Although we’ve tackled our share of varnish with a heat gun and scraper, we’ve never used them to strip bottom paint. The obvious concerns would be marring the gelcoat and the noxious fumes created by heating paint solvents and active ingredients. Our first choice for removing antifouling would be sodablasting (PS, October 2011), but as that’s not an option for you, we’d consider chemical stripping (PS, April 2008 and March 2009), wet-sanding, or vacuum sanding.
We recently launched a new evaluation of marine adhesives and sealants. There is no single caulk that works in all of these cases, so its impossible to declare a single Best Choice adhesive, but we decided to at least put some numbers on paper to guide you in your choices.
When deciding on a process for clearing antifouling paint and coatings off the bottom of your boat, first define your goals and try to be as minimally invasive as possible. If your boat bottom needs more than a scrubbing but less than a full peel, sodablasting is a technique that will strip bottom paint but leave gelcoat intact. The unique softness of the calcium carbonate powder in sodablasting is effective, and the tented setup keeps the old coating contained. This report outlines the sodablasting process, calculates the cost in time and money, and compares its performance and cost-effectiveness to other bottom-stripping techniques we've tested.
My pal Jimmys inflatable dinghy sprung a leak. It was a simple repair. He hoisted the boat aboard, put a wire wheel on his cordless drill and began scuffing the surface in preparation for gluing. Seconds later, a two-inch strand of wire had pierced his cornea and he was on the way to the Northern District Hospital in Luganville, Vanuatu. After battling infection for several weeks and follow up treatment in Australia, he got most of his sight back.
While many potential failures are easy to spot, some flaws are hidden under paint or within the structure, or are so small that a routine visual inspection won't pick them up. Standing rigging, hulls, decks and hardware fittings are the most common places where hidden structural weaknesses can lead to big repair bills, or even loss of life.