Block sanding?
 

With a solid block sander, how do I get around those curvey areas of a 911 like around where the front fender meats the hood, the upward curve part?

When I put on a contrasting coat of paint to sand off (finding highs and lows), do I need to sand all of it off?

Thanks,

David

There are flexible foam blocks. I have some that are two-sided, each side being of a different durometer of foam.

You don't need to completely sand-off a guide coat; it should be a light mist anyway.

Thanks Tom for the help.

Be patient. The complex curves on a 911 are not the easiest to get perfect.

I made my own sanding blocks. The white or blue dense foam that computers are packed in work great. Cut it thick or thin to change stiffness. Make it whatever shape you want and then use 3m spray adhesive to mount the paper. Self adhesive discs also fit well.

You will want to sand the curves in an "X" pattern to the countour. Matching long diagonal strokes work the best.

Many pros use a paint stick with paper wrapped around. They slide the stick on an angle to keep the edges from cutting grooves.

When you get down to the 400 stage as a final prep for painting, it's not so bad to use the heel of your hand in complex double contour areas. People don't like to see you use your hands because often times you can leave "fingers" in your work and the paint will look rippley. But, it can be done.

You can many times tell a machine prepped job by the images in the paint. As I said, though, 400 doesn't cut agressively, and if you are aware of the pitfalls of using your hand for sanding, you won't hurt the job, IMO.

When using any block, hard or soft foam, rubber or a section of radiator hose for inside contours, you must avoid working the pad in the same direction of the edges. They will dig in. You have to slide them all a bit on the bias to keep thngs right. It helps to change directions and criss cross your work.

I still carefully hand sand reverse fender flares on the front watching the lip all the while so I don't take all the primer off.