tubes this year and it they work like I think they will I can add more once the season ends.

[Chemist]

O.k. So I kind of can't stop working on this. I now have 6 more holes drilled to the 1/2 inch point which is the biggest bit I have until my new step bit gets shipped. Once I get that I'm now confident to do the final six tubes.

Then we will see how ten drop tubes that are 1/2 inch diameter and 6 inches of length work. My concern is the tubes will be too narrow, but time will tell.

[Chemist]

Finished soldering last night. Water tested my ten drop tubes. Two leakers. Fixed those today. Water tested today and not a drop in four hours. Here is Wisconsin it is tempting to tap soon, but I will wait a while.

Pan is nice and shiny after a good cleaning.

[Chemist]

Unfortunately, one of the drop tubes on my steam table pan started to leak a little bit on Sunday. Lost 3 gallons of concentrated sap.

It was on the last tube I soldered this winter. And, when I did it, I though the hole I drilled was a little too big. I will replaced it with a 3/4 inch tube tonight and it held water. All of the other solders have held very well.

This summer I will add some more 3/4 inch tubing to both of my pans.