This article appeared in an old newsletter, but since there are so many new members in the club, I thought it would be worthwhile to repeat it again.
You know how those balsa fins break so easily after the first flight. You put so much work into a model rocket only to have those balsa fins to break on the first landing. Well after you follow the below procedures, you won't have another balsa fin break. It may snap off the tube, but the fin itself won't break. The 2 ounce fiberglass you need to do this can be bought at Hobbies N Stuff for $6.00 for one square yard. You'll find this is an easy way to fiberglass fins without the need to sand after the epoxy has hardened.
Here's the steps:
1. Lay a sheet of wax paper down on your work table that is big enough to
hold all the fins you want to fiberglass.
2. After you remove the fins from the balsa card stock, place the fins on the wax paper.
3. Lay one sheet of 2oz fiberglass over all of the fins.
4. Pour 20 minute Finish Cure epoxy over the fiberglass. (Hobbies N Stuff has this epoxy too!)
5. Use a piece of plastic, like an old credit card, to evenly spread the epoxy over all of the fiberglass covering the fins.
6. Lay another piece of wax paper over all of the fiberglass.
7. Use the piece of plastic to smooth out any trapped air bubbles between the fiberglass and the wax paper.
8. Lay a book or any other heavy smooth surface object over the wax paper to weigh down the curing process of the epoxy.
9. When the epoxy has cured 24 hours, peel away the wax paper on both sides of the fins.
10. Cut the excess fiberglass from the fins, sand as necessary, and repeat the steps for the other side of the fins.