Wood burning indoor stove?

I think the choice of material has to do with (a) the quantity of heat and (b) the rate of heat absorption and the rate of heat dissipation, which I guess is equal for any one material.

A stove puts out a lot of heat - it gets absorbed slowly by cast iron or stone - it dissipates slowly from cast iron or stone.

Heat sinks: Relatively small amounts of heat that must be discipated in a hurry.

PS: In summary, the choice of material has to do with the application and the rate of heat transfer.

I for one would not want to have a cast aluminum stove in my place. Its melting point is pretty close to the temps a lot of stoves are more than capable of reaching or topping. My Vermont Castings has approx 650 to 700 deg firebox temp, with about 400 deg stack temp, but if I use the cat convertor the discharge temp is in the 1600 to 1800 deg range. I have already had a firebox temp of over 1200 deg when the son left the draft unattended for a short period of time, which is pretty close to melting point for aluminum. The heavy gauge stailless flue pipe and the attaching collar at the back were glowing a nice bright red. Aluminum does get pretty soft at elevated temps. I would also think that if Aluminum was a suitable material you wuld see at least one manufacturer using it as such as it certainly is eaiser to cast and use than CI would be. I guess it wold work, but a first time screwup could be disasterous.

Just my view

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expressed are those of my wifes, I had no input whatsoever. Remove "nospam" from email addy.

I would have thought that the upper temperature would be too high for aluminium. Steel wood burning stoves run to 600F surface temperature with the inner parts higher still. If you go for a clean burn design like my last one, there is an internal baffle plate which used to reach dull red. Aluminium has good thermal conductivity so may run cooler. That is not always an advantage as low temperatures within the combustion chamber can lead to other problems. One further thought, would the rate of corrosion of the aluminium increase dramatically at the higher temperatures? After all, the stove will be sitting at high temps for many hundreds of hours.

John

Aluminum will melt or get very soft at the temperatures encountered in a wood stove. It also has a relatively high coefficient of expansion. It wouldn't take much of a fire to melt holes in the walls of the stove or to distort it completely out of shape.

Ned Simmons

Jack, the stove would melt. One night, after turning off the lights, I noticed my wood stove was glowing a dull red. If it had been aluminum it would have at least sagged. You could bolt al. heat sinks to the outside of the stove and blow a fan across them. But a stove made solely out of al. wouldn't last long. However, it at least would be easy to carry out. ERS

Ever see a wood burning stove glow? If made of aluminum, it'll melt.

Pete

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Jack Fisher wrote:

Yeah, one thought: DO NOT EVEN THINK ABOUT DOING THIS UNLESS YOUR GOAL IS TO BURN YOUR HOUSE TO THE GROUND! That's exactly what you'll end up doing if you try.

Woodstoves (the normal cast-iron type) can VERY EASILY get hot enough to glow a clearly visible cherry red when the lights are out. Aluminum at that temperature is, at the very least, going to warp and/or sag hugely, if it doesn't literally melt into a puddle.

Al is used for heat-sinks because it efficiently transfers heat. Al ISN'T used in high-temp applications because it has a low (VERY low, relative to iron) melting point.

DON'T DO IT! Use whatever method it takes - a long talk with a priest, a ballbat to the head, a large bottle of booze, even a high-dive into an empty concrete swimming pool - to squash this idea before it gets acted on and gets you or somebody who lives with you burned out and/or killed. It's one of those classic "looks great on paper, but isn't worth the paper it was drawn on in reality" ideas.

Don Bruder wrote: I know most wood burning stoves are made from cast iron, but I was wondering about making one from cast Aluminium? ^^^^^^^^^^^^^^ I have welded lots of aluminum with an acetylene torch, and I can tell you that it does not reach red heat before melting. So, all the folks who have seen their cast iron wood stoves glowing a dull red are right. Your stove would be dangerous. Actually, aluminum is what they call "hot short." This means that when it is hot, it becomes weak and brittle. Welders know this, and always support the work to keep it from breaking apart.

