Keep Your Boat's Gelcoat Glossy

Four experts share their tips for keeping fiberglass boats clean and shiny
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PB_S288_A9_06861

John Benchimol, Harborside Marina

We tell our customers to wax the boat at least every year. You can use any boat wax over the polymer; wax horizontal surfaces often, or any surface that gets a lot of sun. Keeping the salt off is also important. If the shine is gone from gelcoat, the only way to get it back is to compound off the chalked surface and then rebuild it with polish and wax. If the chalking is bad, you might have to wet-sand, but that’s for professionals. Same with stains. If soap won’t remove them, try Magic Eraser. Use On & Off Hull Cleaner on waterline stains, but use it only on the fiberglass hull.

Margarita Xistris, Nautical Details

Wash your boat weekly with boat soap, and remove stains right away. I use eco-friendly products. If soap won’t remove a stain, I’ll try a nontoxic WipeOut Eraser. For tougher stains, use WipeOut Eraser with boat soap or Garry Dean’s Heavy Duty All in One Vessel Cleaner for black soot and pollutants, especially on nonskid. Mean Green Degreaser is another excellent all-purpose cleaner. Whatever cleaner you use, don’t dilute it; apply and let it marinate for 10 minutes. It’s better to use less abrasion and rely on chemical action. For sealing, try Garry Dean’s Bionic Banana Shield.

John Fernandez, John Williams Boat Co.

To remove serious stains, we use On & Off Hull and Bottom Cleaner from Marykate. Some stains can be removed using a home remedy: vinegar. Apply it, let it sit, wipe it off and rinse with water. You might have to do it a couple of times, but it often works. Once the stain is gone, clean the gelcoat with boat soap and water, then restore the shine. We use 3M Marine Finesse-It finishing glaze on a buffing pad. It’s good to use after compounding, say if the gelcoat is badly oxidized or faded. Finally, protect the surface and prevent future stains with a good coat of 3M Perfect-It Boat Wax.

Matt Anzardo, AkzoNobel

The best way to keep fiberglass clean is to paint it. Paint, especially linear polyurethanes, doesn’t have pores like gelcoat, so it’s more stain-resistant, prevents UV degradation and doesn’t need waxing to preserve color. Before painting, take extra care in choosing cleaners. Many hull cleaners contain chemicals that can increase the porosity in the gelcoat. It’s better to use a mild cleaner, even if it takes more effort to get stains out; later, when you’re painting the hull, the technique may reduce the number of primer coats that are used to fill in the porosity.

This article originally appeared in the April 2019 issue.