wood stove questions and thoughts --please--

[bullfrogg]

hey guys,
I have added on to my shop twice now and I have been building a bigger wood stove to heat it. I have been using a small home style insert from TSC to heat prior to the additions. About a month ago I had a 300 gal propane tank give to me. Tag said it would 317 gallons. After cutting one end off it is still 42" round and about 50" long. It is a monster. I have built a front plate with a door( 17"x25" door ) grate, flue, and a 18" pipe on top for a heat exchanger. I really believe it will be enough heat( prolly to much ) but my questions are:

what about heating water with it to heat heat another room or the house like the outdoor furnaces you can buy? Has anyone done anything like this?
Any help would be greatly appreciated..

Here are some pictures of the last coupld of days. should finish tomorrow and will post more pics as I go.
thanks,

 

[trbomax]

There should be a baffle across the firebox and under the flue outlet. Pretty hard to put in now though.To properly heat water you need tubes inside the firebox too. You could maybe run tubes in the form of pipe across the top of the firebox ,under the flue collar,this would give you a baffle of sorts too. Are you going to have two doors on the front? you will need one below the grate (ash door) and a big one above it for loading. You will need a way to regulate draft air above and below the grates (two separate air regulating devices).What is the square tube? If its the stack collar its at the wrong end of the stove and should be 6 or 8 inch round. Also,not trying to bash,but those grates will colapse after 2 or 3 good burns,in this case they should be 3/4 to 1" square stock. They will get red hot on a good burn.

 

[Ric in Richmond]

Make sure you show that to your insurance agent too....he will really like it...

Biggest single source of fires in some parts of the country is homemade/ improperly installed wood stoves.

 

[brucer]

you could cut a large square section out of the top of the tank, weld a flat plate in, then add plumbing then mount the piece of tank you cut out back over the plumbing..

you would need to make sure the flat plate was welded in with no leaks..


or you could cut the back end off, add an insert/firebox from the rear then coil plumbing around the whole box..

friend of mine built a outdoor boiler, i could see if he could email me some pictures if you want..

 

[bullfrogg]

you could cut a large square section out of the top of the tank, weld a flat plate in, then add plumbing then mount the piece of tank you cut out back over the plumbing..

you would need to make sure the flat plate was welded in with no leaks..


or you could cut the back end off, add an insert/firebox from the rear then coil plumbing around the whole box..

friend of mine built a outdoor boiler, i could see if he could email me some pictures if you want..

That would great, if you don't mind.


There will be a flue baffle in it.
I also thought once I put 18" pipe heat exchanger on top I could put water pipes in it .

 

[bullfrogg]

 

[Buckgnarly]

Out of curiosity, how did you purge and cut the tank? Gotta be hard to make that first cut....

 

[brucer]

Out of curiosity, how did you purge and cut the tank? Gotta be hard to make that first cut....

i was wondering that myself...

nice looking pooch in your avatar.

 

[bullfrogg]

I read and read about cutting it. I didn't, I had a buddy do it lol !!
I filled with water then drained it, then I filled with soapy water and drained it. Then I poured a box of tpn in it, filled with water and drained it, then again with palmolive water again then made first cut while still full if water.

 

[LoanRebel]

looks really cool.

 

[trbomax]

The second chamber is a good idea. At this point a rectangular angle iron frame around it, covered with sheet metal would provide a good way of capturing the heat,mounting a blower,and directing the heat where you want it.

Cutting a section out of the firebox and attaching a coil or set of tubes,then welding the removed section back in would work.I would use 1" or 1 1/4" steel pipe,makeing at least six passes, and welding the "U" sections on,not useing cast threaded fittings. I realize that not many people have acess to a mandrel bender so if you could get steel threaded fittings and fab the coil up useing them,you could then weld all the connections solid ,that would be OK. I wouldnt worry about the shell leaking where you weld it back in,it apears your skill with the welder is more than adequate. I would make the coil or tube unit out steel pipe and pressure test it to as high a pressure as you have available.

