PS Advisor April 1, 2005 Issue

PS Advisor: 04/01/05

Crinkly Varnish
I recently varnished our saloon table and a few shelves. First, I washed everything thoroughly. Then I sanded lightly; then vacuumed repeatedly to make sure the surface was pristine. After a final wipe with a tack cloth, I applied the varnish quickly—dip, spread quickly, wipe both sides of brush on the edge of an empty can, dip, spread, wipe brush, etc…all exactly as Practical Sailor has over the years taught me to do.

It turned out like glass, except for a few small spots, which were crinkled—or what I think the industry calls "alligatored." What went wrong?

Boddy Spencer
New Orleans, LA

In the old days, you didn't mix or stir varnish for fear of introducing air bubbles, which were difficult to brush out. It led to a lot of extraneous brushing, and the problem of bubbles and brush marks got worse as the varnish started to skin.

Most varnishes now are complicated and polymerized mixtures of natural and synthetic resins, drying oils, flatting out agents, viscosity controllers, etc. Some makers want you to handle their varnish gently (like home-brew beer) and use it right out of the can. Others tell you not to shake or stir "vigorously," but don't explain exactly what vigorous means. Some don't say either way.

With some, one ingredient might settle out to the bottom or rise to the top, and it is this that probably caused the problem you encountered. We've had the same experience about a half dozen times in the last few years. We still carefully read can directions and go along with whatever instructions there are. However, to guard against any separation of ingredients, we up-end the can two or three times while preparing the surface. With varnish (and paint) on hand, we turn the cans over about once every couple of months to keep the contents mixed. (PS would welcome any manufacturer's contributions on this subject.)


Ozone Machines—Good or Bad?
The sailing press has printed positive comments in recent years on the use of ozone generators, in particular the Quantum Pure Aire products and their use in reducing odors in boats. I purchased a Quantum product for just this purpose. When I received it several family members and friends were very concerned, suggesting that ozone was in fact harmful to breathe.

A search of the web confirmed that the departments of health in Canada, Alaska, and California have all issued warnings against the use of ozone generators. They state that the usefulness of ozone in reducing odors is overstated, that ozone is a lung irritant, and that in higher concentrations it can degrade other materials, such as rubber and paint. Have you any comments?

Bryan Drummond
Halifax, Nova Scotia

After our past reports on ozone generators, we've received and printed letters from readers pointing out health warnings from various agencies, and the fact that high concentrations of ozone are harmful to rubber and other materials. These warnings are certainly worth paying attention to, and we wouldn't second-guess the health experts. However, in our experience, these things actually do a good job at eliminating odors.

It's important to use good common sense. Once an ozone generator has done its job, and the odor is gone, turn it off. Make sure you have good ventilation, which obviously will help prevent the odor build-up in the first place. And most important, work to eliminate the source of the odor.

We bought a Quantum machine last summer and put it in the entryway of our house, which suffers from mold, mildew, and soggy dog smells in the summer. Without a doubt, the machine eliminated those smells, and left the air with a very faint "tangy" smell. When that tangy smell became stronger, we turned the machine off.

Mid-summer, some little critter had the effrontery to perish in an inaccessible spot within the exterior wall there, and the smell was so bad that it was like getting hit with a mallet when you came through the door. Back on went the ozone machine, at max power. Within about six hours the smell was gone, and the machine kept the smell neutralized for the few days it took the decomposition process to move on. Then the machine was turned off again.

So far, the house and its occupants are still intact.

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