There is a bewildering range of topside maintenance choices for keeping your boat looking great, or restoring one that’s looking past its best. However, the most obvious (or expensive) options are not always the best solutions.
Single- or Two-Part Paint?
Conventional, single-part marine paints, such as marine enamels, rely on the evaporation of an oil-based solvent to set. Two-part paints, however, work in a different manner. When mixed together, the two elements create a chemical reaction that locks the ingredients into a hard protective layer.
Single-part paints (enamel or polyurethane) have the advantage of being quick and easy to apply, but some of the enamel types can be relatively soft, meaning they are prone to damage from chafe and wear from items such as dock lines, fenders, or anything else that comes into contact with your topsides. Single-part polyurethanes fare better in this respect, but can have less gloss and can sometimes fade relatively quickly when exposed to sunlight.
For more details, watch our video How To Paint a Boat
Two-part polyurethane marine paints tend to have considerably greater scuff resistance than any single-part paint, while some, such as Awlgrip or Imron, are harder than the gel coat to which they are applied. A two-part paint system can last twice as long as a single-part alternative. The downside, however, is that application is more difficult and expensive. The two elements rely on a chemical reaction to cure, so they must be mixed thoroughly and have a limited pot life before setting. In addition, two-part paints, whether primer, undercoat, or topcoat, cannot be applied over single-part paints, as the solvents in the two-part paint will partially strip the existing coating.
Enlisting the Skills of a Professional
A complete topside refit using Awlgrip, Imron, or other two-part polyurethane paints is capable of looking great for 10 years or more, especially if a top-quality two-part paint is used. On the downside, this is an expensive process; you may well be taken aback by the prices quoted if you’ve not already had experience of having a boat resprayed. In addition to the large amount of preparation work needed, part of the problem is that there’s often no alternative to putting the boat in a shed for the work, which entails lowering the mast if you have a sailboat.
Preparation Is 90 Percent of the Job
A significant savings can be had by completing some or all of the preparation work yourself. No paint system is better than the surface to which it must adhere, so it’s vital to ensure the substrate has been faired and sanded to as smooth a finish as possible and that any existing layers of paint are securely attached. Areas of chipped or flaking paint must be dealt with before repainting. Small areas can be removed with a scraper, and the edges of the damage feathered with sandpaper to create a fair finish. Larger areas may need to be stripped entirely.
A high-gloss finish will highlight any imperfections on the hull, so it’s worth fairing it carefully. This inevitably means using a longboard, a three- to eight-foot long sanding board approximately four inches wide that will sand only the highest spots on the hull. Once the hull is mostly flat, any remaining deep hollows can be filled with an epoxy filler, before further long-boarding to achieve a good surface.
For a professional finish, you can then apply a coat or two of high-build primer, before more long-boarding and finally applying a primer in preparation for the final coat of finish paint.
Once the area to be painted is in sound condition, abrade the entire surface with sandpaper to provide a mechanical key for the new paint to stick to. As a minimum, a half-sheet or rotary sander is needed to cover large areas, while a small triangular model will enable difficult corners to be reached.
You can make even greater savings by painting the boat yourself, which need not be a time-consuming process if you are well-organized. Unless you already have considerable experience with using spray-painting equipment, don’t be tempted by this route; it’s a skill that’s more difficult than an experienced operator makes it appear.
Luckily though, spray painting is not the only way to achieve a great finish. An excellent result can also be achieved with two people working as a team. This means having one person apply the paint using a four-inch roller, while the other uses the most gentle of stokes with the tip of a wide paint brush to lay the paint off with vertical strokes. It should be possible to apply a coat to each side of a 30-foot boat in around 60 to 75 minutes using this method. Once the paint has hardened for a few days, a few hours of polishing with a machine can bring the paint to a finish almost as good as a professional respray, without highlighting as many imperfections in the smoothness of the hull as a respray.
For more, watch our video How To Paint a Boat.
Polishing and Sanding: An Easy Alternative?
Aggressive advertising campaigns by paint manufacturers resulted in many boats being painted in the 1980s and 90s, when a simple polish would have restored them to an as-new shiny finish that’s more scratch-resistant than all but the most expensive paint systems. The same holds true today, in many cases.
Polishing can still be a viable proposition, even for boats with topsides that have faded due to sunlight (although some may need to be sanded with very fine abrasive paper before polishing commences). The ideal tool is a random-orbit sander, such as one of the Fein or Bosch series, which are available from professional tool shops. A key advantage is that these machines can use much finer grades of paper than do-it-yourself grade sanders.
Badly faded colors may benefit from sanding with paper as coarse as 400 grit, but in general 640 is a safer starting point. Follow this with 800-grit discs. By this stage, white gel coats will already have a shine, although dark colors will gain a much deeper shine if you then sand with a 1200 grit paper, before polishing.
Topsides that are polished every year or two won’t need sanding, but using a polishing head on the sander and rubbing compound will rapidly restore the shine. Finishing the job with a wax compound helps to repel dirt and grime, as well as offering protection against ultraviolet sun damage.
For more details, watch our video: How To Restore Faded Gelcoat.
Wrap It Up
Ever see a van or other vehicle riding down the highway with colorful advertising images seemingly “painted” on the entire body of the vehicle? These vinyl wraps have the potential to be a quick, inexpensive and surprisingly long-lasting alternative to a professional respray on boats. Benefits include significantly reduced preparation time and quick application, which helps to both reduce costs and minimize the time during which the boat is out of action.
Although they are a relatively recent development, there are now plenty of examples that have lasted some four to five years without problems. In addition, specialists have developed techniques to repair dings and scratches without replacing the entire wrap.