I always use large aluminum pop rivets with a large, long handled rivet
puller. I also use sealant in the holes, but I also use a gasket of sail
cloth in between. The gasket I apply first with contact cement, then I drill
the holes, then the sealant. The gasket prevents mast paint damage as well
as protection from electrolytic corrosion. Whatever fastener system you use
should never be the weak link of the assembly and with the thin wall
thickness of the mast, screws are not an option and because of the thin
wall, many rivets are necessary to spread the load.
Steve

"joost" wrote in message
...
I am investigating the best way to fasten a 4 metre long alu t-track
for my whisker/spi pole to the alu mast.

Currently I have a short length of track (1 metre) which is fastened
with SS screws. I am not satisfied with this, because the screws react
with the aluminium of the mast and dissolve the thread. The track
comes off. I also find it quite difficult to drill and tap the holes
in the mast accurately sitting in a bosun's chair.

My question is whether it would be better to fasten the track with SS
rivets dipped in some isolating compound. At least I wouldn't have the
problem of the tiny threads corroding away and loosening the
fasteners. Also I think that I have a bit more tolerance for drilling
the holes + I can reuse the existing worn out holes to put the rivets
in (instead of tapping one size up).

But, how strong is it compared to screws?

And, how would I go with off-the-shelf T-track which is made for
countersunk heads?

Any thoughts?

Thanks,
Joost.