While this is not exactly what I used, it is a good analogy.
For a beginner this would be some
usable fiberglass.
And this would be a
workable resin.
- Cut the fiberglass into about 2" wide strips that are a bit longer than the fins.
- Mix up the finishing resin and use a small brush to apply it to the inside of the fin. Make it rather wet.
- Lay the strips of glass in a 1/4" overlapping pattern inside the fin and sort of pat them down to sit in the resin. You want the glass to soak up a fair amount of the resin. You might have to paint more on top of the glass to ensure it is wet.
- Insert a 12" latex balloon and blow it up. You will likely get epozy on yor nose. I'm looking for a way to fill the balloon with a hose.
- Let it cure a couple of hours and pop the balloon.
- Trim the edges for appearance and you have a nice stiff tube.
This also works to beef up couplers.