 

[brucer]

heres some picture my friend emailed me..

he heats his house, water and has a combine radiator as a heat exchanger in his shop..

 

[bullfrogg]

Thanks for pictures. I'm gonna keep studying on it.
Also thanks fir all the ideas ..
I hope to have it done tonight.

 

[bullfrogg]

Almost done .

 

[burleymike]

It is probably too late to do it easily but if it were me I would add some burn tubes. Take a look at any modern wood stove and see how they put a refractory baffle on the ceiling of the firebox with some perforated stainless tubes under the baffle.

You route the air supply to the tubes through the firebox so the incoming air gets pre heated. You will have a much hotter fire. All that smoke that goes up the chimney will burn this way and give you more heat and less creosote.

If you use single wall pipe in the shop you might wrap it with something like Roxul or kaowool to help keep the flue gasses warm giving you a good draft. It will also stay a hell of a lot cleaner.

I remember a few years ago seeing a similar stove in a shop. The guy would load 4' long logs into that sucker and boy did it throw some serious heat. Nice not having to split all that wood as well.

 

[bullfrogg]

Thanks,
I got it done and moved to it's spot tonight.
It puts off great heat, with little wood, but it smokes bad when I open the door. Iguess maybe my flue baffle is to restrictive??? Im gonna cut some of it out in the morning and see how it does.

 

[copterdoctor]

I wish you luck, and hope you have good insurance..... my neighbor (2 doors down) just had their house burn to the ground last week because of a home made wood stove... doesn't look like you addressed many, if any, of the concerns brought up earlier in this thread... like I said, I wish you luck.....................

 

[bullfrogg]

I wish you luck, and hope you have good insurance..... my neighbor (2 doors down) just had their house burn to the ground last week because of a home made wood stove... doesn't look like you addressed many, if any, of the concerns brought up earlier in this thread... like I said, I wish you luck.....................

What concerns?

 

[lzenglish]

Thanks,
It puts off great heat, with little wood, but it smokes bad when I open the door. Iguess maybe my flue baffle is to restrictive???

You do nice fabrication work bullfrogg, but why did you decide to put the exaust near the door, rather than in the rear of the stove? I believe this is your main smoke problem when you open the door. I know that hinsight is always 20/20, but I would also be inclined to put the baffel in the main stove, so as to force the flame to roll around it before it exits. Then mount your water coils above the baffel, and just below the exaust. This will help to reclaim as much of the firebox heat as possible.

Good Luck,

Wayne

 

[bullfrogg]

Hey Wayne,
Thanks, yes it's 20/20. I did it because where I had my stack already and I wanted the exhaust to go around it top tube not just one pass. There will be a pipe in the rear tomorrow. I also think this will help. We'll see
Thanks

 

[trbomax]

After looking closer at your first pics,is the square tube the flue connecter between the upper and lower parts of your stove ? If it is ,is the area larger than your flue stack? Doesnt look like it. If you are running an 8" stack,that connecter needs to be at least 50 sq in. Why is there a damper in that connecter? Should not be there. An airtight stove does not need a flue damper at all,the draft should be regulated by the combustion air intake.

edit) another thing,how high above the roof penetration is the top of your stack? It needs to be 4' higher than any point on the roof within a 10' radius of the top of the stack.

 

[lzenglish]

An airtight stove does not need a flue damper at all,the draft should be regulated by the combustion air intake.

I agree with you, that you don't absoulutly need one, but I would not own a stove without a flue damper! Both factory made stove's I have owned had them, and it increases your BTU output allot! So you get more bang for your buck out of a cord of wood.

Bullfrogg: By the way, where is your air inlet located? I don't see it in the pictures?

Wayne

 

[lzenglish]

An airtight stove does not need a flue damper at all,the draft should be regulated by the combustion air intake.

