Welding sch10 pipe (manifold

[turbotigdan]

Hey guys

Made a turbo manifold for a friend from Sch10 tubing, however its prone to cracking on the welds after some use. Its cracked again so im re welding it for him. Just wondering what sort of current/wire speed would be advised to used on this as i think the problem might be its not penertrating enough as its quite thick metal.

 

[Wozzaaah]

Might be an idea to post some pics of the manifold showing where it's cracked, it could be more of a design issue rather than poor welding.
Lots of good manifold makers on here who will know exactly what's wrong.