Dimensions for Flue pan

[Big_Eddy]

I'm planning to build a flue pan (finally) and am trying to work out the best usage given a 4x8 sheet of stainless. The plan is to bend the whole thing accordian like on the 8' dimension, then weld in the ends.

Looking at 8" sides, 3" shoulders, plus 6 flues at 5" deep x 1 1/4" wide, which theoretically gives me 1/4" left on the 8' sheet, and a 19 3/4" wide pan (I'll lose the 1/4" in there somewhere and make it 20").

I'll rip an 8" strip off the long side, to give me a 40" long pan and use the strip for the ends, flue ends and dividers.

Few questions for now.


For a 20x40 pan with 5" drop flues - are 8" sides high enough?
How high do the dividers need to be between the 3 sections?
Is there any need to bridge the bottoms of the flues together within a section?


I'll be back to ask questions about float valve boxes later - want to get the basic pan bent and assembled first. Will take lots of pictures as I know how we all love pictures.

[Bucket Head]

Eddy,

I would go at least double the height of the flues for sides. The boiling and foaming can get going pretty good. I had 6' flues with 9' sides originally and quickly found I had to fire it easy or I had more sap going down the sides than I had inside the pan, LOL. I ended up putting an extension on my flue.

I went with a divider 3" taller than the flues.

I also welded on a "brace" across my flues.

Check out the photobucket pictures. They are in the Modifications album.

Good luck!

Steve

[3rdgen.maple]

8 inch sides on a flue pan is way way way to low I have 18" sides and still get some sap splatterin over the sides it is a very small amount and not enough to worry about. The center divider is like 15" it is lower because of the top of the pan is tapered to help hold the splashing in. Put a drain in the bottom of the flues along the back on the bottom. This will give you the strength and the bonus of the drain. I would not go without the drain, the pan is way to heavy to pick of the arch to drain. Although some guys suck the flues out with a pump I would just rather turn a valve. You will probably have to get another sheet of stainless and weld a seam in there. Good luck with it and be sure to post some pictures.

[tessiersfarm]

I just did a very similar thing. I bent a pattern that our brake could handle and then designed the pan around that. Mine ended up 27" wide. Three issues come to mind.

1) How or Where are you going to bend the flues? I work for a Company with a state of the art fabrication shop and of the 4 brakes we have none will bend a 5" deep x 1 1/4" flue. The best I could get was 4" x 2". I ended up with 4" deep x a 3/4" flat with flue sides tapered another 3/4", leaving a 2 1/4" opening at the top of the flue. That was the best our equipment could produce without warpage from the bending truss.

2) 8" sides with 5" flues is going to require 13" ends or only leave 3" of side to the pan. Resulting in a 35" pan or too shallow pan depth.

3) Welding the ends on the entire pan is hard at best. We have some very talented welders and the best we have had a hard time with the deep corrugations. His suggestion was to build the flues seperate and then weld them into a flat pan bottom.

I have a hard copy of the plan I bent mine by I would be Happy to fax you a copy. I could even try to get my wife involved and try to e-mail it to you, but I don't know how without her. I left mine the full 4' long because I needed a second sheet for the front flat pan anyway so I took the end pieces out of that.

Good luck!

[Big_Eddy]

Bucket Head - I reviewed your modifications as part of the planning - Nice looking work. I was interested to see you welded the length of every flue. Lots of welding! Take your suggestion on the side height - may add extensions as you did - would make the seam in a more accessible place.

3rdgen - Thanks for confirmation on the side height needed and the suggestion on the drain - will see if I can do that without too much additional difficulties.

tessiersfarm - I have built a brake that can bend the flues. It was specifically designed to allow narrow flues to be bent. It is on here somewhere. I tested it last year with mild steel - bent the shape and welded up one end with no drastic problems. Nothing not acceptable in a home built pan. I TIG weld myself - would not put myself in the talented category - but I get by. I welded from the outside only, not within the flues and did not have a problem with access. I used a seperate piece for each flue end - then welded the fronts and backs on last.

One more question for now - 20 or 22 gauge ?
20 is easier to weld, harder to bend. Cost is pretty well a wash.

