making a wood boiler for radient

[Huntmaster86]

well after freezing my **** off again this winter im ready to make a boiler for my garage. I built a 48x48 garage 2 years ago and heated it with a small wood stove for the time being. As for my plan i bought a 1000 gallon propane tank to use as the boiler. I cut it in half and now its getting cut into quarters. Im going to use the 1/4 with the dome on the end for my burn chamber and the other 1/4 will be part of my water jacket which will wrap over top of the burn box. Im sure its not the most efficient method but im ok with that. The heat i get off the sides will just heat the air in the garage and the water jacket heat will be pumped through my floor.

My first question to you folks, how can i cut a hole for my chimney coming out of the radius of the "round cap" on the tank. Ill upload a picture to make it more clear to what im asking because im sure i will confuse some. Thank you and any input is welcome!!!!

 

[Huntmaster86]

 

[Huntmaster86]

The tank had a nice base on it when I bought it so I have some scrap metal to build the legs and for other projects.

 

[Huntmaster86]

I got the tank cut in 1/2 today and part of the cut to have it in 1/4's. Few more zip wheels and im golden

 

[Huntmaster86]

What I was asking is shown in the first pic. How can I make a template to cut the hole for my chimney on the radius of the cap.

 

[Huntmaster86]

I know everyone on here loves pictures so here's one of my garage.

 

[brewchief]

I've seen it done with half of a smaller lp tank inside the larger tank so the water jacket goes all the way around except for the end where a flat plate is used so a firebox door can be fitted.

To fit the chimney I would roll a piece of light cardboard into a sleeve the same diameter as the pipe you want to use and trim away with scissors until it fits where you want and use it as a template to mark and cut.

 

[Huntmaster86]

i guess i was over thinking it. thanks a very good idea!!! Thank you. I was going to do the idea you described but i bought this tank sight unseen thinking the diameter was smaller. The diameter of this tank is 41" so its a little on the bigger side. I wanted to avoid having the water jacket on all sides due to the ash deteriorating the metal.

 

[Bondo]

I wanted to avoid having the water jacket on all sides due to the ash deteriorating the metal.

Ayuh,.... I built mine with a propane tank, inside a huge commercial water softener tank,....

An inch of water under the inner tank, several inches above,...

This is after the outer tank was refit, 'n welded back on,....
The inner tank is surrounded by water, except for the door,....

Return water comes in the bottom, keepin' sediments from formin', 'n the hot water goes out the top of the back of the outer tank,....

 

[nadogail]

A hole saw will give you the hole I think you are asking about.

 

[Huntmaster86]

Bondo I was hoping you would chime in. Your boiler pops up a lot under Google search. I read through a lot of your posts. Pretty cool how you made your boiler and she'll out of recycled materials!! Props!!

What are the bars along the top of your burn box? Maybe that's just part of the water heater.

 

[Huntmaster86]

A hole saw will give you the hole I think you are asking about.

It may but an 8" hole saw is probably expensive and would be a ******* to drill on a radius at 90 degrees.

 

[walrus]

What I was asking is shown in the first pic. How can I make a template to cut the hole for my chimney on the radius of the cap.

plasma cutter

 

[Bondo]

Bondo I was hoping you would chime in. Your boiler pops up a lot under Google search. I read through a lot of your posts. Pretty cool how you made your boiler and she'll out of recycled materials!! Props!!

What are the bars along the top of your burn box? Maybe that's just part of the water heater.

Ayuh,... Thank you,....

The bars ya see are 2"x4" heavy wall box tubin', cut, fit, 'n welded into the firebox tank to create the front to back flue, above 'em, to reach the smoke pipe, goin' out the top,....
I turned each one, so's they're flat along the top, smoke area, 'n hi- low over the fire on the bottom,...
More square inches of transfer,...

For cuttin' the holes, I use my blue-tip wrench, 'n blow 'em out,....

I trim my pipe collar to sit on the tank where I want it,....
Hold it in-place, 'n rub a soapstone 'round the inside, 'n torch it out,....
The tiny bit of lip left, leaves a great place to run another bead of weld,....

