Gel coat oxidation

You might have a lot of folks tell you that you can get away with using one-step waxes and snake-oil treatments that guarantee a great shine, but the truth is, if you have a badly oxidized gelcoat finish, the method you’re going to read about here is exactly how the pros would do it if you hired the job out yourself. It requires some specialized tools and materials, but you can save a good amount of money doing it yourself. If you have light or moderately oxidized gelcoat, have a look at this video, which explains the steps in removing that light oxidation from your boat.

Tools of the Trade

The first step in any gelcoat restoration job is removing that layer of oxidation standing between you and a good shine. And if that oxidation is heavy, I’m not going to lie to you—only a machine will get it off. You can use a household electric drill with a retrofit buffing pad if yours is a small project, but if you need to compound anything over 20 feet, a seven-inch angle grinder with the correct buffing pad (3M’s Superbuff is a good one to try) is the tool to get. Expect to pay around $200 for a good-quality one, or you can also usually rent them for around $30 a day from a tool rental shop.

Getting Started

Before we get started, we’ll assume your boat is out of the water or on a trailer, because it’s virtually impossible to restore a faded gelcoat hull while a boat is in the water. (If you’re just working on the decks and interior portions of your boat, you can certainly accomplish that while the boat is floating.)

First, give whatever gelcoat surface you’ll be compounding a good wash, and then let it dry. If it’s especially dirty, use a heavy-duty cleaner such as Krazy-Klean or On and Off. Once you’ve gotten the dirt out of the way, it’s time to break out the rubbing compound and machinery.

Compounding

The first step in the process involves using rubbing compound, which is generally a mineral-spirits based liquid or paste with fine abrasive particles suspended in it. When you “rub” in a rubbing compound (or polish it in with a machine), it slowly removes all of that nasty gelcoat oxidation from the surface. Do it long enough and you polish in a dull shine. The objective in this step is not to get a high-gloss shine, but to remove all of the oxidization and prep the surface for a finer polishing. Now, if your gelcoat is scratched or gouged, you’ll want to make those repairs before getting started.