[tessiersfarm]

Mine was 20 guage, thats what the welder recommended. Stainless does bend harder than mild steel, I do not know the capacities of your brake but ours will do 16 guage mild and only 20 guage stainless. I really don't know that much about it only what I was told.

[Bucket Head]

Eddy,

I did'nt want to weld that much, beleive me! But I had to because I could not make a "one piece" flue of the height I wanted.

I had to make a "Z" or "S" (however you want to describe it) and then weld a piece of 6"x44" "flat" to it. Then I welded the ends on. Well, it was all tacked together first.

Twenty twenty hindsight shows me I should of, and could have made taller flues. I went with 6" so it would fit in the original pan. Seeing I had to put an extension on it, I could have gone higher.

Put as high a flue in as you can. Figure your pan height first. Surface area, or contact area with the flame is the name of the game here! I wish I had more!!

Steve

[Bucket Head]

Eddy,

Also, go with the thinnest St. Steel you can comfortably weld. The thicker the metal, the less heat transfer you have.

Steve

[PARKER MAPLE]

Just Curios As To Where You Guys Are Finding Your S.steele? Im Looking For Some Small Pieces, And Cant Find Them Anywhere.. Your Help Would Be Appericiated.. Thanks

[SGSyrup]

I'd like to build a pan, but have no idea where to start looking for the SS.

[Big_Eddy]

Just about every city will have a steel supply business - look up metal sales in the phone book. They are bringing in 2 4x8 sheets of 20 gauge - $236 CDN a sheet - which they will sheer to the sizes I want and sell me only the parts I need. They had to bring it in - will take 2 days to get - I can live with that. If you want small pieces - our local supplier had a number of drops of various sizes in stock - I got some to practice welding for pretty reasonable $$.

I've been holding off for a couple of years - cash is tight - but I have 4 cases of last years 500ml syrup left - so I figure if I sell those off, I'm ahead of the game.

We'll see how well the brake can handle the 20 gauge - I know I can weld 20gauge, I had some fun with 22 gauge. If the brake struggles, I'll reinforce it. :)

Will share progress once I start.

[PARKER MAPLE]

I Just Talked To A Dealer Near Me And He Said That 3 Pieces 1 Of Them 6in X 24in And 2 At 6in X 30in. He Said It Was Going To Cost Me Around 175$ American. That Cant Be Right Can It??? I Mean What Does 236 Cdn Transfer Into To American, And If Its Worth The Drive And Can Find A Dealer Just Over The Border I Will Go Pick It Up..

[nudlebush]

Hey Eddy I just got my pan back from the welder today that I bent using a brake I made from your plans.
I used 20g SS, the flues are 1.5" x 6" deep.

Can't wait to try it out Friday night

Nudell Bush

[Big_Eddy]

Nudlebush

You're ahead of me - I've had my brake made almost 2 years, and haven't bent any stainless yet. Lots of mild steel and test pieces.

I have the stainless in the garage - just been boiling or cutting wood instead.

I'm running 100 trees with a 2x3 pan right now averaging 4-5 gals/hr so it's been 14-18 hour days to keep up. Finally got a light day yesterday- got to sleep before midnight for the first time in a week.

[Peepers]

nice looking pan nudle. I'm a LONG way from doing a flue pan but I'm curious, do you guys typically put drains on each of the drop flues, have them T into a full-width drop channel at one end or pump the syrup out? Or is the answer "all of the above"?

The former-kitchen-sink pan that I'm using now still has the divider in the middle and it gets rocket-hot so I can see how the added heating surface from the flues is a definite bonus. When I graduate to the next level...

[nudlebush]

Right now we are using a sifon to transfer between pans, maybe our upgrade for next season will include draw offs....can't do er all in one year!

here is the best pic I have of our sifon

[SeanD]

Hey Big Eddy,

How did the flue pan work out? I'm at roughly the same point trying to get the most pan out of a 4x8 sheet of stainless. My math says I can get five 1"x7" flues with an inch between and leave 7.5" on the shoulders. However for a three foot pan that only leaves me three 12" sides. I have to get into another piece for the fourth side, but that might be okay b/c I'm planning on adding sections to my flat pan.