>

Say goodbye to your house! You'll have a tough time getting any insurance payout, too!

A wood fire is quite capable of turning an aluminum stove into a molten puddle.

That would be a bad thing to have in your house.

Most wood stoves these days are made of bent and welded sheet steel. The cast ones sell at a premium, to people that want the "look" more than the heat.

Cheers Trevor Jones

Thanks for the input folks. I was not aware of how hight the temp gets in a wood burning stove.

Jack

The woodstove that heats my hot tub is aluminum but all but the firebox door and chimney connection are submerged in a large tub of water. No water=melted stove.

Ummm... Leo?

Please pay attention to what words you're putting into whose mouth in the future. After your job of trimming, the fact that I was *QUOTING* what Jack wrote, rather than being the author of it, is completely lost.

Lesser things have produced flamewars and damaged reputations. Trimming for size/clarity is good. Trimming so extensively that the attribution is lost is bad.

Don Bruder wrote: (clip) Trimming so extensively that the attribution is lost is bad. ^^^^^^^^^^^ I apologize. I meant to attribute the quotation to Jack Fisher, the one who asked the original question. Clearly, your post indicates a correct understanding of the subject, and I only meant to add to it from another perspective.

Jack, if you design a lining of firebrick that will insulated the aluminum, also cuts down on heat generated for the space. Maybe a heat exchanger(steel tube) run thru the firebox will make some heat. it's not going to be cold! brrrrrrrr

tt

Case history: Got a wood stove for a cheap price and went down to the Home Depot looking for stovepipe for it. Found some double wall stuff and put it to the stove. After cleaning from the first fire, I saw some white metal in the back of the stove and wondered what it was. A quick look at the pipe and roof vent didn't show anything wrong so I suspected that it was solder from a third piece of pipe that I put over the double walled stuff to use as a forced air supply of hot air. After a few more burns, there was more of the white metal and I noticed that the area near the exhaust vent was charring even though I was pulling air from that area. Pulled the pipe apart and found that the pipe itself had melted much of the inner part, leaving the exhaust to go into the house as much as out the end of the piping. Replaced the dual wall with some 6" and 7" steel pipe and the problem hasn't come back. I'll also note that the forced air is hotter than it was but the exhaust gasses are all going out of the house. In addition, I built a grate for the wood to sit on with some old pushrods from a car engine rebuild. It took about a month before the first pushrod had melted through and that is steel rather than aluminum. If steel goes that fast, think of how fast the aluminum will end up being gone. FWIW, even cast iron is eaten away by the fire so keep a good track of the thickness of the bottom of the firebox or you may eventually end up burning the house down even with a cast iron stove.

-- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works evevery time it is tried!

AmeriVent "B" vent double-walled stack pipe is for venting Domestic Gas Fired Appliances Only. They put big disclaimers stamped right onto the outer galvanized metal layer of all their pipes, and big warnings in all their literature. RTFM, guy, you got lucky in noticing (and recognizing) the problem. ;-)

Had the house burned down or someone died, they tried to warn you...

If you're putting up a stack for a wood or coal burning appliance or fireplace, you have to get a stack that's approved for the use. Usually the stack parts and firebox are approved as a system if it's for a pre-fabricated fireplace.

I've put in a few hundred feet of the stuff over the years... (~2 year stint as HVAC Mechanic, among other things.)

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Jack -

I have a steel wood stove - glass front and such.

I replaced the 1/4" steel roof in the stove that I burnt a hole through in about 10 years or so. There wasn't much left when I finally got to it.

The heat and temp are to high for Al - unless there is a massive heat sink that is really active.

Martin

Right.

I get up long before sunrise and often walk out and view my stove in the dark, walk around it and get to the kitchen.

The Red and Blue flames are really hot. The overall temp might be low, but the actual heat on the high temp brick is way up there.

Martin