I have a set of stainless marine exhaust manifolds that I need to repair a few holes on one of them

I was guessing they were stainless steel
but they feel too light in weight to be stainless

they feel more like aluminum

does anyone on here know for sure what material theyre made of ?

aluminum...

Send them back to Stainless they will fix them if they can be fixed.

cast aluminum,powder coated.