What do people think? The geometry leaves me a nice 12" on the length of the sheet for sides, but is that cutting it too close for 7" flues?

Another question I have is on the spacing between the flues. If I leave one inch between them the flues are all bunched together in the middle of the pan with 7.5" on either side (minus brick). It seems like the heat will scoot around the outside of the flues to get out as quickly as possible.

Should I leave 2" between the flues, leaving only 5.5" on the shoulders of the pan?

Thanks,
Sean

[PARKER MAPLE]

This Might Help You Or Not. But I Just Looked At A Brand New Leader 2x6 With Flu Pan. And The Flus Were About 3-4 In From The Sides, And Apprx 6-7in Deep, Leaving 1in In Between Them. Also I Think That The Sides Were Only Apprx 10-12 In In Hieght. Hope This Helps You Out.

Hey Ive Got A Question? Are You Guy Tig Welding All This To Gether? If So Is It Poss To Mig Weld Ss ? I Have An Old Mig Welder But It Dosnt Have Gas, So I Would Have To Get The Flaux Core Wire Right. Or Would This Not Work??? Puzzled Please Help Thnks

[SeanD]

Thanks, Maple Rookie. Do you remember how many flues it had? They probably used a piece of stainless longer than 8' I'm guessing.

As for the welding, I'm still learning, but without gas you definitely have to use flux core if you don't have gas for the mig. Check with your welding shop about which he would recommend for food grade stainless if it's even possible.

As far as I can tell so far (which isn't far), you can mig stainless. Get a bunch of scrap with the same gage to practice on to get to used to your machine and the settings that won't burn a hole.

Of course there are a bunch of experienced welders here who should probably take over from here.

[PARKER MAPLE]

Hey Thanks For The Info. I Believe That The Flue Stopped About 6-7 Inches From The End. If I Can I Will Get A Picture For You, I Got Buy There Often. Good Luck

[Big_Eddy]

Try to answer a few questions in one response.

SeanD - Dimensions - I used 3" shoulders, 6@1"x5" flues, with 1" between, but 1 1/2" between every 2nd flue to give me a bigger land to put the dividers on.(I had 1" extra to play with - made sense to put it there) which will give me an 18" wide pan when complete with 9" sides (full 96" used). I had a 9" strip sheared off the long side to give me a 39" long pan and the strip will become the ends and the dividers. I would think you would be better off with 2x7" flues 2" apart than having a wide shoulder on each side. The shoulder will act like a flat pan - whereas even a 2" wide flue has the sap surrounded by heat. I went with 6 drop flues rather than 5, as I wanted to evenly distribute 2 in each of 3 channels.

I asked my local steel supplier if they could get 10' sheets - they could, but only in 18 gauge and thicker.

Maple Rookie. I will TIG mine. You can MIG stainless and I'm better at MIG than TIG, but 20 guage is pretty thin and hard to work with using MIG. If you do use MIG, you have 2 options - Stainless wire with either C25 or Tri-Mix (preferred) gas, or Stainless Flux core wire which is rare and a roll will cost you about as much as your sheet of stainless (if you can find someone who carries it). I doubt you would be pleased with the results using your gasless wirefeed welder and I highly recommend you buy a small piece of material and practice, practice, practice before you start on your full sheet.

Progress Report - I have the flues bent roughly into shape - now working on a clamping device to tighten them up a bit and hold them for welding. Been way too busy boiling and at work to make more progress, and it doesn't look any better for the next 2 weeks.

[PARKER MAPLE]

Thanks Big Eddy For The Info. What Gauge Ss Did You Use In Your Project? And How Did You Go About Bending It? Im Am Lloking At A Gas Mig Welder From Home Depot. If I Buy The 4x8 Sheet Of S.s. And The Gas Mig Welder , I Think Im Still Way Ahead Of The Ball Sence How A New Leader Arch And Pans Have A Price Tag On Them That Will Scare You. Lol. Thank For The Info Again M.r.

[WF MASON]

Before I'd spend the $1000. bucks on a mig welder and steel , I'd be shopping for a used evaporator.
If your going to do it anyways , for years Miller made a econo-tig welder, 90 amps , for the same price as the mig your looking at.

