March 12, 2017
I worked in my Dads body shop from about 1975 to 1982 and nothing was block sanded back then. We used a heavy rad-oxide lacquer based primer and just sanded it with a piece of folded sandpaper in the palm of the hand. Back then paint went with lots of "orange-peel and no clear - so it wasn't as shiny and therefore didn't show as much. People where less picky then too because the paint that came out of the factory wasn't as nice as it is now.
But now-a-day, panels are expected to be laser straight and shiny, so we block sand high-build primer - with long blocks - to ensure everything is straight. It makes a huge difference, but it's also a huge undertaking.
Next weekend I'll finish up this first round of blcok sanding, address any larger imperfections, then spray a final coat of high build. This final layer will be final sanded to 400 wet for sealer and paint. Which is to say we might have this thing in paint sometime in April... (no promises of course! ;))