The Stovebolt Site Forums The Shop Area General Truck Talk ehaust manifold

I have been working on a Fxxx for my father. The ehaust manifold has broken. I know it will be a major pain to replace is there any way that jb weld will hold this together? Thanks,

go to home depot or where-ever and get some epoxy putty,, if you can get to the crack or brk this will probably do, I use it all the time being that I am not a welder,,have my tail pipe put back together with this stuff and it is still holding, this was over 2 yrs ago,, I use it all the time, just a putty type of clay,, peel off what you need, rub it together , put it on what ever leaks or needs sealing, or broken, it gets hard in about 5 min,, should work,, let me know,,,Fred

Cast iron exhaust manifold can be repaired by broadcast heating the entire unit and brazing with an acetylene torch. An experienced welder at a local weld shop can do this repair with lasting results if it is done properly. Depending on the year and displacement of the motor you may be able to find an OEM replacement and/or one from a scrap yard. If you plan to have it brazed, it will have to be removed from the block for prep and heating. Good luck with your FXXX repairs.

Welding cast iron isn't that difficult. Use 99% nickel rod. Preheating is better but I have done it without. Dirty cast iron seems best welded with a stick welder. Clean can be welded with tig. It isn't enough to shine it up, grind the crack down to clean metal. You will have to grind a lot as the rusty and contaminated layer is thick on an exhaust manifold. Vee the parts at the weld but don't vee to deep as the iron burns through easily. I have found that you need to keep the arc very short. It isn't at all like welding mild steel.

Just went thru this last night.... I was going to replace the manifold gasket as she wasn't running right... found the exhaust manifold broken... pulled it off and used a tig welder BUT when we bolted it back on it didn't seat tight. Getting it to sit flat while you weld it is key. Another option is to tack it before you unbolt it.

....Meanwhile, I think I found a replacement.