Shaping Estes Nike Smoke Fins, Part 4, Primer Filler

On a shaped fin like this one, each step helps define the sanded edge taper.
The first shaping step is the balsa fin shaping with 220 grit on a block.
The second step is the sanding of the CWF. The  buildup of the CWF on the two raised "ridges" helps sharpen the line.
The third step in shaping is the Duplicolor Primer/Filler.
Here the fin has been sprayed and is ready for fine sanding with 400 grit on a block.

Most of the primer/filler is sanded off the leading and trailing edge tapers. Try to keep the block away from the central raised ridges.
You will sand to the ridges anyway, just be aware of where the line is and try to leave the primer/filler on the line.

After the sides are done, the flat center face is sanded.

Notice the gray filler is left at just the top of the taper ridges. Sand the lines straight using the remaining paint as a visual guideline. Use the paint to (finally) define the ridge line.

You probably won't get it on the first try. Cut extra fins and practice on the scrap balsa. Then - work on the fins supplied in the kit.

As I said in the first post, most builders won't take the time to taper the fins. If you choose to round the leading and trailing edges you might want to cut new fins from 3/32" thick balsa. The fins in the Estes kit are 1/8" thick, a bit clunky looking (without tapering) on a "scale" model.