PS Advisor: 02/15/05

Waxes that Cut?
In past issues, Nick Nicholson, your peripatetic Editor-at-Large, made the point that if you are long-distance sailing, it makes sense to wax regularly and polish only occasionally. He said you don't need the high finish provided by polishing out the wax, which often comes courtesy of a cutting agent. Nick's approach of not polishing out the wax makes sense to me. But will that really make the wax last longer?

I have very happily used auto waxes, including Turtle. My question is this: How can you tell if a wax does or does not contain a cutting agent? I am not confident that manufacturers distinguish between waxes and polishes in a way that would be useful for preserving gelcoats. Is there an answer to this one?

Ian Jenkins
Valdivia, Chile

On the subject of keeping fiberglass gelcoat looking new as long as possible, PS has over many years exhaustively tested cleaners, waxes, polishes, bleaches, compounding agents, and stain removers, etc. The objective always has been to keep the gelcoat clean and shiny.

Needless to say, one of the keys to preserving that new look of gelcoat is to not let it get dirty and stained. Basic to this pursuit is a good coat of something that precludes dirt from getting into the pores of the gelcoat. This is especially important as the gelcoat ages and loses its slick surface. We call that process "chalking."

(If you fail to protect the gelcoat and then decide you want it spiffed up, you'll need harsh cleaners and even compounding paste to get it clean. In the process of this extreme treatment, you'll be unavoidably damaging the surface of the gelcoat, by removing some material. Once you get the best possible result, wax it.)

On a well-maintained boat, PS has found that the ordinary household cleaner Fantastic does a good job. Because it has a slightly foaming action, it needs just a bit of time to work well. Apply it to a three-foot square, move on and do another square, then go back and wipe the first one clean with an old white towel. Along with any dirt you've picked up (the previous wax job should have made it difficult for dirt and stains to stick), you should see some yellowing on the towels, which is the remnants of last year's wax.

For stubborn diesel exhaust stains under the counter or those weird stains along the waterline or stains from that brown canvas tarp you used as a winter cover, it may take two or three applications of Fantastic.

When the hull is clean, you might rinse it with fresh water and let it dry.

Next comes the important step. Apply a really heavy coat of paste wax, allow it to dry thoroughly and polish it out. Everytime PS has tested waxes, Collinite has come out on top. It's a wax favored by private airplane owners. Don't stretch the wax. Apply it so thickly that it leaves visible ridges.

It's not hard work to smear it on, but what comes next is.

If you want the hull to shine, polish out the wax, again with old towels. (If you live in an area where waterline stains are common, put another quick coat of wax along the waterline.)

Once done, you're set for a season of sailing in northern climes. (If you live in the tropical zones or use your boat a lot, beat up the hull on pilings or have a high-speed boat, you might be doing this twice a year.)

All PS knows is that, if kept clean and heavily waxed, gelcoat can be kept new-looking for 10 to 15 years.

We've done it.

Now, for Reader Jenkins' question, will the wax last longer if not polished out? The answer: Yes. (We do that on a portion of the kitchen counter that gets heavy usage. The unpolished wax lasts maybe two or three times longer—because you haven't removed some of it by polishing.)

So, for long-distance sailing, leave the wax dull; If you want to put on a show as you enter that gorgeous harbor at Grenada, stop outside the entrance, launch the dinghy, and polish out the hull.

How do you tell if the wax contains what Reader Jenkins calls a "cutting agent," also called compounding, rotten stone, or whatever? Beware of any product claiming to be a "cleaner wax." If it's pure wax, it should say so on the container, of course. But we always test. The grit can be detected by taking a tiny smear on a finger, then rubbing back and forth. If there is any grit in the wax, you should be able to feel it. If you're still in doubt, find a piece of clear plastic, maybe a soft drink bottle, rub it hard with the wax, wash it in strong detergent and see if you can detect any scratching. Those are the best methods we've contrived for determining if a wax contains "cutting agents."

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