Originally Posted by Chotu
It seems kind of difficult to find sections of old masts. I have dabbled in this because I have to add 6 feet to mine also. Have you considered having a piece of aluminum bent around to the same shape as the mast?
Just curious what your thoughts are on that.
I have not considered that.. nobody here in this outpost would be able to do that - at least in a manner I might trust (bending alloy can weaken it - you need to know what you are doing I think). Never thought of it.. maybe if you are located where there are talented people who can, if you need help.
What I have considered was a carbon stub. I was all set to do this, and even made the plug
of the inside of the mast in order to make a mold
. The plug
would be for the insert part of the mold
- the part that goes up inside. I made this by laminating a few layers of fiberglass
about 20" up from the bottom of the hull
. Next step would be to lay up glass over the mast and plug to form a mold. This would have to be in enough different sections to be able to remove from the hull
- in my case I would have to make 4 sections due to the shape. In a simple oval, 2 sections would be fine, ending up with 2 half molds. Build in flanges for vacuum bagging the carbon halves, and build in tapers where they join so you can add thickness at the joins.
I was lucky enough to have an engineer
take pity on my predicament and gave me some skin thicknesses I would need for the carbon. It would include layers of uni and some biaxial, and basically meet or exceed the thicknesses of the mast alloy. Any other masts would probably require someone knowledgeable to come up with the engineering. Another consideration is insulating the carbon from the alloy to avoid electrolysis
. I was hoping a few layers of glass before the carbon would work
at the insert part of the stub. I still am considering this, but there's lots to wrap your head
around. I built my boat so am very familiar with vacuum bagging.. but this is a bit above my experience, not having really worked with carbon before.
gave me some plans to build a complete plywood
skin mast which I also considered. Uses a 4mm plywood
I beam with 4mm frames glued to the I-beam with 3mm gaboon (Okoume) ply skins.