Another lesson learned

[jcoloccia]

I had to drill out a rivet at the intersection of the VS-707 rib, the spar and the skin on tht RV-7 vertical stab. After drilling out the head, I went to tap the back of the rivet out.....BAD move. I bent the tab on the rib (duh...if I had been paying attention, I would have realized what a bad idea this was).

Of course, you can't just bend it back up because it's all rivetted in there and I would have had to bend it through the skin to account for the spring back. My tech counselor and I attempted to straighten it out by tapping on the tab's flange at the bend. Rib cracked. :::sigh:::

So now I had to drill the rib out and get a new rib. Of course, drilling the AN4 rivets attaching it to the spar is difficult because there's not enough room to really get a drill in there to do it. Muffed up one of the holes....enough that I need to drill it out to #12 to make it round again. Also, I now have to use blind rivets there or drill off the whole skin (with the inevitable enlarged holes). Yuck.

I have an e-mail into Vans....I'm sure this will all work itself out, and I've got plenty to do while waiting for parts to come in.

In retrospect, I should have just bent the tab up as much as I could, held it up there by hand and put a flush cherry rivet in there. Better yet, I should have been paying more attention to what I was doing and not bent it in the first place

Live and learn.

[Davepar]

I learned this from somebody else. When drilling out AD4 rivets, drill out the head with a #30 until you can pop it off with a punch. Then drill out the rest of the rivet with a #40. It pops out much easier that way.

[TShort]

What I've been doing to drill out rivets is to use a drill bit that is a few number sizes smaller (i.e. a #42 to drill out a -3 skin rivet). It is easy to center the bit on the indentation in the rivet head, drill down to the shaft, then pop the head off and push the rest through. I find this keeps from enlarging the holes if you are careful.

Thomas
-8 flaps

[LettersFromFlyoverCountry]

I think one of the hardest things abut building is learning when to drill out a rivet and when just to leave it alone. Even using a rivet removal tool, I've made things worse on a few AD4 rivets.