Wing rear spar riveting

[FlyGuy65]

Riveting ribs to rear spar and am having great difficulty with poor riveting (smilelys everywhere but on my face!). First question is which side to placee the manfactured head on. Ribs are the thinner material, but spar is the outboard side and would make for easier removal. George O. video shows holding manufactured head on spar, holding the rivet gun pointing upwards with thumb on trigger and basically riveting blind while sitting on stool.

I am going to experiment with tape, snap locs, 3x gun. Guessing that if 2x gun leaves smileys then a 3x gun would be even more likely to do that? For now using 2x gun with 42 or so PSI. Used tungsten bar, but thought maybe that was too much downward force on rivet so tried old steel bar, with no improvement.

Now that I'm reviewing the video, he has one skin clecoed on. Perhaps that is needed to give some rigidity, esp on aft spar?

Thanks for any suggestions.

[wirejock]

Originally Posted by FlyGuy65

Riveting ribs to rear spar and am having great difficulty with poor riveting (smilelys everywhere but on my face!). First question is which side to placee the manfactured head on. Ribs are the thinner material, but spar is the outboard side and would make for easier removal. George O. video shows holding manufactured head on spar, holding the rivet gun pointing upwards with thumb on trigger and basically riveting blind while sitting on stool.

I am going to experiment with tape, snap locs, 3x gun. Guessing that if 2x gun leaves smileys then a 3x gun would be even more likely to do that? For now using 2x gun with 42 or so PSI. Used tungsten bar, but thought maybe that was too much downward force on rivet so tried old steel bar, with no improvement.

Now that I'm reviewing the video, he has one skin clecoed on. Perhaps that is needed to give some rigidity, esp on aft spar?

Thanks for any suggestions.

Make sure you have the correct size set. You may be able to set some with a squeezer.

I use a Sioux 3X at 30 psi and a tungsten bar. All factory heads are on the thinner, rib side. What really helps me is black Gorilla tape. A 1" strip is good for about 4 rivets. It leaves a little residue that is easily scraped off with a fingernail.
I have heard of some using a flat set but that seems more difficult to keep the set on the rivet.

[FlyGuy65]

And another question: rivet the spar/ribs together on the workbench and then move to the jig, or clecoe together on the jig and go from there? it would seem to be an akward to move the completed assy to the jig, but riveting on the bench seems easier.

[GeoffP]

When I did my wings fairly recently, I did find the rib to spar rivets (both main & rear) to be a bit tricky. In the end, this is what I did:

Cleco'd the entire spar / rib assembly together. Did all the spar to rib riveting on a bench, and as Larry mentioned had the manufactured head on the rib flange side. I used a double offset rivet set which makes it easy to hold the gun parallel with the rib while still having the set on the head of the rivet. Gorilla tape around the rivet set on the gun, and I also put rivet tape over the heads of the rivets. Ultimately I got the best results when my son helped buck for me, as it meant I could concentrate fully on the gun position and angle.

And yes, the inevitable happened to me also, and while these rivets are hard to drill out, it's not impossible. Some I drilled out from the shop head side (where access was much better), obviously with care, and I placed a clamp to hold the rib flange to the spar when I knocked the rivet out so as not to bend the rib flange.

It wasn't hard to move the whole assy, it's still fairly light just make sure there's plenty of room to swing it around, or get some help for the few minutes it'll take to re-locate it.