I am prepring to counter sink my RV-9 wing flanges for #8 screws. Working on scrap of similar thickness as the wing flang, I found that to get the #8 screw head to fit flush the counter sunk hole had to go well beyond the depth of the material enlarging the hole well beyond #19. I suspect this is ok, since the platenut will server at the attachment point, not the flang itself. Is my understanding correct?
Also, to assure the counter sink does not wander, the instructions suggest to rivet on the platenutes and us them to guide a #30 counter sink. I have read elsewhere that some builders make a jig/guide and use a #19 counter sink instead. Recommendations?
Also, to assure the counter sink does not wander, the instructions suggest to rivet on the platenutes and us them to guide a #30 counter sink. I have read elsewhere that some builders make a jig/guide and use a #19 counter sink instead. Recommendations?