Congratulations, Annie with that mast top -
you surely aren’t shy of taking on tricky jobs! Without much skills in wood-working, and without an equipped workshop, I have always given those mast jobs to Curtiss Boatbuilder. Don’t ask me how he does it, but the masts from him always look as if coming right out of a giant lathe.
The top mast for my Ingeborg was simply made of four planks. This results in thicker walls and a heavier mast, but since spruce was used for it, it was good enough.
To glass or not to glass, and how...
Malena’s second, hollow mast (1995) was glassed with epoxy and then covered with seven (I think) coats of 2-pot varnish. This looked great for many years after I sold the boat, but around 2010 it showed signs of decay. The owner at the time didn’t take action, so a bad rot-spot developed (..I refuse to baby-sit later owners of my boats...), and in 2012 the mast ended up as firewoods.
Luckily, after glassing Johanna’s mast the same way (2002), I painted it with white 2-pot polyurethane paint, and hopefully, this still keeps the UV-rays away from the epoxy.
The topmast of Ingeborg (2016) was only varnished and then painted with 2-pot polyurethane - no glassing. Next spring I will go up the mast (or up in the mast crane beside it) and check it thoroughly. My hope is that the 2-pot paint holds well.
Recently we did a little repair job on the deck of a GRP boat, putting on a patch of glass roving. Instead of using polyester or epoxy for resin, we simply used the 2-pot polyurethane paint. This appeared to work brilliantly well, so if I ever am to glass a wooden mast top again, I will use that method and thus avoid the epoxy.
Cheers,
Arne