[SeanD]

Thanks Big Eddy and WF Mason. Just for the heck of it I tried to MIG some very thin stainless scrap. I turned it way down and gave it a go. BANG! - there's a hole. BANG! - another hole. I'm huge into DIY, but not into throwing money away. I have a lot of learning to do ahead. Maybe things will improve be the end of the class.

I'll give TIG a try putting dividers in my flat pan on Thursday under the guidance of the teacher, but I may take a look at the used pan lists for a back up.

Anyone know of a cheap 2x3 flue pan?

Sean

[Big_Eddy]

SeanD / Maple Rookie

I concur with WF Mason

If your intent is to get a flue pan quickly and cheaply, I second WF Mason's recommendation to look at a used pan. If you look after it, you will be able to sell it later for what you paid for it so you're not out anything.

The best advice I can give you if you are big into DIY and really want to make your own pan is to think in terms of the 2011 season. Start by signing up for a welding course - preferably a TIG welding course - at your local college or similar. Get instruction and practice. Tell your instructor what you want to make, they will most likely accomodate you as best they can. There is nothing simple about welding in general, TIG welding in particular, and thin stainless is right up there on the difficulty scale. Take the time to learn to weld mild steel, then move to stainless and make a few floats, a few skimmers, a lot of test pieces, and finally try a flat pan for next spring.

As for equipment - a MIG welder is probably the most useful overall, but would not be my choice for Stainless work. The Econo-Tig that WF Mason mentions, Maxstars, or the new Milller Diversion are much better suited for maple equipment and are in a similar price range to the better MIGs. But if you aren't proficient at welding, no welder is going to make it easy. If you want more info on the welding aspects - I recommend a visit to the Hobart Weldtalk and Miller websites,

Third option is to follow nudlebushes example and bend your own, but have it welded up by a pro.

Not trying to put a damper on you - just trying to help you avoid buying the wrong equipment and wasting good material.

[PARKER MAPLE]

what gauge is suitable for making your own pan? and the next question is how would i bend my flues up? im thinking of upgrading for next season pretty heavly, i mean going from 30 taps on buckets out 100-130 on pipe. and making my own evaporator, out of a 275 oil drum. then in the future making enough syrup to sell and up grade to a manufactured unit. but thats my long term golls for this hobby, yes hobby , lol for know....

p.s is one of these oil drum evaps going to be able to keep up????

[Wattwood]

I'll jump on to Big Eddy's thoughts here.... What he said is exactly what we, or I should say my brother, did. I was lucky enough to find a couple of big sheets of +/-18 guage stainless. I hauled it around to a couple of welders in the area but couldn't deal with what they were quoting for the work. One couldn't handle the thickness and the other was too expensive. About that time my brother was taking a community college welding course. That was followed by a fabrication class where he had access to tig welders, brakes, and instructors who were a lot of help thinking through the details etc. (the instructors all have syrup in their fridge now) It worked out great because he learned how to weld with no material costs and I ended up with 2 super nice pans. 2x3 syrup pan and 2x2.5 preheater. We got just shy of 6 gallons of syrup after two weekends worth of boiling on 40 taps- will move up to 60+ next year. He also made up a cone filter/bottling tank and scoop with the scrap. Thanks big brother ya done good!

643
newly delivered pans w/ filter tank in back

639
first year setup. every piece of scrap block and stove pipe I could find...

640
valves between pans. we can rotate the syrup pan 180deg, valves in opposite corners, to help deal with sugar sand.

641
sweetened pans ready to go the next morning...should have shut one of the valves between the pans overnight!

[SeanD]

Believe it or not I'm in the class you mention right now and that's actually my overall plan. On my list for stainless are scoop, testing cup, stack cover, sections for the flat pan, and taking a crack at the flue pan - sort of in that order.

The stainless stuff moved way up on my list in the class because now that I've gotten pretty good at stick and MIG, I know I can postpone my other projects like an evaporator, grate, etc. that I can do with a stick or MIG to my own time over the summer/fall. I figure while I've got access to the TIG, the shear, many brakes, and two really good teachers I can see what I can do with them. Who knows? That's a good option having them bent up and letting a pro take it from there. Thanks for the tips.