Endorsed by Sunbrella, the water-based polymer features UV protection and waterproofing. Buy now
Coverage per container: 75-100 sq. ft. (16 oz.)
Cost per square-foot coverage: $0.10 (gal.); $0.16 (16 oz.)
Water Beading: 3/3
Water Column: 3/3* (*14 inches)
This water-based liquid concentrate is safe for the environment with no heavy solvents and is safe for humans and pets.
Coverage per container: 250-300 sq. ft. (16 oz.)
Cost per square-foot coverage: $0.11 (16 oz.)
Water Beading: 1/2
Water Column: 2/3* (*5 inches)
This neutral-colored, polymer-based treatment is designed to create water resistance while letting the fabric breathe.
Coverage per container: 600 sq. ft. (gal.); 150 sq. ft. (32 oz.)
Cost per square-foot coverage: $0.07 (gal.); $0.14 (32 oz.)
Water Beading: 1/3
Water Column: 1/3* (*2 inches)
This UV-protective fabric waterproofing won’t change fabric color, and PTEF polymers repel stains. Buy now
Coverage per container: 465 sq. ft. (gal.); 80 sq. ft. (22 oz.)
Cost per square-foot coverage: $0.11 (gal.); $0.31 (22 oz.)
Water Beading: 2/3
Water Column: 3/3* (*7 inches)
This spray provides UV protection in a nonpetroleum-base product that’s safe for the environment, so it’s safe to apply around water.
Coverage per container: 465 sq. ft (gal.); 80 sq. ft. (22 oz.)
Cost per square-foot coverage: $0.11 (gal.); $0.31 (22 oz.)
Water Beading: 2/3
Water Column: 2/3* (*4 inches)
This UV-protective fabric waterproofing won’t change fabric color, and PTEF polymers repel stains.
Coverage per container: 465 sq. ft. (gal.)
Cost per square-foot coverage: $0.12 (gal.)
Water Beading: 2/3
Water Column: 3/3* (*8 inches)
Even the best marine canvas loses its ability to shed water over time. For a boat with 12-month exposure to the weather, refreshing its waterproof surface is a good annual project. For boats that spend most of their downtime under roof or shrink-wrap, two to three years is a wise interval before reapplying waterproofing. What works best? BoatingLAB challenged the top six fabric waterproofing spray brands to show their stuff.
How We Tested
Our test platform was a Markham coated-fabric mooring cover. Eight years of Florida sun had faded it and made it leaky, but its fabric and stitching remained sound. Before testing our products, we scrubbed the cover with a stiff brush and detergent and then pressure-washed it using a wide, nonabrasive fan-spray pattern. We scrubbed it again with an oxygen-based mildew cleaner. After it dried we brushed it and then used a leaf blower to remove all accumulated dust. Dirt and dust left on the cover or trapped in the fibers serve as a conduit to water.
Treating the Fabric
We stretched the fabric over a 2-by-10-foot table and marked off a 2-square-foot test area for each product. Using a garden sprayer, we misted each section of fabric with a different product, first in a crossed diagonal pattern and then, after drying, in a vertical-and-horizontal pattern.
Water Beading Test
Water should bead and stand on a fully waterproof fabric. We tilted the table 2 inches across the width. We misted the untreated fabric with a hose from 4 feet away, allowing the water to fall like rain. After the test area was fully wetted, we observed absolutely no beading, indicating a complete failure of its waterproofing agents. No surprise there after eight years. This was our baseline, and the test would be conducted again after treatment. Our scoring system for this test was:
Good = 1 point
Better = 2 points
Best = 3 points
Water Column Test
Fabric makers test waterproof status by standing a column of water on the fabric. We added water until it leaked, requiring it to hold the water back 10 seconds before six drops appeared on the underside. The same scoring system was used:
Good = 1 point
Better = 2 points
Best = 3 points
Color Shift
While all test products darkened the treated fabric slightly, we did not find it to be objectionable. We thought it was noteworthy but not a point of concern for users.
