I don't know about welded. But I did some research and the JB Weld product seems too good to be true. It states in has been used in cylinder heads! Impervious to oil, gasoline, water, etc. and can withstand vibration, pressure, etc. I am going this route and see how it works. This product has been around for quite some time from what I understand......

An ounce of prevention provides a pound of cure!