Q: John Miess, email@example.com
We are removing the teak deck from a 1972 Swan 43. We will not be putting any teak back on and will be looking to apply nonskid and paint. I have taken all the fixtures off and removed all the old teak. Now we have black gooey stuff everywhere that I have not been able to remove. I talked to the yard where the boat is stored, and they want to try to grind it away, but I really don’t like the idea. Are there any other means to removing this mess?
Don Casey Replies
That black goo is likely an oil-based mastic, given the vintage of your boat. There are a number of mastic removers on the market that will dissolve old mastic into a liquid that you essentially mop up. But you have to be cautious that the remover will not also dissolve the fiberglass. I would try a soy-based product, perhaps the one manufactured by Franmar called Bean-e-doo. I have no first-hand experience with this product, but have seen reports from other boatowners that it works well. The bad news is that it will still be a dirty and demanding job. You have to keep the mess away from everything you do not want it on, you have to absorb up the oily residue, and you have to thoroughly degrease the stripped surface (probably with xylene). You will also need to seal all screw holes before you start, as letting this oily mess penetrate the porous core material would be a disaster. The good news is that there could be an easier way. Nautor/Swan is a cradle-to-grave boat company, meaning they not only build sailboats, but maintain and refit them. The removal of a 40-year-old teak deck cannot be something they rarely see, so an email to firstname.lastname@example.org might get you reliable information on both exactly what the goo is and how best to remove it.