New Way Letter - Go Build, Part 2, Cleaning Up The Letter Fins

The letter fins are cut from 3/32" thick plywood.

The edges are slightly laser charred. The flat faces were sanded with 400 grit on a block to remove the ash.
 

On the left - 

is a before and after sanding the fin edge. 

On the right - 

The inside tighter curves were cleaned up using small half round diamond files.

The laser edges are cut with a slight "wedge" cut.

The picture shows the wedge cut sanded down about half way. You can see the angle of the laser cut.

This sanding is most important on the root edges so the fin sits squarely onto the body tube.

Finish up by just kissing down any rough edges with a light pass of 400 grit.

You don't have to put a rounded edge on the fins, just knock off any roughness.