Originally Posted by timothale
My old neighbor in Calif used to build circle track cars and I always had him do my critical welds. He said some of the made in China sandpaper will contaminiate the metal because of the adhesive they use. He always cleaned the parts with acetone as the last step.
Never had a problem using the pad's,And never had to use Acetone,And never had to pre heat any of the Alum I did,
I did ''ALL'' the Alum work,For one of the biggest (if not the biggest,,I think he is)offshore boat company in the world for about 10 years before I became disabled.
He also own's a bunch of shipyard's that only build's his boat's.
300 foot supply boat's and Ice breaker's..