The fins are pre-cut from G-10 fiberglass. They are thin, about 1/16" thick.
The edges are a little rough. I cleaned them up with some 220 grit sandpaper.
30 minute epoxy was applied to the root edges and TTW tabs. When these are slipped into the thin slots some of it will be left of the tail cone. You can't do internal fillets on this design. To increase the amount of epoxy on the inside I applied epoxy once and slid in the fin. The fin was pulled out leaving some epoxy inside. More epoxy was added and the fin slid in again.
To keep the fin straight while it dried, some masking tape was set over the outside edge of the fin and tail cone. Epoxy will run so the glue was allowed to dry in this position.