You arent gonna **** anything up if you do one even pass the whole length of the primered area top to bottom. and if you do find it is dicked up its probably crappy body work to begin with. It gets the straightline scratches out of the primer. Everybody has different opinions on how to do...
I have heard good thinds about the martin hammers and dollies but i have only used snap on and matco. I personally like the matco. Invest in a rubber dolly for using with shrinking hammers so you dont dull the spiked face of a shrinking hammer
I have been in the autobody industry for 6 years now and have used norton and 3m sandpaper. Norton is alright in my opinion but 3m is my favorite. But , as others have said , you will pay higher price for the 3m. I finish mud work with 150 or 220 and finish block my primer with 320. Then i da...