Welding cast iron

[mmm240]

I recently sourced a turbo manifold for my 22re build and it has a crack, small and not all the way through, but it's a really hard part to find so I'd like to salvage it. My buddy who knows a bit more about welding than I tells me it's a real pain. I have a mig welder and I'm looking for tips on how to get this done.

[Razi]

I had my SR/KA hybrid manifold welded together by a member on here, Motoman.
I heard he torched it with a propane torch or something until it's red hot, then he welds it.

I heard similar things from people who modify 240sx steering knuckles.

[mmm240]

Thanks for the tip. I wonder if I can get it hot enough with propane.

[AZhitman]

Not easy. Everyone I've talked to says it'll eventually crack again.

http://www.buzzle.com/articles/cast-iro ... -iron.html
http://www.weldingtipsandtricks.com/wel ... -iron.html

[Oatmealman]

Get it up to about 500 hundred degrees farenheit weld an inch or so and keep it as close to 500 as possible.Then it has to cool for HOURS.Wrap it in as many welding blankets as you can.Ive seen pumpkins hold heat all night wrapped in about 20 welding blankets.

Alot of wheeler guys weld things to cast iron and it handles the abuse just fine(i.e,full throttle assaults from 600hp v8s lockers front and rear and 46's on a rock wall.)

its all about using an extremely high nickel content rod(tig best way to go for this sort of thing imo),preheating,and cooling extremely slow.Do those few things and it should outlast the vehicle by far.Id honestly pay a welder to do it(they'll b**** and moan because of the labor involved) but tell them to shove it up their a** and just do it.

[elwesso]

We do it all the time at work, we have cast spring seats that we weld to spring pads, as well as other things.. I can ask the welding guy how we do it at work, because we do all MIG welding.

[PapaSmurf2k3]

I've done it a few times with good results. As stated above, get that mother HOT. I used an Oxy/Acetalyne (sp?) torch, followed by MIG welding. I had a 110v welder, so I turned the heat all the way up on it. None of the ones I've done have cracked in ~6 or 7 years.

[mmm240]

Good stuff guys. Thanks again

[AZhitman]

If you don't mind sending it to AZ and back, Jason (rotorimp) said he could do it... I'm sure he wouldn't charge much.