On which side of this would you put the manufacture head?

For the AN470AD4 rivets that will secure these ribs to the bulkhead, I could have the manufacture head on the aft side, which puts the shop head on the web of the thicker bulkhead, but requires setting with an offset rivet set. Or, I could put the manufacture head on the forward side, which allows me to use a standard rivet set but has the shop head on the thinner rib flange.



Which way would you do it?

Edit: I ended up putting the manufacture head on the rib side. Due to lightening holes I was able to squeeze all but 8 rivets. The rest with the offset rivet set went fine. Would have been a bear if I needed to drill one out, but thankfully I didn't need to.

I never found using the offset set particularly difficult, so I’d put the factory head on the thinner piece.

Shop head

Agree. Stick with Mil-Spec. Factory on thinner side. Off set is no big deal. Tape it to the gun so it can't rotate while working.
Practice on scrap.
I set up a neat back rivet bench for basically the same job on my 7. Two benches end to end. Blocks either end high enough to allow the back rivet bar with a tungsten on top. Foam on top of the blocks. Insert the rivet and push down till it contacts the bar then bang. Every rivet came out perfect and no struggle with holding the bar. Both hands were free to control the gun and offset. The foam allows the spar to sag just enough to set the shop head. Worked great.

Agreed to all. One other consideration, if material thickness doesn't matter is which side will be easier to drill out of you ever need to. Put the Manufactured head there.

+1 what everyone said,
I would add that I noticed less "hammering" with the offset.
I increase the gun pressure by ~10lb to get the same bucking "force"
Is it just me ??

Whatever side is easiest. There’s no structural reason to have the factory head on one side or the other.

Pressure

riseric said:

+1 what everyone said,
I would add that I noticed less "hammering" with the offset.
I increase the gun pressure by ~10lb to get the same bucking "force"
Is it just me ??

Click to expand...

Nope. +10psi is about right.

There is so much flex in these ribs you can do it with a long straight cupped set and the manufactured head of the rivets on the flanges of the rib as per recommendations.

https://tasrv14.blogspot.com/2022/11/26-03-07-seat-ribs.html?m=1

Same is true when you riveted the baggage ribs to the other end of these ribs.