I have a single sharpie mark at 20 deg.
Me too, I think - I used full down aileron to set the mark. I had used an inclinometer to find different flap positions, then reverted to the KISS method.
I printed an adhesive label with 15, 30 and 40 on it in the right spots for them to line up with the top skin. Stuck it on the left flap and covered it with the flap tape.
I am with in hours or days of getting back in the air. Long story. I can't remember the flap speed I was using . What is desired speed for first flap,setting in a RV 4 ? Thank you. Ward Combs 402 871 1139 Blair, Nebraska. (BTA)