Ask Sail: Wax-on Poly Paint

I have built a 33ft Kelsall-designed catamaran with vacuum-bagged cored composite panels. I finished the exterior with International’s two-part Perfection polyurethane paint (in white)...
Author:
Updated:
Original:

Julien Cloet from Montreal, Canada, asks:

I have built a 33ft Kelsall-designed catamaran with vacuum-bagged cored composite panels. I finished the exterior with International’s two-part Perfection polyurethane paint (in white). Last year, to improve the boat’s looks and to make it easier to clean, I applied 3M Scotchguard liquid wax to the hull topsides. One month later, after a few rainy days, the hulls were covered from stem to stern with long vertical black streaks that I can’t wash off. Any suggestions?

Don Casey Replies:

Manufacturers almost always discourage waxing linear polyurethane (LPU) paint. The paint does not need a protective coating, and its surface is slicker and harder than wax. The waxed surface is more likely to attract dirt, which, when moisture is added, creates the black streaks you’re seeing. Softer liquid waxes tend to be most susceptible.

DonCasey

You need to strip off the wax with a strong detergent and perhaps a solvent. The bare Perfection paint will better resist streaking; you can help it by washing the boat frequently. If the paint is beginning to lose its gloss, applying a polymer sealer such as Awlgrip Awlcare should give better results than wax. Some boat owners buff an aging polyurethane finish with an ultra-fine polish like 3M Finesse-It II Finishing Material. This cleans rather than coats, but it also cuts the hard surface of the polyurethane paint, and therefore is only suitable late in the life of the finish. 

Got a question for one of our experts? Send it to sailmail@sailmagazine.com

Related

QuarterdeckBuildingWatercolor

Bitter End Yacht Club 2.0

Amid the widespread devastation caused by hurricanes Irma and Maria when they swept across the northern Caribbean in September 2017, the destruction of the iconic Bitter End Yacht Club on Virgin Gorda in the British Virgin Islands was particularly keenly felt by sailors. The ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell. Got a tip? Send it to sailmail@sailmagazine.com The back door Satisfied with your headsails? So was I, until one day I took a long, hard look up the luff of my genoa, making sure I inspected the leeward side as well. The sail had plenty of life ...read more

02-Lydia12-01

Losing Sight of Shore

I arrived on the docks of Beaufort, North Carolina, in late April with two backpacks filled with new gear—everything I’d need for my first offshore passage. Though I’d been sailing for 16 years, graduating from dinghies to keelboats to a J/122, I’d spent my time racing and, in ...read more

Squall

The Face of a Squall

They are the worst of times, they are the best of times There’s a fabulous line from an old Paul Simon song that I often sing to myself while sailing: I can gather all the news I need from the weather report. It is part of the magic of sailing, this ancient process by which we ...read more

ntcktshtrstk

Cruising Southern New England Waters

One of the most wonderful childhood vacations I can remember was back in 1971 when my best friend invited me to his family’s summer home on Nantucket Island. For a 10-year-old kid, this was a thrilling trip for many reasons, not the least of which was the fact it was also my ...read more

IMG_8287GR16Mykonos

Cultural Charters: Mykonos

In last month’s column, I covered the amazing mix of cultures that have called the Dalmatian Coast home over the centuries. Croatia cruising is like a smorgasbord of intertwined centuries, and the islands are a movie set. A little farther south, though, you’ve also got Greece, ...read more

cookinglead

Cruising: No Oven? No Worries

Many cruising boats, especially smaller ones, don’t have a conventional oven. But that doesn’t mean that you can’t have all the baked foods you want, from bread to brownies to breakfast rolls to casseroles and even a roast chicken. All it takes is the right bit of gear and a ...read more