Galvanized pipe on a wood stove?

[BioHazard]

Please help me settle an arguement here. Somebody tell my ******* friend that 6" galvanized pipe (ductwork, single wall) is NOT meant for a wood stove!

He will be using single wall pipe either way, but I'm pretty sure there's a reason stove pipe comes painted BLACK. As I understand it the fumes from heated zinc are poisonous, and have always been warned never to weld on galvanized metal for this reason. I don't know the exact temperature, but I would assume that wood stove pipe gets pretty damn hot. Probably just fine for your efficient water heater (his arguement) but a wood stove is a different animal.

Am I wrong?

 

[RAYJAY]

I have Galvanized. pipe on my stoker for the last 7 years with no problems

the black pipe will rust out really fast

Jeff

 

[walrus]

This has been discussed many times on here. I've used galvanized on wood stoves before. I'm sure there are some fumes that come off it the first time it gets hot, after that I'm not so sure. I'm pretty sure the black pipe is used for looks and their are fumes that come off that the first time it gets hot also.

 

[burleymike]

Most common air duct pipe is 26ga while stove pipe starts at 24ga some is 22. 26ga is too light for a stove. In a chimney fire it can burn through not to mention the life will be shorter, stove pipe rusts from the inside out. When you have a hot fire the flu temps will be high enough that the zinc near the stove will burn off. Once it has burned off it is no longer harmful to anybody. Those zinc fumes can give you metal fume fever. From what I know of it, it is very miserable but not permanent.

The best stove pipe has locking ends that fit very snugly together so if you have a chimney fire and close the dampers on the stove you can keep more air out of the chimney to help starve the fire. Tight fitting pipe also reduces smoke leakage from down drafts etc.

 

[tncatadjuster]

I went to a local semi-truck supply and used exhaust pipe, that was about 6 years ago.

 

[WVBrady]

I don't have any first hand experience, but I found this in a search:

"The Sweep I apprenticed with taught me that, while galvanized pipe was OK for gas exhaust, it could not be used for woodstove connector pipe, which gets much hotter. I passed that warning on to all my trainees over the years, so the discovery of galvanized pipe on the woodstove was a red flag for our Sweep."

http://hearth.com/econtent/index.php/wiki/Galvanized_stove_pipe_-_NO/

 

[NUTTSGT]

I have galvanized on mine, from the wood stove to where it goes out the block wall into the chimney. I have never had a problem with it. I bought mine from somebody that does commercial work, it is a heavy guage, probably heavier than the readily available black pipe.

 

[BioHazard]

Most common air duct pipe is 26ga while stove pipe starts at 24ga some is 22. 26ga is too light for a stove.

That will definately be part of his problem...I know it's DUCT WORK, not EXHAUST PIPE...because he bought it at Home Depot, and they don't sell ANYTHING for wood stoves/fireplaces.

It's not going in his living room, but still, we're going to have to have a talk...

 

[nate379]

You sure? They sell all sorts of wood stove stuff at the Lowe's and Home Deports around this neck of the woods. I think they sell stoves even.

 

[BioHazard]

You sure? They sell all sorts of wood stove stuff at the Lowe's and Home Deports around this neck of the woods. I think they sell stoves even.

Nope, not around here. I believe the codes for installing a new stove are very unfriendly and expensive. I had to go to a small hardware store out in the country to even find 6" single wall black pipe!

 

[Mattlt]

Ask your insurance agent. If the stove causes a fire, and they see something they don't like... Guess what? They won't pay.

 

[Jim51]

I used to weld galvanized material all the time. First indication your head is a little too close the the fumes is a sweet metallic taste in your mouth. Prolonged exposure can do some serious damage. There are a couple of reasons why it should never be used around a wood stove and toxicity is only one of them. The zinc will burn off the inside of the pipes long before the outside even starts to discolour. Wood smoke and cresote are fairly corrosive and will eat out your pipes from the inside. Throw a chimney fire into the equation and you have a very serious problem. Flue pressures and temperatures will literally blow your pipes apart and burn your house down. One more reason to always add a few screws to hold your black stove pipe sections together.

 

[nate379]

Never mind that he is using galvanized pipe, but why is he using single wall pipe even? That isn't allowed per code around here and they are quite lax with codes, so I can only imagine it would apply to 99 of 100 locations.

I suppose in a shop not the end of the world on single wall, but better be careful about touching it.

Many years ago I was working in my Dad's shop and kept smelling burning wood. Well after a few hours I found out what it was. Someone (I think my Dad... but he claimed it was us) had leaned a shovel between the chimney and stove and the handle was against the stove pipe.

 

[jklingel]

The white smoke you see when you heat galvanized steel too hot is full of zinc oxide. As mentioned, it can get you sick, to the point of death. Other than that, it ain't too bad. I'm sure it works as a stove pipe as long as the stove is not too hot, but what if? When I have to weld on galvanized, it is outside, with a big fan on it, and I only weld as long as I can hold my breath. Never had zinc oxide poisoning, so I don't know what it feels like. The thought of pre-mature death does not rest well w/ me, though. I'd rather get eaten by a grizzly I wounded and am running down. Choices.

 

[Chevylove81]

I have a small stove with galvanized pipe zinc burnt off first time I fired it up going on 3 years now no problems yet

 

[Jazz1]

Ask your insurance agent. If the stove causes a fire, and they see something they don't like... Guess what? They won't pay.

Right there. There is a reason its called stove pipe.

 

[fireguy]

I could not find black when I installed my wood stove in the garage. I used galvanized. I built a good fire in the stove. I opened the overhead door, and the man door by the stove. I went in the house and when the stove burned off the galvanized, I did it again. That worked for several years, before the pipe rusted out. Then I bought black stove pipe. It has lasted for at least 10 years.

A couple of times, I could not get the pipe to snap together. I bought 3 large hose clamps and used a socket to tighten the hose clamps. Then I used self-tapping screws to hold the pipe together.

 

[Bretny]

Nice..bringing back a 8yr old thread.

Real stove pipe is one piece with out a seam that you can take appart. I wouldnt risk useing anything but the right stuff.

You havent found stove pipe because your going to tje wrong stores. A wood stove store will have the correct pipe and fittings.

 

[danski0224]

Menards around here has so-called "black stove pipe".

It's just painted black. Cheapo 24 gauge stuff, no different from the galvanized counterpart. Nothing special.

It isn't hot rolled heavy gauge pipe that is normally associated with the phrase "black pipe".

Maybe the paint is something special- got me on that one.

 

[6768rogues]

I use a heavy gauge black pipe and I put a few screws through the seam just in case even though I never saw a heavy gauge pipe come apart. However, I have seen thin galvanized pipe on a wood stove where it came apart at its seam. It was a major problem when it gave out with a fire going, too hot to touch and still smoking. We had to discharge a fire extinguisher into the wood burner to put out the fire, and ventilate the house to get the smoke out.

 

[readhead]

Galvanized stove pipe was all that was available for years until black painted "designer" pipe became popular in the seventies. After all who would want galvanized pipe on the new harvest gold cone shaped fireplace in the new family room.