Goin' down through the outer tank to the inner goes the same way, cut, 'n trim with the torch, grind it out, 'n when it all "Fits",...
Weld it into place, everywhere ya can get a weld on,...

 

[frostbiteoffroad]

well after freezing my **** off again this winter im ready to make a boiler for my garage. I built a 48x48 garage 2 years ago and heated it with a small wood stove for the time being. As for my plan i bought a 1000 gallon propane tank to use as the boiler. I cut it in half and now its getting cut into quarters. Im going to use the 1/4 with the dome on the end for my burn chamber and the other 1/4 will be part of my water jacket which will wrap over top of the burn box. Im sure its not the most efficient method but im ok with that. The heat i get off the sides will just heat the air in the garage and the water jacket heat will be pumped through my floor.



My first question to you folks, how can i cut a hole for my chimney coming out of the radius of the "round cap" on the tank. Ill upload a picture to make it more clear to what im asking because im sure i will confuse some. Thank you and any input is welcome!!!!

Weld a rod on center of the circle get some string and tie it to both rod and plasma or torch move slow for best results


Sent from my iPhone using Tapatalk

 

[EdT]

A decent book about drafting will show you how to develop the shape. If you google "development of cylindrical intersections" there is a lot of stuff too. I did not find a canned calculator for doing it, but there probably is one. Somewhere theres a thing that does templates for tube intersections, but I don't know if it goes as big as you need. For a practical solution for putting a hole in the big tank, take a straight cut piece of the chimney and position it where you want it to end up. Maybe tack weld it in place,. Maybe just hold on tight. Hold a full length pencil or similar device against the side of the chimney pipe and extend it down to make a mark on the tank. Repeat to create a series of dots all the way around. Connect the dots. Cut on line with your choice of cutter. With the same set up, you could probably put a light DIRECTLY above the chimney piece and then trace the shadow of the chimney pipe projected onto the tank.

 

[Huntmaster86]

worked the past couple days on the boiler and i was able to go back to the original plan of having a pipe in a pipe. I cut a 20" section out of what was going to be the "top" pipe and i was able to bend it to a smaller diameter. so as it sits now i have a 41" diameter outter pipe and a 33" diameter inner pipe. I had to use 3- 2" ratchet straps to pull it back together and then push down on the seam with the tractor to get is close to round.

yesterday i ordered up steel for the "caps" of the pipes and some 2x2 1/4 wall square tubing for the legs. Ill post up some pictures on my phone. more updates to come

 

[Huntmaster86]

Here is the start to my outter pipe


Here's the inner


We started off small cutting sections out of the pipe in fear that we wouldn't be able to pull it back together.


Welding the outside of the seem


Test fit.


I had some 6" Id pipe laying around and No 8". I priced out 8" and its $100 a foot. So I just whent with what I had. All my chimney is 6" so it worked out. Here's my buddy cutting a piece

 

[Bondo]

Ayuh,..... Lookin' Good,....

I welded 4 short pieces of 1" rebar to the inside bottom of the outer tank, for the inner tank to set on, which allows water flow round 360° of the firebox,....

 

[LS6 Tommy]

Looks good, but I'm still figuring out how you're going to make wood boil...

Tommy

 

[Huntmaster86]

Ayuh,..... Lookin' Good,....

I welded 4 short pieces of 1" rebar to the inside bottom of the outer tank, for the inner tank to set on, which allows water flow round 360° of the firebox,....

I welded a couple pieces of steel on the bottom but I'm going to weld some more on. I have rebar laying in the garage so that will get used. Thank you

 

[Huntmaster86]

Looks good, but I'm still figuring out how you're going to make wood boil...

