Can I ask about a home-built wood stove ?

[Poodleheadmikey]

Great idea! Thanks.

I don't want a barrel stove - but buying the barrel stove kit would save me from having to build an airtight flange and door assembly.

PHM
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Build away!
(broken link removed to http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&productId=202398324&langId=-1&catalogId=10053&ci_src=14110944&ci_sku=202398324&cm_mmc=shopping-_-googlebase-_-D28X-_-202398324&locStoreNum=1273)

 

[Peter B.]

If you want to build something build a masonry heater.

Only problem with that is you pretty much have to build a house around it.

Peter B.

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[BrotherBart]

I don't want a barrel stove - but buying the barrel stove kit would save me from having to build an airtight flange and door assembly.

PHM
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The door assembly for a barrel stove is anything but airtight.

 

[VCBurner]

Insurance is important as freak things happen.

Burn technology has come so far in the past few years that if I were to consider building my own stove there would be no way I would do it w/out incorporating secondary combustion. Having burned stoves with and without this I can say that the difference is night and day and I'd never go back to a stove w/out this technology because of the less wood I use, longer burn times, and a cleaner chimney. The only thing my old stove (fisher) could do better was it could get the house up to temp faster. However, that was necessary since the fire was out 2 hours before I came home from work every day. With the new stove, I'm just as warm I just cant raise a 60 degree house to 70 as quickly as I used to, but I can keep it at 70+ no problem.

What concerns me about doubling back the flue pipe (from the front of the stove to the back then up) is that the extra 90's will slow and cool flue gasses and give you poorer draft and a great chance for creosote production. I'm sure I gain a few btu's because I have single wall pipe coming off of my stove instead of double wall, but I highly doubt the gain is really that great or else every new class A chimney would stop at the ceiling and single wall would be run up to it.

I know several guys running their own wood stoves. But they have insurance companies that have checked their setups and are OK with them. It's the only way to fly.

pen

As usual some thoughtful comments from Pen.

A big +1 for me on the secondary burn tubes and creosote producing heat exchanger. The Jotul 606 used to have a big heat exchanger on top. I heard those used to clog up really quick if burning green wood or slow fires. I like the idea of the tube steel body though. You could add blowers to some of those to really help the convection. The tubes could go through the top of the firebox. A clean burn and good amount of heat could probably be achieved by adding a baffle system and secondary burn tubes to burn creosote creating smoke before it exits into a straight flue. Then if you really wanted to go nuts with creating heat out of nothing add a round stainless steel catalytic combustor at some point before the smoke goes out to the connectors. The thing with cats is that they need some sort of heat absorbing usually refractory material to keep it from warping the parts around it. You could easily cast your own refractory parts. Look at the design of my stove in the link below to see an example of a cat placed on top of the stove. My stove has cat combustion air to cool parts under the cat and a refractory cover on top to protect the top of the stove.

 

[Dune]

I don't think you will see as much positive effect from the 3" sq. tube steel sides as you expect. For one thing, three inches is too big of a space. Two inches would be more apropriate. Do you have a bunch of tube steel in stock already? Tube steel is very expensive. Furthermore, it will take a ton of welding to make it that way. If I were totaly stuck on using that method, I would use something like 2"x 10" rectangular tube steel instead, and eliminate the majority of the welding. If this were my project, however, I wouldn't use tube steel at all, but rather I would use boiler plate for the entire construction and then make air passages where I want them, using just some 14 gauge steel.

As to the double bend, this is just not a good idea. What you want in ANY piping system, but especialy a stove flue is no bends, or as absolutely few bends as possible. If it were me, I would change the design enough to allow the vent to leave the top of the stove instead of the front. It could still exit from the front part of the top though, still giving you the full benefit of the smoke shelf. Good luck, and keep posting.

 

[Poodleheadmikey]

Square tube tends to be least expensive for me as it is a common arrangement. Rectangular tubes always cost more in my experience. Nonetheless; maybe the reduction in welding would make the tradeoff versus cost worthwhile.

