Question about crack in wood stove

suitcase_sally · #1 03/12/10, 09:14 AM

I posted a few days ago about a hairline crack in the top of my Franklin stove. Can this be sealed with cement or anything? DH is concerned about carbon monoxide leaking out. The crack is truly a hairline crack - very tiny.

blooba · #2 03/12/10, 09:16 AM

I do beleive they have a JB Weld for high temps. Although that won't "fix" it just seals it. The problem is once there is a crack with the expanding and contracting when it heats and cools that the crack will grow.

suitcase_sally · #3 03/12/10, 10:11 AM

Rats! That was what I was afraid of.

Any opinions on wood stoves? I need something that I can place close to a wall. My space that needs heating is about 700 sq. ft.

Harry Chickpea · #4 03/12/10, 10:11 AM

CO won't leak out. The draft keeps a negative pressure on the interior of the stove, so air gets sucked IN.

ldc · #5 03/12/10, 10:12 AM

Also, use a CO2 monitor, then the alarm goes off if there's a mishap! ldc

suitcase_sally · #6 03/12/10, 10:13 AM

Thanks, Harry!

Wis Bang 2 · #7 03/12/10, 10:13 AM

Drilling the end of the crack may stop it from spreading it is a common thing to do to stop cracks in metal.

Drilling a few holes along the crack may give the HI Temp J B Weld a place to hold on as well instead of just speading a bead on top of the crack which may not hold/seal...

I believe cast iron can be brazed and can be welded if preheated by a welder who knows his stuff BUT arc welding, improperly done, will warp it.

tamsam · #8 03/12/10, 12:45 PM

If a few tiny leaks are a problem, Lord help us, as we use an old stove that is not air tight. I sealed it best I could with high temp sealer but I can still see the fire in a couple places when the lights are off. If the chimney draws it sucks all the gases out the chimney. We burn a lot of coal and no one has ever said they can smell it in the house. We have been using this old KING-O-HEAT heater for 5 years now with no problems. Wish I could find another one to put in storage just in case this one breaks or something. Sam

foxtrapper · #9 03/12/10, 01:34 PM

It can be welded. I know lots of folk think iron can't be welded, but it can, and quite easily.

suitcase_sally · #10 03/12/10, 04:54 PM

Hmm....I was a die maker in the auto industry before going into engineering. Whenever we had a die break (the cast iron "shoe", not the trim steels and such) we put what was called a "dutchman" on the casting to hold it together. I don't think that would work in this situation due to the cast iron being as thin as it is.

Iron (as in boiler plate) can be welded, but I don't recall ever welding cast iron.

I, too, have heard that it can be welded, but it takes a bit more expertise than what I have to do so.

FarmboyBill · #11 03/12/10, 06:10 PM

Remember, If the stove has been heated enough to crack, then the temper is gone out of the cast, and youll N E V E R be able to weld it. NEXT I dont think throwing crack inna stove will do u any good, the cops will smell it burning LOL

HermitJohn · #12 03/12/10, 06:17 PM

Quality cast iron can be welded. Cheap thin castings spider web. My opinion is that on stove best to braze it. There would be no advantage to welding on such an application.

Also hairline crack is no threat as to CO leakage.

**Cabin Fever** · #13 03/12/10, 06:17 PM

IMHO, it isn't worth your while trying to weld a cast iron Franklin stove. If it was a quality air-tight cast iron stove, maybe it would be. My recommendation would be to find yourself a good plate steel stove.

**highlands** · #14 03/12/10, 06:19 PM

Seems to me that it would be a very bad idea to have any derivative of cocaine in your wood stove... (Sorry, couldn't resist a crack about crack in a woodstove... *sign*

)

Seriously though, officially I have to advise you to toss it out and buy a new approved woodstove so that you can increase the Gross Domestic Product and consumer spending. Unofficially I patched our 40 year old wood furnace for decades without any problem. By the time I finally stopped using it it must have been more patch than cast iron - just kidding, the door was still mostly iron. I used a stove cement that setup hard when heated. It was made for that purpose.

I would also suggest having a carbon monoxide detector and adequate air intake for the stove, ideally dedicated to the stove.

Cheers

-Walter
Sugar Mountain Farm
Pastured Pigs, Sheep & Kids
in the mountains of Vermont
Read about our on-farm butcher shop project:
http://SugarMtnFarm.com/butchershop
http://SugarMtnFarm.com/csa

Old Vet · #15 03/12/10, 07:42 PM

The cast iron can be wielded or brazed. Use a nickel rod to weld with or use a bronze rod to braze with. Drill a hole at each end then get it hot and weld or braze it. I have done both numerous times and it always works for me.

foxtrapper · #16 03/12/10, 08:29 PM

Quote:

Originally Posted by suitcase_sally

I, too, have heard that it can be welded, but it takes a bit more expertise than what I have to do so.

No, it doesn't. If you can strike an arc, you can weld cast iron. Pick up the nomacast rod and do the job. It's made to weld dirty, rusty, cast iron without preparation.

Not a case of "I've heard", I weld cast iron, and this is the rod I prefer.

celticfalcon · #17 03/12/10, 09:46 PM

without a pic its hard to say.it can be welded if you know a good welder.it depends on how big the crack is.IMO over 3 in is not worth it as your integrety(sp) will be comprimised(sp again)
tom

soulsurvivor · #18 03/13/10, 07:52 AM

We have an old Warm Morning woodstove that we bought new 28 years ago. It's been of good service for us but we've had to give up on the repair of a major crack that showed up a few years ago in the bottom of the stove. We've had it repaired but it's still not a secure situation for inhome use. We have a friend that wants it to use in his dirt floor shop and we haven't yet decided to allow even that. We're considering selling it for scrap metal to be certain it's not improperly used and ends up burning down a building somewhere or gassing someone to death.

I guess what I'm trying to say is that as much as it hurts to give up an investment in a woodstove, safety has to come first and foremost with any decision that's made. There's no price that can be attached to a human life.

ET1 SS · #19 03/13/10, 08:12 AM

Cast iron is extremely hard to weld.

Back in the day, the prefered method of fixing cast iron was low-temp brazing.

However in the future as the cast iron heats and cools, it will expend and shrink again.

There is no way to get a braze joint to conform to that kind of expanding and contracting.

Drilling holes may releave some of the stress at those points.

I recommend a CO monitor, just to be safe. We have one.

This winter we bought a brand new cast-iron pot-belly coal stove directly from the manufacture.

It cost us $800, and it is rated at 200kBtu.

They are not horribly expensive.

I would say for you to simply buy a new one.

suitcase_sally · #20 03/13/10, 09:11 AM

Quote:

Originally Posted by soulsurvivor

There's no price that can be attached to a human life.

I know some people that aren't worth a nickle.