Category Archives: Wings

Time: 5 Hours

Today I decided to start work on the leading edges since I will need to have them riveted on the main spars before I can rivet the wing top skins. On the left wing Vans’s gives you an access plate on the bottom of the leading edge skin for a stall warner. I’m not going to us it instead I will have a AOA (Angle of Attack) gauge for much better indication of a stall approach. So I needed to fabricate a plate that will fill in this area. I decided to make it removable since it’s there and you never know what you may need to access in the future.

I dimpled the plate for the #6 screws that will hold it in place. I also riveted the matching holes on the trim that it will be screwed to. I also dimpled all the holes for the nutplates as well as the rivet holes for the trim to skin.

I then turned to the rivet holes in the skin while the primer was drying.

I then took the leading edge apart to debur the ribs and dimple them. I started with the outboard rib and worked my to the inboard. If you remember a while back I had to make the splice plate that will attach the inboard of the leading edge to the outboard of the fuel tank by match drilling the skin to splice plate and the underlying rib. The splice plate and rib had no holes so that they could be created in line with the skin. I guess during the drilling I allowed the rib to slide into the skin of the leading edge allowing the holes on the rib flange to be closer to the rib web vs in the center of the flange! So this rib was toast as it really violated the edge distance rules.

So I cleaned up the shop so that I could pull the truck for the night and jumped on the computer to order a new rib after I checked that the right side didn’t have the same problem. I have my recurrent flight training in Tucson next week and will get to work on the new rib when I get home. As always there is plenty of other stuff to do in the mean time!

Time: 6 Hours

Today I set out to treat all the countersinks that I did over the last two days. You can prime these individually, prime the whole flange or leave them completely alone. I decided to try my hand at using Alodine. This is a chemical process that converts the surface of the aluminum and provides corrosion protection. This stuff is pretty toxic if you get it on your skin, I think it’s the stuff that the movie about Erin Brockivich was based on, yikes. So I am using all my protection like gloves, goggles and respirator. In most cases you would need to treat the aluminum with an acid called Alumi-Prep to etch the surface prior to usin Alodine. I’m not doing this for two reasons, 1) since these holes were just cut they have no oxidation to remove and 2) the acid needs to be rinsed away really good and these parts are riveted together already and I would have the possibility to trap some of that acid in between parts which could promote corrosion. So I just used a q-tip to apply a little bit if the Alodine to the holes and wait 2-3 minutes before rinsing with water. Pretty easy process all in all and I really like that they match the yellow of the rest of the spar.

The process took several hours since there are sooooo many holes! After a dinner break I started working on removing all the necessary blue film on the skins so that I can debur, edge finish and dimple them.

To help remove large sheets of this film I used a broom stick (I read about this on another blog) and it worked really slick.

I don’t like writing about days like these as they are long days and not much to show!

Time: 6 Hours

After lunch today I ran to Harbor Freight to grab a couple of moving blankets, the kind you would see in a U-Haul moving truck. I figure these would be a nice padding source to lay the fuel tanks on so I could regain the use of the workbench. I capped off the vent line with a -4 flared cap similar to the one I used for the flop tube line so that fuel wouldn’t drain as the vent line would be at the bottom of the tank as I laid them on their top skins. To prevent to tanks from getting damaged from expansion I removed the fuel drains, as they are now in top, to vent the tanks. I’ll let the tanks sit in this configuration for a few more days.

I then moved on to the main spars. You need to countersink every hole that the skins will get riveted to so that the skins dimples have a place to rest. I had to remove both leading edges to get to those holes.

All I can say is there are. Lot of these holes and my cordless drill is working very hard. I stopped after one full length to let it cool down. This isn’t very hard work, just tedious as there are 377 holes to countersink per wing! It took me 5 hours to drill all 754 holes! My hands hurt from holding the drill for that long! I cleaned up the shop and called it a night and look forward to another good weekend.

Time: 2 Hours

Today I tackled deburring and dimpling all the holes in the left wing ribs as I did for the right wing. No pictures of that but I did create a time lapse video of that work here. I also used my deburring bit to touch up the dimples on the rear spar where I had to dimple way back in the build process as per the plans. You just need to remove a very little bit of material to help the skins dimples sit flush.

my cat Harley found his new favorite spot to watch me work.

Next up tomorrow will countersink all the rivet holes in both main spar flanges.