Tommy

Lol I'll try like hell

 

[Huntmaster86]

I picked up my 2x2 and a 4x8 sheet of 1/4" steel today. Hopefully I'll get the legs made up soon. My buddy is letting me borrow his plasma cutter so I can cut my caps for the boiler

 

[Bondo]

Ayuh,.... I used 2" pipe couplers, welded to the outer tank for the "Ins", 'n "Outs" for the plumbin',....
1" is plenty, I happened to have a pile of 2" at the time, bushed 'em down to meet the pumps,...

Used 3/4" pipe couplers for the safety valves, 'n tridicators,...

Put 'em on before ya put the inner tank in, 'n it's easier to clean the water tank, just before ya slide the firebox it, 'n weld it up,....

 

[stihlntime]

My only concern is the water capacity. I've been around a lot of commercial made units like Hardy,Central Broiler,Wood Master,Earth etc. Based on personal expierence 200 to 250 gal water capacity is ideal. Units with 125 gal or less struggle on heating. My uncle is running the largest CB unit 800+gal to heat house and shop.

 

[Bondo]

My only concern is the water capacity. I've been around a lot of commercial made units like Hardy,Central Broiler,Wood Master,Earth etc. Based on personal expierence 200 to 250 gal water capacity is ideal. Units with 125 gal or less struggle on heating. My uncle is running the largest CB unit 800+gal to heat house and shop.

Ayuh,.... Mine's a measured 106 gallons,....

It has no problem heatin' this duplex 100 year old farmhouse, with 5 incoherent additions, that you can throw a cat through the wall, bout anywhere ya want,...

I fill it once or so a day right now,... a few sticks in the mornin' to get through the day, 'n pack it full at dinner time for the night,..

Last year at -20°, -35°, I was fillin' it 3 times a day, with 3 heapin' wheelbarrow loads of wood,.....

 

[stihlntime]

I agree it will heat with 106 gal, my sons run a firewood operation selling around and avi of 375 cord a year over the last five years with many customers owning wood boilers. It just seems that units under 125 gallons burn a lot more wood than units with a greater reserve capacity. Units with 200 to 250 gal capacity seem more efficient. I understand there are many variables, insulation, number of exchangers etc.

 

[ambenz]

I like the idea of using a actual hot water heater, even if it's one of those small apartment ones...check this out...

 

[LennyTheLizard]

My boiler is made nearly the same as what your doing. The firebox has a 6" space all around the firebox and 6" between back of firebox and back of waterjacket.

So Water jacket is: 48" Dia x 48" Deep
Fire box is: 36" x 42" Deep.

There's a 6" pipe going straight up through firebox and water jacket out the top.
When heating season is over, I'm going to switch my water lines. Hot water supply needs to come out the top, and it will get a good thermal siphon going.

 

[Bondo]

Ayuh,.... Nice lookin' stove,....

 

[Huntmaster86]

Ayuh,.... Mine's a measured 106 gallons,....

It has no problem heatin' this duplex 100 year old farmhouse, with 5 incoherent additions, that you can throw a cat through the wall, bout anywhere ya want,...


Last year at -20°, -35°, I was fillin' it 3 times a day, with 3 heapin' wheelbarrow loads of wood,.....

mine is in my garage and thats the only space i plan on heating it with now so im thinking it should be good.

yeah last winter was a cold one!!! I spent most of my winter months on your bay lol. I never made it up there this year unfortunately.

 

[Huntmaster86]

There's a 6" pipe going straight up through firebox and water jacket out the top.
When heating season is over, I'm going to switch my water lines. Hot water supply needs to come out the top, and it will get a good thermal siphon going.

did you leave any of the pips sticking down into the fire box to make somewhat of a secondary burn? I was contemplating leaving it 4-5" into the box. Anyone else do this? I know ive seen it on a few boilers on here just cant find em' again.

 

[TractorJeff]

I'm surprised the "Boiler Nazi's" haven't attacked this thread! Last year a guy wanted to build one and they were all over him about not being Certified.
I find Boiler concept construction interesting, but still question the efficiency as all the fellows I talk to seem to burn a lot of wood.
I do very much like the idea of the "fire" not being in the house or near it. Probably the same as Insurance companies do.
Keep up the good work!
Like the fact that so far all the material you are using is heavy as in my opinion this will minimize warping/cracking.

