Both my cunningham and vang controls currently terminate at the base of the mast and I want to run them back to the top of the cabin to cam cleats adjacent to the traveller. This exercise will involve securing a number of fittings (2 x blocks at the base of the mast, 2x fairleads and 2 x cam cleats) to the cabin top.
My question for the collective knowledge of the forum is this - Should these fittings be through bolted or is it sufficient to use s/s seft tasppers into the cabin top? Cabin is GRP and as far as I can tell a good thickness throughout and solid.
My preference woud be for the latter (less holes through the cabin to let water in the better). But I wonder about screwing sef tappers into fiberglass, it's not like wood that has a bit of give in it to take the screw.
Photos help.
I'd go though bolts with good sealant. Given that the vang takes one hell of a shock load during those heavy running gybes, I reckon the self tapers would not last as well as bolts.
Poods
Now MatM14,
From your photo I think you have a 25 footer or there abouts, correct?
If so, I'm doing the same thing at this very moment on my Top Hat.
So, if I'm right, its through bolt of around 6-7 mm of fiberglass.
Don't forget to put in a chamfer, as if you were using a wood screw,
on the top of the deck so that you retain a bit of whatever sealant you use around your fixing bolt.
Any shockload from a vang (big broach and no dump on the vang - boom hits the water at speed) will slowly (or more quickly) work the self tappers out.
Go the bolts with a large penny washer under the nut to spread the load..
