I dont have access to a Aluminum welder, but I do have one for steel. Would I be ok to use steel as opposed to aluminum? This is not going to be drain back. Its going to be open vented.

 

Due to the amount of moisture id say it would rust on the inside
but yes you can make one out of steel

 

Doesn't a catch can collect oil residue? Doesn't oil help steel resist rust? I can't see it really being a problem.

 

sure u can, as long as the contaminated oil doesnt make its way back into the motor .. oil will seal it up but IT WILL eventualy RUST due to the condensation.. try it and let us know how you make out!!!

 

rust shouldnt matter since ur not draining back. but if your worried about it just use stainless, u could weld that and it wont rust.

 

I used a section of 3" stainless tube, has been working fine for me. Capped the bottom and used a 1.5" vent on the top

 

Make it out of stainless. Most people make them out of aluminum for weight savings and bling, I have made one out of stainless and they work fine

 

I have done a mild steel catch can out of sheet and a coolant reservoir out of tubing. Two years, no rust issues. Even cracked them open to check. It was more of an experiment than anything, but it worked out well.