Has anyone ever had a really rough paint job on top of a wing act like frost... and effect stall speeds or climb performance. Flew something the other day that just didn't act right. Looked closely at the top of the wing, and the paint was chipped and flaking something terrible. Looked as rough as a good layer of frost. Recent years, warnings about frost have gotten more detailed, so just wondering.

I imagine rough paint would make a difference.

Well, I flew the plane again after sanding the crap out of the top of the wing... it stalls slower now and climbed 200 fpm better. Guess there was some drag there.

Especially if edges of the paint chips are sticking up, it will be especially bad. Any roughness is bad. Think fiberglass vs rivets, and even countersunk/flush rivets. The effort is worth the reward if you are looking for every little bit of performance, so it works the other way as well. I won't fly a frosty plane, especially something low powered. Early separation is a very bad thing.

I've never had a problem with rough paint, because my airplanes don't seem to have any paint on them. However I have learned from experience that a good layer of "bug-splat" on the leading edge of a C-150 wing will slow it down about 5 mph in cruise and cut the rate of climb in half.

We used to have days of this weird freezing mist up north. Not fog or freezing rain, it wouldn't be anything close to being IMC. But a mist that you might have 10 miles vis in. Almost too faint to see. And not very often. Maybe once every couple of years I would run into this phenomenon.

But the stuff would stick to the airplane all over. Bottom of the wings, along the sides of the fuselage, and not just on the leading edges like standard airframe icing. It was all over the place. Little spikes of it would start growing, maybe 1/2 inch or so. Little bumps here and there. And when it did, you'd better start puckering. That crap would eat up airspeed in a big hurry, and it was balls to the wall sometimes to get on the ground under control and not falling out of the sky.

I can see where some big patches of paint peeled up might have the same effect.

Gump

A bit off topic... but I put REJEX on the leading edges. It is not wax, but it seems to keep bugs from sticking so bad. They wipe off pretty easy with a rag. One bottle will last years... though it is pricey at about $20.

I was just thinking, what with below freezing temps now it is probably time to get the bugs and cow crap off the wing for the winter!

The biggest unexpected thing about ski flying for me was how clean the airframe and windshield stay all winter. Nonetheless, I just bought some of that Rejex stuff, sounds good.

Seems like something called "rejects" would be pretty cheap....