Best finish for an old wooden sneak boat

by Stacy Leon
(Ann Arbor, MI)

I am refinishing an old Lake St Clair sneak boat made with 5/8 in mahogany planks that are for the most part very tight.

The keel / plank connection has a decent gap of about an 1/8 in.

One plank on each side is some how warped and has a large gap of almost 1/4 in.

I want to try to tighten down these two warped boards as they do have screws.

I thought to then caulk with cotton and top it off with putty and paint the hull.

The style of boat can be seen here:

Some history for the boat is that it was fiberglassed.

I was able to remove 5-7 layers of poorly applied glass/epoxy/polyester/paint combinations to reveal the beautiful mahogany hull.

With some effort the glass peeled off like an egg shell.

Can I get any advice on cotton caulk, putty and paint?

I do not see antifouling paint as being the correct application here as the boat will not remain in the water for long periods.

Although may need to remain in the water for a while so that it does not leak.

It would be cool to keep a clear finish on the mahogany but that may not be practical.

Thanks for any help.
Stacy Leon

Comments for Best finish for an old wooden sneak boat

Click here to add your own comments

Apr 11, 2024
Sneak Boat Finish
by: Ai

Hi Stacy,

Sounds like a nice project. Here are some thoughts on your various points:

1. Tightening down the boards: Be careful not to split the boards by over-tightening the screws. For the best results, I would recommend using a combination of adhesives (like marine epoxy) in conjunction with the screws to secure the planks.

2. Caulking with cotton: It's a traditional method that has been used for centuries and it works well if done correctly. However, make sure the planks are dry before you start the caulking process. Also, pushing the cotton too far into the seam can starve the caulking and create a weak point in the seam.

3. Putty: Marine-grade putty would work well in your situation. Look for a flexible putty that will move with the wood during temperature and humidity changes.

4. Paint: As for paint, if the boat isn't going to sit in the water, you probably don't need antifouling paint. Instead, consider marine-grade topside paint that provides a hard, glossy finish. It's tougher and more water-resistant than regular paint.

5. Clear finish on mahogany: It certainly would be beautiful but maybe not practical in the long term because clear finishes (like varnish) tend to be less robust than paint and it may not last long with the structural movements of the planks. But if you decide to go this route, ensure you get a product with UV protection.

Remember, preparation is key. Make sure every surface is clean, dry and sanded before applying anything. And also remember every boat, like every project, is different, so please make sure my advice fits your situation.

Wishing you smooth sailing on your project,

Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Questions and Answers Forum.

Want to add more photos?

Photo Uploader

If you are having problems uploading Photos or would like to add more click on this link for the Upload Form.

Show / Hide