Suggestons for HS middle forward rib-skin riveting

I just got done riveting my first HS forward ribs in last night. I did just the right side and boy was that tough! Obviously the inboard and outboard ones were easy to squeeze, but the forward-most rivets on the top and bottom of the center forward rib were a bear (even with my wife helping me)! At that, it took me two tries (read drill-outs) on the top and 3 on the bottom. They just did not want to set. Even still, now that they are set, they are definitely not pretty looking inside or outside.

Needless to say, before I do the left side, does anyone have any suggestions on how to buck these first couple of rivets? I know that others have mentioned that it was tough, but haven't heard whether others have found a method that was successful. What type of bucking bars are you using? Any tricks that might leave my left side looking a little less "distressed" when I'm all done?

After that frustration, I just skipped to building the VS--had the entire thing riveted together in about 2 hours with only 1 or 2 drill outs (just so that I could get "perfectly" set rivets). It was easy and fun... why Van's doesn't start us with the VS I have no idea!

Any suggestions on the HS though?

Steve

HS center Rib

Steve, one thing that worked for me was to make sure the skin and the rib were held tightly together. I used the HS holder (the plywood cutout) and used post it notes to tweak the fit to hold the skin tightly to the rib. My first one is not pretty, the second one was better. Vans will tell you it is tough to rivet there, do your best and move on. You will forget about it soon enough. It can be filled before you paint too.

Good luck,

Pete

Thanks Pete. It's good to know I'm not the only one! The use of the post-its as shims is a good idea. Indeed, one of the problems I was having is that that forward-most rib flange wasn't setting completely flush and so my rivets wanted to set in between the layers. Jamming the skin farther down into the jig and using the shims may help solve at least that problem.

In any case, I'm feeling better about it now, enough to the point that I went ahead and attached the front spar to the right HS. The rest of this side looks pretty straightforward. Also, the leading edge didn't look as bad this evening when I came home from work as I thought it did last night--a little perspective, perhaps.

Thanks again.

Steve

Those are the toughest rivets in the entire airplane!

Steve,

Those rivets drove me nuts and I trashed one skin and a nose rib doing them. Mine came out so bad that I had to replace them.

Now that I have some very small tungsten bucking bars and some more experience driving rivets, I?m sure I could do them again w/o any problem. As the guys at Van?s like to say, ?Keep driving those rivets.?

If you heat your rivets up to 400 deg. F. in an oven, let them cool off, you can then set them with less force. The heating softens the alloy temporarilly. In a few days, after you have set them, they return to their normal hardness. Another thing to check, throttle down your gun with the little regulator valve and set it while holding it on a solid wood block or table. This will help properly set your gun. It should not be banging into the table, just nice taps. Throttle back till it just barely works, then ease in a few clicks til it sounds right. Go back to practicing on some scrap, if you think your feel for the gun has slipped. It happens. The 3/32 rivets don't take much to set.

Roberta Hegy
RV-7A N2447A



Notice the nice Madrid Red shoes

Thanks for HS suggestions

To all those who provided advice on this question, I really appreciate your help.

I took a little bit of advice from everyone (from both here and the Yahoo forum) and came up with a perfect left side...

In short, I--

1. made sure the flanges of the forward rib where flush and sitting against the skins completely before any riveting.
2. Moved the jig supports very close to the center rib location.
3. Used my squeezer yoke as a bucking bar, and only used very light bucking bar pressure.
4. Heated my rivets to 400 degrees F to temporarily soften them (supposedly they return to their normal hardness after brief period of time).
5. Set the rivets with only about 30-35 # of pressure.

Again, it turned out perfectly. In fact, it turned out so much better than the first right side, that I am probably going feel the "need" to re-do the entire right side, which means not only new skin, but also new ribs and an entire new front spar assembly because I was dumb and riveted my imperfect skin to what had been a perfectly good front spar and its associate nose and main ribs. Oh well--it's going to cost me about $300 probably, but lesson learned. Also, I learned a few ideas about getting the spar-rib rivets in much better, so I think I can make a much better HS the second time around.

Thanks again for everyone's help.

Steve

Good Job!!! That's how we learn. Better to do it right now. Repairing later is a lot harder. You'll be a pro by the time you get the emp all done.

Roberta