I received the new W-1204B outboard wing skin today and went right to work to take off the old skin and prep the new skin. It looks like the W-1213-L triangle rib was in good shape, so I only replace the skin. I drilled out all the surrounding rivets head with a #30 drill; I then followed up with a #40 to drill out the center section (best to use a drill stop as well). The new skin fit perfectly and riveting was fairly easy except for the trailing edge corner rivets. Not sure why it was designed this way, but the lower rivets line up with the upper rivets, which doesn’t allow the rivet to fully seat. I recall that I purposely did the top skin first, and then I did the bottom the first time. I should have done the same this time, but it came out ok. I just had to work at it. Anyway, that’s done and now I can move on to fixing the cooling door hinge.
