Do It Yourself: Marine Paint Removal And Stripping

Marine paints can be stripped using three basci methods: mechanical sanding and scraping, heat, and chemicals. Here is a detailed explanation of each method.

Marine paints are generally the toughest paint finishes available, as they are designed to withstand the ravages of constant sun, wind, and water. This can make them more difficult to remove than other paints but any finish can be removed with the right arsenal of tools and techniques.

There are basically three methods of paint removal available to you to strip the finish from your boat. These methods are: mechanical, heat, and chemical.

Mechanical stripping is the most labor intensive method, but it is also the safest method and might be best for beginners. Mechanical stripping involves removing a finish by sanding it away or by scrapping it away with a variety of paint scrapers. Sanding a paint finish is nothing if not hard, dirty work, but it can be done with patience and plenty of sandpaper. Tools required are one or more power sanders; ideally a random orbit sander, a small finishing sander, and a detail sander for getting into corners and working on small pieces. You will need to start with course sandpaper for the initial removal. The biggest danger of stripping paint by sanding is that you will remove too much material and create a depression in the surface by sanding into the underlying substrate. Avoid this by always keeping the power sander moving. Don't bear down too hard on it or hold it in one spot for long. The other way to strip paint mechanically is by using a scraper. This requires sharp blades and a technique that is perfected with much practice. An expert with a good scraper can peel away a paint surface in short order, but a beginner can gouge wood or fiberglass, or get a serious injury with one careless slip of the tool.

The second method of stripping finish is by using heat. Many professionals strip paint this way, and purpose-made heat guns can be purchased for the job. These heat guns look like an electric hair dryer, but they put out a lot more heat. Using heat to strip paint on a boat, of course, requires lots of precautions. Make sure there is no fuel or other flammable substance nearby before even plugging in a heat gun. The paint is stripped by applying heat in a controlled manner to a small area, then using a scraper or putty knife to scrape away the softened paint. The biggest danger for a beginner is holding the heat in one spot too long and scorching the underlying surface, especially if it is wood. Because of this danger and the possibility of catching your boat on fire, I don't recommend heat stripping the finish on your boat until you have practiced a lot with the heat gun in a safer environment.

The third method of paint striping is the chemical method, and many people might already have some experience with this method if they have ever refinished a piece of furniture. The problem with chemical strippers on a boat is that they can work too well and damage the surface beneath the paint, especially if it is fiberglass. They can also be spilled on areas that don't need stripping and make a big mess. But chemical strippers can be used on a boat if precautions are taken. The first step is to completely mask all nearby areas that you don't want stripped using a heavy duty blue masking tape available in paint supply stores. Select a chemical stripper that is thick, like a gel or paste, so that it won't run or sag if applied to a vertical surface. This type of stripper gives you a lot more control over the job. Chemical strippers might need to be applied more than once on tough marine paints. The key is to give the stripper time to work, then scrape or sand the partially dissolved finish and clean the surface to see if more stripper is needed.

No matter what method you use to remove the finish, the final step is always to clean and smooth the surface with more sanding, using progressively finer grits of 80, 120, and 220-grit sandpaper, depending on what new finish you will apply. Stripping marine paint is nobody's idea of fun, but it's often a necessary step to prepare a surface for fine refinishing.

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