Any tips for riveting the 7/8 flap ribs?

I'm at the point now of closing out the flaps. The procedure I've used so far goes like this:

• Cleco ribs to bottom flap skin and rivet. Access is simple without the top skin in place.
• Cleco the joint between the top and bottom skins. Lay flap on work surface top down. Not too difficult to rivet here with a mini tungsten bar, pulling the skins apart to give more access.
• Cleco top skin to ribs. Examine tiny working space. Consider hiring a midget to hold the bucking bar while I shoot.

But seriously, on the last point...access here is no fun at all. It's tight in there to begin with, and the downward curve of the top skin forward of the spar just makes it worse. We were able to shoot the rivets closest to the trailing edge using this marvel of redneck engineering:





Sadly, it's a one-trick pony, since the whole assembly is too short to use on the rivets closer to the leading edge. We quit for the evening after doing those four(!) rivets. I figure that, worst case, I can continue this theme to buck the rest of the rivets, but that pretty much means making a new tool for each row of rivets, which is hardly efficient.

So I'm wondering if anyone can share how they went about bucking those [REDACTED] [REDACTED] [REDACTED] rivets. Feel free to tell me I'm overthinking the **** out of this, because I have a strong tendency to do that. As my father once told me when I was about 13, I was the kind of person who'd spend twenty minutes trying to figure out how to do a five-minute job faster.

Flaps

I don't recall them being too difficult. I riveted mine while it was in a jig. Seems like I stood on a step and just reached down inside.

wirejock said:

I don't recall them being too difficult. I riveted mine while it was in a jig. Seems like I stood on a step and just reached down inside.

Click to expand...

Hm. Are you doing the V-blocks as mentioned in the instructions? I was avoiding that method due to concern about ending up with a twisted flap, so I've got the flap lying flat on my super-special extra-flat work table I made:



I imagine having the flap upright (open/leading edge end up) would indeed make riveting easier. It occurs to me that I could just turn my work table up on end and achieve a similar result while still assuaging my fear of accidentally building a twisted flap.

It certainly sounds easier than my bucking-bar-on-a-stick.

Bucking bars on a stick work great in a lot of situations, but the key to them working well is in using gravity to your advantage... I.E., orient the assembly so that gravity is holding the bar against the rivet.

Clever tool - it reminds me of . .

Clever tool! I saw (but lost the link) a spring loaded bucking bar with a channel on the lower side that slid between the upper/lower spar on a DC3. It was pulled long by a string straddling the lower set rivets. It was pulled until it hit the next cleco, thus centering it on a new hole. The rivet was inserted, set and then the bar was pulled to the next cleco! I can see why old timers are so valuable in restorations. It might take me years to think of that on my own. I am happy the RV's are relatively easy.

Happy riveting.

Flaps

I used a v-block jig made out of shelving material.
Check out the "aileron/flap" page of my blog for details.
It may have been the bucking bar. Mine is the narrow thin model. It was easy to lay it in place and hold it there.

wirejock said:

It may have been the bucking bar. Mine is the narrow thin model. It was easy to lay it in place and hold it there.

Click to expand...

I'm thinking that may have been part of it. I was just trying to suss out riveting with the flap upright, and I still can't get the mini tungsten bar (1"x1"x2") back there while still maintaining any kind of grip. I see Cleaveland has some tungsten bars that are only 3/8" thick, I think I'll be investing in one of those.

In fact, I might just go ahead and order that and put off continued flap work for a couple days. I figure you can never have too many bucking bars, right? And I can just start tinkering with the firewall in the meantime, and/or do some garage cleanup.