 

[Huntmaster86]

I'm surprised the "Boiler Nazi's" haven't attacked this thread! Last year a guy wanted to build one and they were all over him about not being Certified.
I find Boiler concept construction interesting, but still question the efficiency as all the fellows I talk to seem to burn a lot of wood.
I do very much like the idea of the "fire" not being in the house or near it. Probably the same as Insurance companies do.
Keep up the good work!
Like the fact that so far all the material you are using is heavy as in my opinion this will minimize warping/cracking.

Thank you jeff. Oh im sure someone will attack this thread, theirs always someone. Im glad i have my neighbor helping me. He built a boiler 8-10 years ago and he heats his 2200 sq ft house plus basement and his 32x48 garage. Last year which was a very cold winter here in upstate NY he only burnt 25 cords. granted his house was as 75 and garage at 70. I just love the concept of being able to open and close my garage door and not loose all my heat. also pulling my sled or tractor in during the winter months and having it melt and all the snow evaporate.

I was hoping to find a 1/2" thick burn box but this will work and if it doesnt well ive learned what to change for the next one. I love welding a fabricating!!! I made all of my armor and bumpers for my jeep.

 

[LennyTheLizard]

The pipe just barely sticks inside the firebox (maybe 1"). However, I would definitely recommend that you extend the pipe down into the fire box 4-5".

I've watched the flame and can see quite a bit going up into the stack. I think that extending the pipe will trap more of the heat against top of firebox and give you more time for heat transfer.

 

[Huntmaster86]

thank you, thats what i was thinking too. Helps prevent loosing so much heat out the stack

 

[Huntmaster86]

Ayuh,.... I used 2" pipe couplers, welded to the outer tank for the "Ins", 'n "Outs" for the plumbin',....
1" is plenty, I happened to have a pile of 2" at the time, bushed 'em down to meet the pumps,...

Used 3/4" pipe couplers for the safety valves, 'n tridicators,...

Put 'em on before ya put the inner tank in, 'n it's easier to clean the water tank, just before ya slide the firebox it, 'n weld it up,....

your system is pressurized i assume. I hadn't planned on pressurizing mine only because im not going to be the sole operator. with my work schedule my wife and nephew may be stokin the stove. thoughts on this?? or should i pressurize it and maybe an aquastat that controls the damper to potentially make things easier??? im looking for insite/ guidance to make it harder for someone to mess it up.

not being pressurized worst case is i have water on my floor from a boil over, worst case pressurized my stove blows up. Or am i over thinking this?

 

[Bondo]

Ayuh,.... I built mine pressurized to work with the existin' hydronics in the house,....

To test mine, I filled it with water, 'n pressurized it to 90 psi,...
No leaks, No explosions, at 3 times the operatin' pressure,....

I used 2 T&P valves for insurance against 1 gettin' stuck closed,...
My worst case scenario is the same as yers, an over-heated firebox, 'n water all over the ground from the 30psi T&P valves,...

Yes, Mine is All controlled by aqua-stats,....
Draft, pumps, All of it,...
In the event of a power failure, the whole thing shuts down, 'n the fire will go out from lack of air,....

 

[Huntmaster86]

do you remember where you got your components? the t&p valves i saw were 150-200 each or is that the norm?

do you have a build thread by chance?

 

[Bondo]

do you remember where you got your components? the t&p valves i saw were 150-200 each or is that the norm?

do you have a build thread by chance?

Nope, no build thread, it was pre-internet for me,.....

The pressure relief valves are the same ones as used on water heaters, oil/ gas boilers,....
3/4" in, 3/4" out, 'n the little over-ride lever on top,....

Maybe $20. a piece,....

I've got a Bud that works for Sid Harvey that gives me good deals,....
Actually, 'bout every contractor supply in the area knows me, 'n treats me fairly,....

You can keep askin' questions, 'n I'll keep tryin' to answer 'em for ya,....