The smaller the tubes - the more welding involved. Which is why the tubes are 3" rather than say; 1". <g>

BTW: there is to be no "stove top" - the top of the stove comes to a point: the apex of the trangular body shape. I guess I could have the flue connection at the rear - but that would eliminate the long horizontal smoke shelf idea. And the second flue passage is a primary part of the design idea.

BTW: I built the chimney myself. I do not ever have a poor draft issue. In fact; almost always the opposite - how to regulate the chimney draft down to low enough to avoid sucking the heat out of the firebox. <g>

PHM
-------

I don't think you will see as much positive effect from the 3" sq. tube steel sides as you expect. For one thing, three inches is too big of a space. Two inches would be more apropriate. Do you have a bunch of tube steel in stock already? Tube steel is very expensive. Furthermore, it will take a ton of welding to make it that way. If I were totaly stuck on using that method, I would use something like 2"x 10" rectangular tube steel instead, and eliminate the majority of the welding. If this were my project, however, I wouldn't use tube steel at all, but rather I would use boiler plate for the entire construction and then make air passages where I want them, using just some 14 gauge steel.

As to the double bend, this is just not a good idea. What you want in ANY piping system, but especialy a stove flue is no bends, or as absolutely few bends as possible. If it were me, I would change the design enough to allow the vent to leave the top of the stove instead of the front. It could still exit from the front part of the top though, still giving you the full benefit of the smoke shelf. Good luck, and keep posting.

 

[Poodleheadmikey]

Do any of you set up your stoves using combustion analysis equipment?

Adjust the draft with instruments?

Anything like that?

PHM
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[Poodleheadmikey]

Ordinarily: how large are secondary air tubes?

How critical is the pre-heating of the air? Should the secondary air intake piping run through the firebox itself?

1/2" black pipe? 3/4"? 1" ?

Or should the secondary air intake and distribution tubes be stainless pipe or tubing?

Can the pipes just end; open ended, inside the firebox? Say over or under the smoke shelf?

Or would a manifold arrangement be better? A horizontal run (or two? ) of pipe with, say; 1/4" holes every few inches along it's length?

Maybe an H-shaped manifold?

How much air volume gets added through a secondary air system? Should this perhaps be outside air?

I am asking because I have a long drive to think my way through this morning. <g>

PHM
------

 

[Poodleheadmikey]

Where can I buy an air tight door assembly?

Something that I can gasket/flange on?

Or something I can weld on?

Is anything like that available anywhere?

PHM
-------



[/quote]

The door assembly for a barrel stove is anything but airtight.[/quote]

 

[begreen]

Where can I buy an air tight door assembly?

Something that I can gasket/flange on?

Or something I can weld on?

Is anything like that available anywhere?

PHM
-------

The door assembly for a barrel stove is anything but airtight.[/quote][/quote]

Call around. My BIL bought a door assembly from Vermont Castings for his pizza oven. Can be done.

This old thread might be helpful to you. It's the about the building of a stove by hearth member Corie. This is a pretty sophisticated stove, but you get the idea. Take your time and do lots of research and drawings.

https://www.hearth.com/talk/threads/3735/

 

[Stump_Branch]

i say build on...with care....

while maybe some of the current stove works do more testing, r&D etc. it all started with someone tinkering.

here i have access to a full steel shop all the carbon and stainless i can imagine, just cant touch any of it for a stove....

 

[Beetle-Kill]

Yeah heck, go for it. I've got the full-on steel shop at my disposal also. If I had more free time, I'd probably build one myself. but when I can buy one for probably less than half of what it would cost me to make one, I shelve the thought and go on to the next thing.

 

[MishMouse]

For examples of different wood stoves and how they do their secondary air setup do a search of the web.
Allot of the companies Qudrafire, Harman, Napoleon, etc.. show cutout pictures of their wood stoves showing the detail of the air movement throughout the stove. Which could give you different ideas on how to setup your secondary combustion system.

