Flap riveting sequence - backrivet?

[Flying Scotsman]

Anybody see a problem with backriveting the interior flap ribs the bottom skin, then squeezing the aft "spar"-to-rib rivets, THEN clecoing on the top skin and pounding the rest of the rivets?

I'm trying to figure out the easiest ways to do things single-handedly...

ETA: Scratch that. The double-offset backrivet set that I have won't work, so I'll have to do with a flush set and a bucking bar.

Any advice on this? I'll build a cradle, of course...how difficult is it for one person to set these?

 

[splevy]

Flap Rivet Sequence

Given Van's warning about being able to build the flap with "unacceptable twist" I don't think you want to rivet it together piece meal. Having it fully clecoed together gives the best chance of all the parts settling into the straightest configuration.

I used a cleco in every other hole and put it into a fixture similar to the tank/D-section fixture but cut to fit the flap profile (use an end rib as a template and take care to be sure the two cutouts are parallel). After removing the spar, you can lay the fixture down on the bench (make the fixture wide enough to allow the clecos to clear the bench) and reach in with a bucking bar to set the rib to skin and top/bottom skin rivets.

I used one of those tungsten bucking bars, and the small size made it fairly easy, although the bar had to be held on my fingertips in places. It was also handy for the top skin to spar rivets since it has one end cut at an angle.

Just finishing the second flap, and they seem to have come out fine.

Stan

 

[Flying Scotsman]

Thanks, Stan...I built the cradle tonight, and will rivet the thing together tomorrow. Wish I had one of those tungsten bucking bars . Pounding those flush rivets single-handed seems a bit daunting, but there's a first time for everything, I guess.