Simple Rivet Question

[Phil]

I got to this point once before and I messed a few things up, so I threw away my work and started over. Now I'm going to get things right along the way.

I've been back riveting 426-AD4's and the shop head is really flat, clean, round, and looks great.

Now I'm moving to the 470-AD4's w/bucking bar. I only drove a couple of them because I wasn't convinced I was driving them correctly. The shop head on these rivets seem to have a minor cup in them. AKA: The center of the rivet seems to be driven more than the edges.

Q1) Is that normal for hand bucked rivets?
Q2) Could I have a pressure problem? Currently using 60 PSI.

Phil

(Yep, I'm a rookie)

[az_gila]

Phil... if I read your description correctly, this is normal.

The standard rivet sets do not completely conform to the manufactured head.. if they did, then you would get "smileys" in the aluminum around the rivet if you were just a degree or two off normal. Because of this, they "hit" more on the crown of the rivet head than the edges.

There is a specification for the manufactured head height after riveting. It is on my web site....

http://home.earthlink.net/~gilalex/r...ec/rivet_a.htm

gil A

[RScott]

As I understand it, you should be running around 40 psi. That's what they say at SynergyAir where I took my builder's class & it seems to work for me. May need more psi with a 2X gun.

Richard Scott
RV-9A Wings