Big Girtha Build Fins Part 8

Now that I've cut my balsa template master, here's another old school method to transfer that profile onto the balsa.

Hold the master on the balsa making sure the grain is running down the leading edge. Take a pin and poke holes down the fin edges using the master fin edge as a guide. Cut out the fin lining up your strait edge on the pin holes.

Here's another old school technique.

All four fins are pinned together for sanding and matching up the sides.

Before pinning together, the master template fin was edged with a black sharpie as a sanding depth guide. Don't worry about the black edge, the Sharpie won't soak very deep into the balsa and will be nearly sanded off in the next step.

Stack the three copies and then lay on the master making sure it's centered and probably a little inside the edges of the other three.

Pin all three together and sand with a block.

Keep an eye on the blackened edge. When you've sanded through about half of the black, the other edges of the copied fins should be the correct contour.

When all sides are sanded just into the black edges of the master, pull the pins and round just the leading edge of each fin. When papering fins, just the leading edge is rounded for rolling the paper covering over it.

Those pins holes are either filled with Carpenter's Wood Filler or covered over with the paper. You'll never see them on the finished model.