Noticed everyone sanding dry body filler with 80 grit

I was at a shop in Dayton last week watching a guy take 80 grit to fresh filler on a quarter panel. He was making deep scratches that took forever to feather out. My old mentor always said to start with 36 or 40 grit for the rough shape, then jump to 120 for the final passes. It saves like 20 minutes per panel and you don't end up with those swirl marks that show through paint. Has anyone else seen shops skip the coarse grit and run into issues with pinholes or sand scratches later?

2 comments

2 Comments

olivia_harris1917d ago

@blake322 I agree 80 grit works well if you don

blake32217d ago

Whoa, I gotta push back on that a bit. Starting with 36 or 40 grit on fresh filler sounds like you are grinding into the metal before you even get the shape right. When I learned bodywork, the trick was always to use 80 grit because it cuts fast enough to shape but leaves a scratch pattern you can actually cover with the next grit. Going that coarse first usually means you spend more time trying to get the deep gouges out, and you risk thinning the filler in spots where you need thickness for the curve.