Originally posted by ALBERT:
You can also do a light mist with a rattle can the area to be sanded with a highlighted colour this will show up any low spots when you block sand..
I was doing that and found it to clog the paper quickly and I had to wait before sanding. Then I learned about "3M dri-guide coat" which is basically like copier toner that you smear on with a sponge applicator. It showed exactly where to sand and where it was perfect. Never again will I block without using it.
Curt B.
