Mast fixings

[zoidberg]

I need to mount several items onto an anodised aluminium mast, including a masthead bracket ( aluminium or S'S ) to hold a VHF antenna, halyard guides ( S'S ) and mounting plates for clutches and/or winches.

Conventionally, pop rivets. However, what are the pros and cons of using rivnuts and threaded S'S fasteners?

 

[William_H]

I would suggest drill and tap a hole for 5mm screws. Use lots of duralac or similar to stop corrosion around the screw and under the ss bracket. ol'will

 

[thinwater]

Oh no. Like an anchor thread!

Searching the topic will get you lots of answers, I am sure.

 

[Neeves]

Our brackets, or saddles, for the mast located winches and clutches, are all aluminium and secured with bolts. The components are attached separately to the brackets. The bolts for the brackets are tapped to the mast.

However - our mast is of a beefy construction and lacks any flex, we don't have back stays, nor runners, and the beefy section imparts strength b=- and is conducive to tapping. I suspect a thinner wall construction, for the mast, might be less conducive for tapping.

Whatever, or however, you decide to attach be mindful that a neat row of holes on each side of the mast will weaken the mast and you should try to stagger the holes (and thus attachment points). It might not look 'right' but will not provide a perforated area or line - just ready to be a point of failure.

Jonathan

 

[PetiteFleur]

If you use pop rivets, make sure they are Monel - not aluminium. You'll need a heavy duty riveter to set them. And use Duralac. I've also used Rivnuts for some situations on my previous boat.