Starting to work on the Leading Edges

I have not posted anything in a while because the work I have been doing has just been duplication of the left wing deburring on the right wing skins and ribs. I finally finished all that deburring today, so the wing skins and ribs will be ready for dimpling soon, after I manage to prime the insides of the skins. I removed the bottom wing skins from the left wing per Vans instructions, and left the top skins on.You need to have access under the wing spar for fitting and drilling the leading edge ribs to the spar, so the bottom skins are removed to allow this.

The next step was to remove all the vinyl from the inside of the leading edge skin. Being my usual frugal self I decided to use my soldering iron to remove the vinyl only from the rib lines, leaving the rest to protect the skin from any scratches or dings. I have had the left wing leading edge in the cradle now for a very long time, with the ribs clecoed in place. I remember I wanted to see how easy or hard the ribs could be clecoed to the LE skin. THis also verifies how well you straightened all the LE ribs. Contrary to Vans instructions at that time I left all the vinyl in place on the skins. Some of the holes were difficult, but I managed to get all ofthem installed.

Either Vans or some other builder also suggests to knock down the flanges that are cut into small separate flanges that go around the circumference of the very front part of the leading edge skin. I had straightened all of these separate small flanges long ago, but had not done any further prep work to debur or smooth out the fronts of the ribs. Because of this, and the need to remove the vinyl for correct fitting of the ribs to the skin, I needed to remove all the clecoes and remove each LE rib. This went pretty well, but some of them were difficult since the holes have not been match drilled yet.Before I removed the clecoes from the ribs I took the soldering iron and used each rib flange as a guide to melt the vinyl. This also worked pretty well.

You are supposed to knock down the rough edges of each of these small flanges because if you don't small bumps will appear in the LE skin that apparently are somewhat visible after painting. There is also a possibility that stress risers will forming that area and possibly cause the skin to start cracking. If run your finger around the front of each rib you can feel the high spots created by the bends and relief holes of each of these flanges, and so the acid test for smoothing these out is to feel no sudden stops with your finger and everything should feel smooth as your finger follows the contour of each rib.

The only question now was what method to use to smooth them out. I had already tried using the scotch brite wheel to do some of this, and it just did not work very well. Tonight I decided to try using 220 grit aluminum oxide sandpaper. My past experience with using the sand paper  for removing or smoothing large areas with significant amounts of material to remove is that this takes forever to do,even with 220 grit. You also need to be careful because you do not want to remove too much material.

So after the first rib I gave up on the sandpaper, and switched to a standard sized flat file, and two other smaller jeweler files that I have used in the past for the smaller ribs for the tail section. The flat file actually did a nice job of knocking down the high spots and smoothing out the transition between each small rib flange on the nose of each rib. I kept running the file over each adjacent set of flanges until the entire rounded surface felt smooth. I used a round jewelers file to smooth out the relief holes.

I managed to smooth out all of the ribs for the left wing LE, and now that I have all of the vinyl removed as well, tomorrow I will re-cleco all of the ribs back into the LE skin and fit it to the left wing spar per the instructions. Then I will be able to match drill the holes. There are some questions that I may need to ask Vans about next week. I am not sure if I will need to kerf the LE skin so that it does not curl up on the edge against the spar, and I am not sure how much,if at all,I am supposed to debur the edges of the skins,since part the process for all this is to ensure that all the separate skin sections for the wing, LE, and fuel tanks all butt up against each other without any gaps. Gaps between the skins sections will generate drag, which the enemy of speed.

Anyway, all for now, more fun work to do tomorrow. Man am I glad that all that deburring is done. My fingers are shot from doing the back sides of the wing ribs by hand.