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Has annyone out there tried using JB weld to fix a crack in an Iron manifold?
Dont want to weld it and am too broke to buy headers for a y block right now.
My guess is that is welded nickel rod won't fix the crack, JB weld doesn't stand a chance. I have seen too many failed attempts at repairing manifolds. If it is a minor crack, you could live with it, unless you can smell it inside the vehicle. If you can smell it while in the vehicle, the vehicle may be unsafe to drive for any distance or frequently due to the possibility of carbon monoxide poisoning.
Cast Iron is a very fickle beast beast. No way JB weld would handle the heat. I'd say you should have an epoxy than can handle a minimum of 600 deg. I've welded and brazed cast iron quite a bit with sucess, but if you don't know what your doing sucess is slim to none. With cast iron prep is key. I would try to find a replacement manifold since you don't have the cash for headers.
i used Car Go Thermo Steel on a cracked exhaust manifold it says it will take heat up to 2400 degrees and i just followed instructions on package and it worked great i got it at oreillys for about 6 bucks it benn on there about a year with no problems
I have brazed several exhaust manifolds, prep is the key. First drill a hole at the ends of the crack to ease the stress and to stop the crack. I cut a valley with a grinder in the middle of the crack so there is a place for the weld pool. Then before I start welding I heat the manifold in the oven to 425-450 degrees then start brazing wile the manifold is still hot
instead of brass they make a cast iron rod but I have never used it.
i used Car Go Thermo Steel on a cracked exhaust manifold it says it will take heat up to 2400 degrees and i just followed instructions on package and it worked great i got it at oreillys for about 6 bucks it benn on there about a year with no problems
i second that...i got mine at Napa. Just make sure you prep the manifold according to directions.