FWIW, my (purchased) '91 RV-4 has had the original stainless tape on the flap faying surfaces since new. Invisible with the flaps up, and a nice flap angle indicator as they're extended (if you bother to look). :-)
Felt tape is a good idea. Recently painted my RV4 and used the 3M paint protective film from Flyboys and Teflon tape under wing skin. Looks and performs great, hardly noticeable. My flap to wing is a tight interface and this combination works well to help reduce friction. As mentioned, use masking tape as guideline for a nice straight edge, float it on wet and work out the air bubbles.
Thanks for the replies. Does anyone have experience with using Velcro loop on the underside and the flyboys 3m tape on the flap? Leaning that direction.
Linear Mode
