# Fixing crack in cast iron



## blazen (Oct 14, 2008)

Hello,  

     I Just got a 1986 defiant encore vermont casting handed down from my mom who fortuanately got a jotul oslo, but unfortuanately for me the defiant has a crack in the top lid and needs cat replacement.  Is there a way to seal this crack?  Also upon dismantleing I noticed there was some sort of putty around the seams on the lid .  What is it and does this need to be reapllied?

Also, of coarse the cat and refractory bed need to be replaced.  Anyone know the best place to acguire these?  Any help much appreciated. Thanks-Alex


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## Jags (Oct 14, 2008)

Cast Iron can be repaired, but it should be done by someone that is familiar with it.  It requires area heating and blah, blah, blah.  Find someone that knows cast iron.

The putty would more than likely be stove cement.  A common material for sealing up seams in cast iron stoves.  This can be purchased at most hardware stores as well as some of the big box stores.

Edit: and yes, it needs to be reapplied.

For the cat - got no idea.  Someone should be along with that info.


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## humpin iron (Oct 14, 2008)

Replace the cast panel with a new one.  Stove and gasket cement can be bought in chaulk tubes.  Google vermont castings parts to find a source


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## madrone (Oct 14, 2008)

Unless you know a welder, it's probably cheaper and better long term to replace it. It can be arc welded with a nickel rod, but that's still not always so successful. Most cast iron repairs are brazed, but the brazing has a fairly low melting point, and I suspect it'd be in danger of failing in an overfire. Any other cement style repair will fail, as the cast iron may continue to crack from expansion and contraction.


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## 94ranger55 (Oct 14, 2008)

ur cast iron needs to be brazed with brass or bronze.... cast iron can not be welded it must be brazed


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## bfunk13 (Oct 15, 2008)

I have welded plenty of cast iron.
Grind a bevel on both sides of crack.
Leaving about a 1/8" land. PREHEAT the iron hot enough that you cant 
leave your hand on it, weld with mig or stick welder. POSTHEAT the piece
so it dosent cool too fast. A good way if possible is burry the piece in sand, 
to slow down the cooling process. Once the piece is able to be handled grind weld as necessary. 
They make a series of crayons that melt at different temps. I know there is one for repairing cast iron.
Heat the piece until the crayon tip will melt if touched to the iron.
Its a tricky repair, but it can be done.
Brad


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## whiskeyrichard (Oct 15, 2008)

yeah, you can weld on it. I have not done it, but we just learned about it in welding class.

The problem, as I understand it is, cast iron is very brittle. The process of welding a joint puts a  lot of stress on the metal around it, because the weld pulls the joint together. Cast iron is so brittle that this pulling together at the weld joint will cause splits elsewhere in the part. 

I was told that when you weld on it, you have the peen the weld. This is in an effort to push the weld down into the joint which will relieve some stress on the surrounding metal.

Me personally. I would try to weld on it, but I'd have the money set aside to buy a new part in case I wrecked it while welding on it.

Russ


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## SnaykeByte (Oct 15, 2008)

I can weld it with a TIG machine, I do it almost every day as we repair heads and manifolds. PM me and we'll talk.


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## Elderthewelder (Oct 15, 2008)

94ranger55 said:
			
		

> ur cast iron needs to be brazed with brass or bronze.... cast iron can not be welded it must be brazed



not true, it can be welded. I have done it with a TIG as well. Grind it out, pre heat it and use a nickel based rod ( Inconel 82 works well) if you have a way to cool it down slowly that is even better

Like someone else said, if you braze it, the repair well fail overtime from the heat of your stove

There are shops that specialise in welding cast, check your local yellow pages


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## woodzilla (Oct 15, 2008)

preheat cast iron to 400 deg. Weld with 55 % nickel rod. Cool slowly. Usually immerse part or cover in sand and wait,wait,wait. Contact local portable welding supply for compAny names of portable welders in area if needed.


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## madrone (Oct 15, 2008)

I'm wondering how much a lid costs. Since it was free, it seems reasonable to just replace it and eliminate all possibility of failure, as long as it's not outrageously expensive. If a good shop you can trust can weld it for significantly less that seems alright, but if there's not a huge difference, I'd let them melt the old one down.


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## polaris (Oct 15, 2008)

These folks are right cast is/has been welded daily by mig,tig and stick(even JB weld). Think engine blocks. I wouldn't be one bit afraid to have a competent welder repair it. It won't be as pretty but chances are you will be fine.


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## blazen (Oct 15, 2008)

Thanks for all the info.  I tried to get a price on a new lid but sales rep said they are unavailable.  I will find a local that specializes in welding cast.  By the way can I run this stove with out the cat? Thaks-Alex


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## humpin iron (Oct 15, 2008)

you should not run a cat encore w/o the cat.  goes from one of the most efficent stoves .09 grams to a total dog 60 grams plus.  heat transfer also drops


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