 

[wkpoor]

My first stove was a hand me down one off built in a dumpster shop. Was actually built very nice, in fact you really couldn't tell it was homemade or shop made as it were. There was metal formed in a way only big shops or factories could do. But it had issues, like the door would try to warp itself when hot jambing the latch at the same time and creating an air gap too. The top would sag down in the middle even though it was 1/4" plate. The baffle would fall onto the fire quite frequently ( what a pain that was). In fact the whole stove was 1/4". Still the design was a little short in areas. Moral here, be preparred to make and test your design to the helt. I was sure glad when that thing left my house.

 

[Jimbob]

Pacific Energy sells their doors seperately. A door for the Vista might work for you.
(broken link removed to http://pacificenergy.net/pacificenergy/vista_classic.php)

 

[hotprinter]

I say forget the secondary's and instead put a cat in it. :roll:

REPLY:
I second that! I love our Blaze King with the Catalytic Converter in it. How about a Cat and secondary burn tubes like the Pacific Energy?

 

[scottperkins]

I really always love DIY projects and even if I spend the same amount, I always
feel my projects are heavier duty,and better built than "factory" items.
In your case, you could add in all kinds of "modular" components to assist in
keeping the heavy parts separate that can be added together. It is really
inconvenient to have a 700 pound stove to move around.
But before you start, consider again those barrel adaptors... Yea yea pretty
backwood hick but imagine stacking THREE of them . Overkill is always
a good thing... If tall ceilings, why not FOUR barrels stacked ?

Meanwhile, ever since I saw photos of the FREEFLOW wood stove I always
wanted to make one myself like you and have a firebox surrounded by
tubes to extract heat from the fire and move to the room. At this point
I am a little confused by todays technology as the current trend is to actually
do the opposite... that is insulate the firebox with firebrick to create a hotter
fire. Seems like less heat to the room but evidently the mfgrs claim more heat
ultimately moves to the room because of the hotter firebox even though it
is insulated.
Meanwhile, Id like to extract all the heat from the flue so I "could" use PVC
chimney.... ( dont laugh, modern hi efficiency natural gass heaters use PVC
plastic flues ) That would involve home made "heat savers" that were stacked
one upon the other all the way to the ceiling. Dont worry, I wouldnt actually
use PVC because of my self cleaning chimney aspirations.

For all those worried about creosote, I plan to design a chimney flue that is
self cleaning as is the case with electric ovens. Why not build a chimney
flue that can withstand a chimney fire that cleans it self out ever so often ?

The primary objective is to realize the maximum amount of heat
from a given amount of wood. That means as close as possible to complete
combustion and then extracting and retaining all of the heat before it escapes.

Let me back up and mention creosote again. It is not just the chimney fires
that are normally a drawback but creosote acts a an insulator and deterent
to heat conduction so that if the baffles in your "heat exchanger"
are heavily coated, less heat will be conducted.

One thing I have not seen is anyones firebox that had a turbocharger on it.
We all know that blowers are common for blowing air around fireboxes
but why not have a blower force heat into the firebox to create a blast furnace
forge effect ? Wouldnt that be another way to achieve more complete
combustion ?

OK there have been some pretty radical ideas presented... for the real
status quo naysayers.... remember they are only ideas. Pretend someone
has a gun to your head and you HAVE to find a way to make them work
instead of poo pooing them right from the beginning. Sure there
are lots of negatives associated with radical ideas and certainly
dont forget to mention them but also to focus and expand on the positives.
Heck this is just a forum and it its purpose IS DISCUSSION.

 

[69911e]

Great to do things yourself!
I bought a stove, but I changed it and will make another modification soon.
A few thoughts (worth every penny they cost and very possibly wrong.. ):
1: Secondary combustion is great. I suggest seeing yourself in person and playing with the air controls for a while to get an understanding.
2: The fire box must be very hot to get clean secondary combustion. Pull the heat off after this occurs using any cleanable exchange system you want to try.
3: I would buy a premade door with large glass. Significant radiant head comes thorough along with easy burn monitoring and most important enjoyment of the flames.
4: Design metal door flange at a right angle to door to minimize warping and increase contact pressure on door gasket without increased closing force.
5: Carefully monitor flue temps as you can pull out too much heat. Read up on condensing furnaces to understand why even oil burners are designed to not condense; thus their relatively poor efficiency.

