Just a quick question...when I block out my E.C. panels with guide coat and I expose just small spots of metal, before I sand away all the guide coat...am I suppost to stop an reapply more primer and block until literaly no metal is exposed, even though the areas feel straight? I am using 150 grit an a long board... Thanks

7T2SS...

Let's say that if you would stop sanding when you break through to the metal and then apply more primer on the whole panel and you would then come back and sand off half of the last primer coats thickness then the spots should not pop up again (in theory anyway). I don't do body work everyday but I had some spots pop up on my car (high spots) when block sanding and I would slowly start to see them appear through the thin primer coat layer that was still on top of it. I would then stop sanding and lightly tap the high spot back down with my body hammer. I then came back and shot the whole panel with primer and did the block sanding again. If I had it tapped down enough it would not re-appear but if it was not tapped down enough it would start showing up again and I would then give it another tap or two. I finally figured out how much force to hit the spot with the hammer so that I didn't have to come back with any body filler from knocking it in too far the first time or doing more damage than good.
I also did the reverse on low spots where the guide coat was not removed and tap the spot out from the backside to bring it up (providing I could get in behind the spot).
Jim