Red River Rocketry Starliner DST, Part 7, Fin Shaping and Gluing

The instruction say to sand the fins to an airfoil shape.
I couldn't see any reason for this, a high drag model with an efficient shaped fin.
The fins are small and it would be hard to shape an airfoil.





I simply sanded the leading and trailing edges round.

Here the fin is set next to it's glue line on the shroud.
A thin strip of masking tape was set on the line before spraying some primer.


After spraying and sanding down the primer you can see where the engine mount glue has slightly puckered in the body tube.

I didn't use much glue inside the tube before sliding in the mount. I was relying on outside fillets for strength.
I could be wrong, but this might be a recycled paper body tube. You'd never run into this problem years ago with the older brown tubes.

TIP: To hide the glue tab overlap on the shroud, glue a fin beside the stepped tab joint, not half on - half off. This also means the other two fins will be glued beside and just to the left of their position lines.

On the left is one of the two fins glued beside the printed lines.
On the right is the fin being set in the side of the overlap joint.
Glue it in the "step" and the joint will be hidden after a fillet or two.