by GreenLake » Fri Jun 02, 2023 10:12 pm
Aluminum rivets are preferable from the point of not introducing dissimilar metals at the mast/boom rivet connection. The fittings are SS, so you still need to use TefGel between them and the aluminum of rivet and mast. (sells in a really tiny container, but a little goes a long way, and it's indispensable).
My take on the gooseneck is that when the sail is rigged and sheeted home, the force on the boom will compress the gooseneck, more so, if you installed a vang. That means, the connectors are basically there for when you take the boom off the mast, and I believe you can get away with ordinary aluminum pop rivets. However, read back just a few posts here and you find a similar case discussed. In that instance, the owner decided to tap the gooseneck fittings and use machine screws. (With TefGel). So, you have options. The key is that the gooseneck fitting is a substantial piece of material, not as thin-walled as the mast or boom. That makes tapping and using machine screws a good option.
For the mast fittings, like shroud attachments, I would start with a close visual inspection. Do you see any loose rivet heads, any (powdery) evidence of corrosion? If not, you may not need to do anything. If you need to replace rivets, look up specialty fastener stores if you have them in your area or go online to try to find the most compatible style rivet.
I had both of the rivets fail on one of the spreader attachments, and failing to get matching rivets with a captive stem, I simply "spiked" the ordinary hollow core with a short length of aluminum rod. My thinking was that whatever extra strength a captive stem could provide, would not depend too much on anything other than filling the hollow space (and it also sealed the mast at that spot). I did that repair when I was a new owner and there hasn't been any other rivet failure (and the repair has held).
~ green ~ lake ~ ~