RScott

Well Known Member
This is just an idea that came to me after I was almost finished (naturally!) riveting my lower wing skins, so I offer it up to anyone who might want to test it.

The most difficult area for me was riveting the skins to the spar. The problem is that you already have a row of rivets holding the leading edges to the spar or a row of nutplates holding the tank to the spar. So you reach thru an inspection hole, then thru a lightning hole and by feel set the bucking bar in position and with the first hit of the rivet gun the bar starts bouncing around, either onto the adjacent rivet or off the target rivet.

So yesterday, I taped a block of wood to the bucking bar to use as a spacer to help accurately position the bar the right distance from the spar so it would only be on the target rivet and not on the one holding the leading edge. Worked great for the first 2 or 3 bays, but as we worked inboard, the spar step that makes the spar thicker put the bar too far out.

So the suggestion: Before clecoing the skins, cut a set of blocks for positioning the bars, numbering the blocks and bays so you can use the right block for the bay. May not work for all locations, but since my skins are now on, I can't check it out. But it ought to be worth a try.

If you try it, let folks know how it works!