Test outside your house with a representative flue if possible.

 

[Wood Duck]

Ordinarily: how large are secondary air tubes?

How critical is the pre-heating of the air? Should the secondary air intake piping run through the firebox itself?

1/2" black pipe? 3/4"? 1" ?

Or should the secondary air intake and distribution tubes be stainless pipe or tubing?

Can the pipes just end; open ended, inside the firebox? Say over or under the smoke shelf?

Or would a manifold arrangement be better? A horizontal run (or two? ) of pipe with, say; 1/4" holes every few inches along it's length?

Maybe an H-shaped manifold?

How much air volume gets added through a secondary air system? Should this perhaps be outside air?

I am asking because I have a long drive to think my way through this morning. <g>

PHM
------

In my Lopi stove the secondary air tubes are stainless steel, about 3/4 inch diameter, with small holes every inch or so. There are three tubes, maybe four, so air is evenly distributed across the top of the firebox. It seems like the gases and other stuff that burns up are spread out unevenly. Sometimes I see secondary flames in one part of the stove, sometimes another, and they move around. Maybe your peaked roof will result in secondaries always in the same area of the peak.

 

[Poodleheadmikey]

Peaked Roof -

I had been picturing the place to add secondary air as being Under the smoke shelf.

Would it be better to add secondary over OVER the smoke shelf? In the area inside the "peak"? That is: at the apex of the triangle shape of the stove body?

PHM
---------------------------

[/quote]

In my Lopi stove the secondary air tubes are stainless steel, about 3/4 inch diameter, with small holes every inch or so. There are three tubes, maybe four, so air is evenly distributed across the top of the firebox. It seems like the gases and other stuff that burns up are spread out unevenly. Sometimes I see secondary flames in one part of the stove, sometimes another, and they move around. Maybe your peaked roof will result in secondaries always in the same area of the peak.[/quote]

--------------------------------


[quote author="Wood Duck" date="1298486920"][quote author="Poodleheadmikey" date="1298397211"]Ordinarily: how large are secondary air tubes?

How critical is the pre-heating of the air? Should the secondary air intake piping run through the firebox itself?

1/2" black pipe? 3/4"? 1" ?

Or should the secondary air intake and distribution tubes be stainless pipe or tubing?

Can the pipes just end; open ended, inside the firebox? Say over or under the smoke shelf?

Or would a manifold arrangement be better? A horizontal run (or two? ) of pipe with, say; 1/4" holes every few inches along it's length?

Maybe an H-shaped manifold?

How much air volume gets added through a secondary air system? Should this perhaps be outside air?

I am asking because I have a long drive to think my way through this morning. <g>

PHM
------

 

[drumbum]

Check out husq445's build over at arboristsite in the wood heating forum; page 6 I think.

 

[MishMouse]

Check out husq445's build over at arboristsite in the wood heating forum; page 6 I think.

I recommend checking it out also, I commented on it so it will be more towards the front.
He shows pics of his build showing how he did his secondary combustion along with his air wash system.
It is a 4 cu-ft monster!!

 

[MishMouse]

Another place you might want to check is weldingweb.com as they have some people over there who are building there own stoves.

Though some of pics I seen over there they had some pretty big stoves very close to combustibles. :bug:

 

[drumbum]

If husq445 measured right it's 5.7 cu.ft.

 

[pen]

Here's a homemade double barrel stove from weldingweb.com

(broken image removed)

If you go to the thread about it you can see it's development. (broken link removed to http://weldingweb.com/showthread.php?t=47876&highlight=wood+stove)

Nothing fancy as far as secondary or catalytic action, but it's a beast w/ some serious steel.

I wonder how it would be w/ a cat between the barrels? Also lots of room to add secondaries preheated in the top barrel or along the back side.

pen