New Way Lunar Jumper Build, Part 5, Balsa Fin Filling

There are three extra small forward fins. 

Only three are needed for the build.

After filling with CWF and sanding to surface - 

The outside edges of the fins were masked with a strip of tape for the filler/primer sprays.

All the fins and tubes were taped down to scrap cardboard for the filler/primer spraying.

After drying, the pieces were lifted and flipped over to spray the other side.

The long BT-50 main airframe tube was sprayed with filler/primer.

The paper towel stuffed in the end blocks any paint from getting inside the tube.
 

The same tube after sanding with 400 grit. You can see the gray primer left in the seam after what was left from the earlier CWF pass.

I do a two step fill - 

1. Brush on one coat of thinned Carpenter's Wood Filler, let dry and sand to surface. 

The surfaces are not yet sealed. CWF is water based.

2. A fairly heavy spray of filler/primer. Let dry and sand to surface using 400 grit. The filler/primer soaks in a bit and helps seal the surfaces.

You should now be ready for color coats.