How to mount bracket to mast top

[Timccarpenter]

I’ve got a Tartan 27 that I’m installing an anchor light on (didn’t have one). There is a cast aluminum top that slides into the top of the mast. There are two threaded holes on the side of the mast cap that I’m thinking of using to mount my anchor light bracket. Because of access, I can only screw in stainless bolts with no nuts. Is there something I can do to keep the bolts from vibrating out? Use locktight? Should I be driving larger stainless screws in instead of bolts?

New to the forum so thanks for the help.

[thinwater]

Originally Posted by Timccarpenter

I’ve got a Tartan 27 that I’m installing an anchor light on (didn’t have one). There is a cast aluminum top that slides into the top of the mast. There are two threaded holes on the side of the mast cap that I’m thinking of using to mount my anchor light bracket. Because of access, I can only screw in stainless bolts with no nuts. Is there something I can do to keep the bolts from vibrating out? Use locktight? Should I be driving larger stainless screws in instead of bolts?

New to the forum so thanks for the help.

Locktite is good.


Never use self-tapping screws in a mast; the points are needle sharp, the threads are sharp, and they will chafe wires and snag lines.


Tap then Locktite. More realistically, if you tighten firmly it is seldom a problem. The more serious problem is not being able to get them out!

[marcjsmith]

Because you’d end up with corrosion between ss and Al as thin alludes to… I’d use tefgel on the bolt threads and a lock washer.

[rls8r]

Locktite provides thread locking - but does not protect against galvanic corrosion or galling.

Tef-gel provides protection against galvanic corrosion - but does not provide thread locking.

I'd suggest that you use DuraLac - which provides both protection against galvanic corrosion and thread locking (with a strength similar to, but perhaps just a bit less than Loctite blue).