Strengthening a Wooden Boat Mast

Considerations on using epoxy to reinforce an old mast, and why not to paint it. October 19, 2006

I currently have a project restoring a sail boat with a wooden mast. The mast has no sign of rot in it and I would like it to be saved. The downside is it has been exposed to the weather for a few years. The varnish has all deteriorated and the laminated sections in the mast are showing as cracks. I was wondering if these cracks can be filled with an epoxy, sand the entire mast and repaint it. Due to the flexing in the mast, a recommendation on epoxy type or something better is needed. Any advice on this part of the restoration will be very helpful. Thanks in advance for any input.

Forum Responses
(Adhesives Forum)
From contributor A:
How wide are the openings of the cracks? That would determine my approach. I spent 15+ years restoring wooden boats and the stick sounds like it's probably salvageable. One more question is, free standing or stayed rig?

From the original questioner:
The cracks are 1/16" to maybe 3/16" max. As for it being free standing or stayed, it is free standing. It sits in the bottom of the boat, not bolted down or anything. It was set in place with a few wedges placed at the top and held down by the lines.

From contributor A:
My only concern is that the wood may have become somewhat brittle with age. If you want to try and fill the cracks use a 1 to 1 ratio epoxy as they tend to be more flexible than a 3 to 1 or a 5 to 1 mix. You could thicken it with wood flour or very fine wood dust. I'd avoid silica based thickener as that seems to make the cured resin a lot harder.

From the original questioner:
It will be two to three weeks before I start filling those cracks. I will see how it blends in using some wood flour in the mix. Hopefully it will be good enough to have it varnished like it was originally. If not, I will have to cover it with paint. Thanks again for the input.

From contributor B:
I agree with the advice you've been given so far. One other item that I noted in your original post was the mention of paint. Is the stick painted now? A mast is not typically painted (I won't say never, but not often). The main reason is that people want to be able to see what's happening with the wood. A mast is a critical component, and breaking one can be dangerous in a variety of ways. With paint, it's too easy to not notice a problem developing.