Protecting end grain

[mariner2k]

More broken mast related stuff. I'm somewhat convinced that the end grain around to the sheave may have been the culprit. The top has a solid cap. The sheave has some protective sheet bronze protecting the wood but should have been upgraded. It was kind of cheesy, but lasted 80 years. Any thoughts on this detail would also be appreciated

[Peerie Maa]

More broken mast related stuff. I'm somewhat convinced that the end grain around to the sheave may have been the culprit. The top has a solid cap. The sheave has some protective sheet bronze protecting the wood but should have been upgraded. It was kind of cheesy, but lasted 80 years. Any thoughts on this detail would also be appreciated

Unless you remove the bronze sheet and paint or varnish underneath it regularly I think that it is nothing more than a moisture trap. I dismantle the sheave and its bronze anti-chafe plates completely and varnish every time I re-varnish my mast.

[Andrew Donald]

Fibreglass the end grain and paint it. Slope it so water runs off. Top of your (most are) mast is white any way isnt it?

[mariner2k]

This wasn't painted at all. Just 14 coats of epifane. I would have thought it may seep in around the bronze sheet.
I've seen sheaves within a bronze casing, where the whole assembly fits in the slot. I may investigate that.

[wizbang 13]

The "whole assembly" can get sweet water wicking up in there as well, no ?

[David G]

The simpler the better. Slope the top. Soak with epoxy or CPES. Varnish maybe... paint better. Perfectly traditional look to have the tip of your spar painted white. That eliminates crevices. And eliminates fasteners which are often the source of rainwater intrusion. If there's a thru bolt for a pulley... epoxy that hole also before you insert the axle. Or go full-tilt, and create an epoxy annulus. For details, consult https://www.westsystem.com/instruction-2/ especially "... On Boat Construction".

[coelcanth]

i've been pondering similar questions relating to how to fasten a masthead light into the endgrain at the top of the spar..
right now i am thinking of drilling and filling with epoxy and then bedding the base well with butyl tape