I wonder how to sand filler on concave surface.As on the wheelarcs on a 68 Cutlass.I never get a result I am satisfied with.
Hope somebody will share their knowledge.

 

You can get that foam pipe insulation in various sizes(Outside diameters) Wrap it in sandpaper. The insulation is flexable so you can bend it as desired. also you can cut it in various lengths depending on the result desired. This works well on those 68-69 wheel archs

 

You can also use a piece of a swimming pool 'Noodle'. They are sometimes larger in diameter and can work great for an inside radius. There are also several very good tutorial videos on Youtube about sanding in tough spots.

 

There are various cardboard tubes available free, one I can think of is the tube in a used up masking paper roll. Also ,when making a first cut for shape as mentioned in previous post wrap the tube with 36 or 40 grit (sticky back) and cut the filler when it is green (semi hard). Once you get the shape the rest will be easier .

 

I have soft foam sanding blocks to shape corners. For long countour surfaces I have foam blocks with rods inside of them to adjust the stiffness. Being creative is all part of it. I have been doing body work for 10 years and have made a bunch of my own tools.

 

^^^This!

The fundamental rule is that the sanding block needs to match the curvature of the surface being sanded. You can buy a wide variety of contoured foam sanding blocks in various stiffnesses, or you can find materials to make your own. There is no right or wrong, do what works.

 

These blocks are nice and work really well for finish sanding like over contoured 1/4 panels etc etc. I have 2 of them and well worth the money. http://www.eastwood.com/27-inch-adju...le-sander.html