Cracked cast iron manifold

[crushnut]

How possible is it to weld shut a crack on a cast iron exhuast manifold?

I have heard that the whole peice would need to be pre-heated and stick welded. Anyone know anything about this? Can I use my wirefeed on it?

I know normally you dont want to weld on cast iron becasue it weakens it but im just looking to seal the crack and illiminate the noise.

If you TIG weld it then it doesnt need to be pre-heated.

 

[WORTH]

Hey Crushnut, can you stop answering before he asks the question, your confusing me........

 

[crushnut]

Hey Crushnut, can you stop answering before he asks the question, your confusing me........

Its not me, Stangnet is being screwy. I replyed after he asked the question, but it put mine above his

Your doing it too

 

[67coupe351w]

How possible is it to weld shut a crack on a cast iron exhuast manifold?

I have heard that the whole peice would need to be pre-heated and stick welded. Anyone know anything about this? Can I use my wirefeed on it?

I know normally you dont want to weld on cast iron becasue it weakens it but im just looking to seal the crack and illiminate the noise.

 

[crushnut]

Or you could try this stuff.....

http://www.prp-porstore.com/page/por15/PROD/Fillers/FS

Dont know how well it works though

 

[LMan]

any reason you can't JB Weld it? The intake doesn't see extremely high temperatures, and IIRC JB Weld has a ~600F upper limit.

 

[crushnut]

any reason you can't JB Weld it? The intake doesn't see extremely high temperatures, and IIRC JB Weld has a ~600F upper limit.

I beleive he was talking about an exhaust manifold, not intake manifold

 

[LMan]

ahhh, you are right - old age and bad eyesight

hmmm.....but sounds like an opportunity for headers to me!

 

[67coupe351w]

Yeah headers would be cool if I felt like wasting money on a vehicle other than my mustang

What im wondering though, is will my wire feeder actually work. I was told the bead would just roll off the cast iron as I tried to weld unless it was preheated and stick welded.

 

[WORTH]

Yeah headers would be cool if I felt like wasting money on a vehicle other than my mustang

What im wondering though, is will my wire feeder actually work. I was told the bead would just roll off the cast iron as I tried to weld unless it was preheated and stick welded.

hit it with a bead and see what happens, I'm pretty sure you can buy cast wire for the mig.

 

[pabear89]

I have patched some by welding.
But it holds better If you stitch weld,
you don't want to get the cast to hot
or it becomes brittle.

PB

 

[351LX]

I have fixed exhaust manifolds and heads using a nickel based welding rod for my AC arc welder.I didn't preheat but I made small beads about an inch long and waited a minute or so to let it cool before I put the next one down.If cast iron gets too hot in one spot it will crack as it tries to expand so if you don't preheat you have to go slow.

 

[1320stang]

I took a cast manifold to a boat shop where they repaired it. It was cracked 3/4 the way around. It was done by pre-heating with a torch to a cherry red, then hit with the nickel based rod with an arc welder. Aparently boats need a lot of welding done on cast iron.

 

[hdgapeach]

Unless you have the equipment and the technique down, I'd call around for a welding shop to do it. The problem that I've had in the past welding cast is controlling the cooling. If it cools too fast, it's gonna crack and you'll be right back where you started from.