I agree with you, that you don't absoulutly need one, but I would not own a stove without a flue damper! Both factory made stove's I have owned had them, and it increases your BTU output allot! So you get more bang for your buck out of a cord of wood.

Bullfrogg: By the way, where is your air inlet located? I don't see it in the pictures?

Wayne

 

[trbomax]

I agree with you, that you don't absoulutly need one, but I would not own a stove without a flue damper! Both factory made stove's I have owned had them, and it increases your BTU output allot! So you get more bang for your buck out of a cord of wood.

Bullfrogg: By the way, where is your air inlet located? I don't see it in the pictures?

Wayne

A flue damper will lower the flue temp and by shutting the area of the flue down it slows and cools the gas temp,causeing both creosote build up and condensation.Put a flue temp gauge on the flue ahead and behind the damper. Then burn a good fire with the damper full open and record the temps. Now shut it down and after at leaqst 10 min. operateing it that way ,record the temps. Any temp under 350 degrees is makeing tar and moisture.

 

[Spareparts]

When I built one several years ago we used a old boiler and used it upright, took up less room.
i believe it was 42"X 66" long or tall after we stood it up, and used old plow shears for the grate, they lasted for several years (at least 10) and the plate under the flue exit is refered to as a "smoke shelf" and causes the air to circulate around before it exits the stove. The old shop was 36'X60' and in the coldest days you could work in a T-Shirt.

 

[Need4racin]

there's some vids on youtubes of building wood stoves.

 

[bullfrogg]

The air intake is not in any pictures. It is on the left side behind the front plate. It too is made from the 6" square pipe. I'm going to make a damper for it and ad the second stack today.

 

[BUDD]

i can give you a little advice on woodstoves i spent 15 years at Pacific Energy
woodstoves, allot of the time i worked in R&D, i also am the owner of the
trademark name FISHER WOODSTOVES, some of you old guys may remember them, i'm
currently working to reintroduce them back on the market, all stoves today must
meet safety and EPA, to meet EPA your stove has to burn clean and there are two
ways of doing this, one is to use a catalytic converter and the other is to use
secondary combustion air, for safety it has to do with distance to
combustibles and max flue temps, flue temps are not to go over 1000 degree
measured at around 20 inches above the unit, wall temps surrounding the stove
must not exceed 160 above room temperature, something like that, anyway your
stove looks fine if your 3/4ft from a wall and you have good flue pipe thats
not going through any wood, as for being efficient, if i were building that
stove i would put as large a piece of ceramic glass i could find in the door,
light coming from inside your stove equals radiant heat, heat that goes up the
flue other wise, secondly i would add secondary air, i would make myself a nice
baffle under which i would ad 6 or 8 1" DIA tubes with holes 3/16" pointing
straight down, what you want to do is heat up the wood to the point it releases
its gas and then com-bust that gas, you will burn way less wood, your primary
air should not come in right at the bottom of your stove it should come in
about the door pointing downward flowing over the glass in the door, a small
boost air tube coming in below the door would be enough to get the fire going,
hope this helps. the shutter between the fire box and heat exchange is
pointless.

heres a pic of some secondary air tubes, their holes point sideways and thats done to increase the burn time at testing, grams per hour, the more hours the burn lasts during a test the better, in your case its less of a concern, you just want to be warm.

 

[bullfrogg]

Well I put in the second stack between lower and upper tank, and yes still smokes like hell when I open the door... What now ??

 

[trbomax]

refer to my post # 21 re the hight and draft of the chiminey.

 

[BUDD]

one thing to try to control smoke coming out the door is to open it a crack, wait till your flue starts drawing again and then open the door slowly, that process is quite common on current stoves, sence your still in the R&D part of your woodstove i think i would try running it without the heat exchanger, make your flue come straight up near the back/top of your stove, a baffle is a good idea, you could just weld some tabs on each side of the fire box inside so a baffle plate would just rest on them, the baffle should sit higher then the top of the door opening and run from the back and leave about 8" from the front open, it's a fine balance to have a stove burn well but not burn like a house on fire, do you have pics of your flue? also if you don't have access to ceramic glass you can use a PYREX dish, just something so you can see what's going on in there when your burning, tempered glass will just explode, ceramic glass is safe as you can even take a torch and melt a hole in it without it shattering.

