[nsb29]

Originally Posted by lupo

I checked out the video and it was very interesting. Unfortunately sand swell marks always appear later after the car's been painted. I had a roof job where the roof had been sandblasted and warped. I let my buddy ,who's a bodyman for 50 years fix the roof. He used filler common 80 grit then epoxy, and a year later the entire roof was all scratches. if I were to use that tool with the 40 grit wheel I would definitely follow it up with 220/320 before priming. If it takes off paint that aggressively it has to be a bit on the Rough Side they did use the terminology 40 Grit
The one sure thing about bodywork is you always learn things the hard way

Scratches in metal is not the same as scratches in bondo! metal doesn’t shrinks like filler so if you bury bondo scratches with epoxy and 2k primers there going to come back and haunt you not so much with metal if you want to do it right always use slick-sand for your high build primer over epoxy slick-sand has zero shrinkage even over 40 grit scratches