Cefirmeza wrote: ↑Wed Jun 19, 2019 5:43 pm
Can someone tell something about the performance issues or feeling after a fixed or sanded wingtips?
I bought a second handed kit with some work done on the wing so I have no comparison to make. How bad it could be until it may compromise the glide feeling?
yes,
I have kept a new 633 with a new 483 stab, I only use it when benchmarking the performance of my in use sanded wings, front and rear, which have rounded tips for safety and blunted trailing edge so I can press my hand hard on the thin edges and and run along the full edge without fearing a cut, but I have also sanded all working surfaces to also remove all factory imperfections, tiny lumps and bumps that are always there, also the paint that is too thick around the trailing edge that causes a tiny inverted lip, (on many front and rear wings) and most guys are not aware of it, just hold a flat edge rule on the trailing edge or simply use your fingers to feel this raised flip on the sharp edge.
I use grit paper and go right back down to the base carbon, removing all paint and logo transfers with 240 paper, fill any tiny air holes with glass compound, give 2-3 coats of acrylic matt black, let cure for around 6 hours at room temp and then using 800 paper polish the surface gently front to back then as the paper starts to stick a little, swap over to 1200 or 2000 paper for a superb glossy matt perfect finish, run water over the full surface to check it sticks on every bit of the surface creating a mirror type finish from edge to edge.
I have found my "In Use" used wings with blunted edges and rounded tips are smoother and as a result feel slightly faster than my brand new wings, which I put down to how stable they are at top speed.
I find its easier to maintain the finish when the surfaces have been fine finished to glossy matt finish as well, any marks are easy to remove with wet 2000 grade paper, leaving no rubbing/sanding marks when finally dried off with microfibre or dry clean tissue paper.
All references to using grit paper are used of course with lots of fresh clean water, never allowing the paper to grip and stick.
and trailing edges are always finished off with 600 paper wrapped around a small wood block, using 4-6 strokes at 30deg on each side and then blunting off with 2 full length strokes at 90deg, then skin test carefully, and one or two more strokes at 90deg if not happy, (pictures of this glossy matt finish below)