Sorry I'm just an -------. I'm no welding god but you get plenty pen on a piece butted up. 70,000 PSI tensile strength. For example if exhaust gases and turbo exerts 60 PSI inclusive leaves you with 69940 PSI of unused tensile strength. Believe it or not there is such a thing as over welding. At this point the piece is actully weaker.

 

doesnt the pressure raise exponentially when the gas expands?

 

PSI in general is has no where no the effect on cracking manifolds as some might think. The Main factor is the stress that is applied at the weld joints. Not to mention the extreme case of heat and vibrations that turbo manifolds go through. The stress is very often over looked and "bad welding" is commonly blamed for the cracking of manifolds. However it is a very good idea to to support a turbo with a brace or two. You can hold 100 psi of compressed air for months straight running through that pipe and it will not crack. As far as your welding scenario, that welder has plenty of power, just clean your material better then just using a wire brush. Good luck

 

And once again I'm not so wrong after all. I might not be 100% correct. I do think its a wise idea to use a die grinder to clean the weld area up first. Also drill a 1/6 - 1/8 inch hole at the end of the cracks to stop further craking.

 

http://www.canadiantire.ca/browse/pr...=1166507858156

would a welder like this be suitable for welding manifolds? its low setting is 50amps while high is 70 amps. it also says its good for welding 18 gauge steel to 1/8" thick steel, isnt shcedule 40 piping thicker then that?


the welder above only uses 1/16 and 5/64 rods, can i use 3/32 rods with it?

 

x2