Another round surface sanding technique I picked up when I was cutting opals is to use a hard back canvas belt of the approiate grit and just cup it on your hand. The piece being sanded will cause the belt to deflect into a curved surface. It gives you a very uniform smooth surface.

Thinking along this line, I decided it would be a good idea to cut some PVC pipe in half and use carpet tape to line the inside with the sand paper of choice. I made up several pieces. 1/2 through 2 1/2" pipe. My first use was the LE of a 4*60. I was so pleased with the results, the LE was uniform in curve and fair the entire length, then I noticed that I had really under cut the ribs with the edge of my sanding tubes. The idea was good, the aplicaton sucked. I found that half pipes didn't cut it becasue of the under cutting on the edges. However a set of 1/4 pipes is better. It will still under cut if you let it, but you see what is happining sooner.

By the way, a good source of long sand paper is sanding belts from the hardware store. I keep some on long pieces of wood, 80 through as fine as I can find. Great for cutting aileron V angles. and the long length prevents the hills and valleys.

One more sanding point, I keep a bunch of 280 through 600 grit popsicle sticks. I make them by spraying the back of a sheet of wet-or-dry and then packing the back of the sheet as full as I can with "Craft Sticks". Then take an Xacto knife and cut the sticks loose from the back of the paper. The 280 and 320 grit eats CA glue, but is fine enough that it doesn't do much to the balsa. Light pressure and it cuts the CA very well.

Don