Welding Tips and Tricks

I've done several jobs welding cast iron manifolds for different vehicles and I was wondering how other welders fill the cracks? I use nickel-copper rods and wondering if tig welding would be a better method of welding cast iron. Setting up some test for verifying which welds holds better would be very time consuming and I just don't have the time. If a manifold is already cracked then it's gone through many cycles of heating and cooling. Welding it is only going to help extend it's life and it can't be expected to be like new again. That being said, I wonder what kind of estimate I can give the customer as to how long the weld might hold before the manifold cracks again.

How successful were your other cast iron repairs? I have welded cast iron with a mig, tig , and stick and haven't found one to be better than the other. It is all in the prep and procedure. There are many variables to consider when welding cast iron. Following the fundamental rules when welding cast will greatly increase your chances of success.
As far as giving an estimate on how long the repair will last, I wouldn't recommend it. You will be setting yourself up for a lot of headaches. I tell my customers that I can't give them a guarantee and that given the physical characteristics of cast iron it is impossible to predict how long a repair will last. Hope this helps. Good luck.