 

[sberry]

Speaking of stoves, just took nine 5 gallon buckets of ashes out of mine this morning.

 

[usafmora]

all stoves today must
meet safety and EPA, to meet EPA your stove has to burn clean and there are two
ways of doing this, one is to use a catalytic converter and the other is to use
secondary combustion air, for safety it has to do with distance to
combustibles and max flue temps, flue temps are not to go over 1000 degree
measured at around 20 inches above the unit, If this statement is true then why did I just buy a Wonderwood Stove from rural king. It has neither a reburner or a catalytic converter. Enclosed is the list of wood stoves certified by the United States Environmental Protection Agency (EPA). An EPA certified wood stove or wood heating appliance has been independently tested by an accredited laboratory to meet a particulate emissions limit of 7.5* grams per hour for noncatalytic wood stoves and 4.1* grams per hour for catalytic wood stoves

 

[swvega]

Back in the early 80s I took and old iron fuel oil stove that stopped working and removed the burner. Then made a 1/4 thick steel box that I welded to the opening where burner was removed with a barrel stove door on it. You could put about 24" wood in it. Once it got hot a little you turned on the fan and let her rip. It would heat a poorly insulated pole shed in -0 weather here in mn. Had it for several years with no issues. It would heat the shop to 80-85 if you packed it enough.Had a guy that brought me old pallets for free and thats what I used most of the time.

 

[BUDD]

your stove is exempt from EPA, it is either called a frunace or the air to fuel ratio is such that EPA doesnt apply, lots of pellet stoves fall under EPA exempt do to air to fuel ratio, the effency goes down when the air to fuel ratio goes up, i guess i should of included the EPA exemptions in my coments.

all stoves today must
meet safety and EPA, to meet EPA your stove has to burn clean and there are two
ways of doing this, one is to use a catalytic converter and the other is to use
secondary combustion air, for safety it has to do with distance to
combustibles and max flue temps, flue temps are not to go over 1000 degree
measured at around 20 inches above the unit, If this statement is true then why did I just buy a Wonderwood Stove from rural king. It has neither a reburner or a catalytic converter. Enclosed is the list of wood stoves certified by the United States Environmental Protection Agency (EPA). An EPA certified wood stove or wood heating appliance has been independently tested by an accredited laboratory to meet a particulate emissions limit of 7.5* grams per hour for noncatalytic wood stoves and 4.1* grams per hour for catalytic wood stoves

 

[SgtRauksauff]

here's the 30+ year-old barrel stove currently in my father's garage:

notice the round air intake on the upper part of the door. Behind it, is a channel that actually brings the air in at the bottom, but the stack is at the back. So the draft from the chimney moves the incoming air across the burning wood.

I think that even if you do have a good draft from your chimney, because of the exit being right above the entrance, the air path is very short and does not go through your combustion chamber very well, thus not going over your fuel very well, so it only smolders instead of burning cleanly, causing your smoke.

I think the combustion chamber air path needs to be fixed, and I think the easiest way to do that at this point is to move the combustion chamber intake to the back, so you get decent flow and clean burning of your fuel.

Just my opinion, I'm no injuhnear.

--sarge

 

[bullfrogg]

Well, I added the 8" stack from the top tank all the way out and about the roof. It helped some but nit completely. Before if I barely cracked the door open, smoke would roll out like crazy. Not after the new stack I can open the door about three inches before smokes comes out. It don't roll out like before, but it still comes out.... Now what!!???

 

[bullfrogg]

Any more ideas out there... I just added 4' to my stack and I also cut open the top tank and removed the baffle.. Still smokes like hell when I open the door..
Any help is appreciated..