You always have to be careful sand blasting sheet metal.

I would use sand blasting on sheet metal as a last resort, and or for the really hard to get to stuff. The big flat areas that are easy to get to are also easy to warp are best sanded with a sander by hand, not sand blasted. If after sanding you have small spots of rust blast them carefully.

I've been really impressed with soda blasting for sheet metal, removes everything but the rust. Faster, better, and easier, but not any cheaper than chemical striper.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-