by DCASonex » Mon Feb 12, 2024 6:20 pm
The aluminum rivets I used when riveting into fiberglass are the from a Zenith kit and I think were listed as Avtech A4 (1/8") rivets. The Avex rivets look like they may be similar. They are identified by a small groove around the stem that creates a weak area where bulging first starts, then the bulge is pulled down onto the fiberglass clamping it to the aluminum. If you pull a standard Sonex rivet into fiberglass it bulges outward inside the fiberglass and tends to breakout if near the edge. Try this with some scrap material. The Sonex SS rivets are much better when fastening two pieces of aluminum together as the expansion eliminates and lateral movement between the parts. Zenith uses (or used to use) Avtech or an equivalent rivet and I made a test Tee square with just a couple of rivets at the joint, this movement is very evident with these rivets. I also used the aluminum Zenith type rivets rivets when fastening aluminum piano hinges to fiberglass even though the head of the rivet is on the fiberglass the SS rivets tend to distort the piano hinges in this application. Just be sure your aluminum rivets have the groove and that they first form a bulge when pulled and then pull that bulge back onto the materiel clamping it, test on some scrap if in doubt.
12 years in service so far, no sign of any problems with those rivets.
David A.