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Thread: Sunbrella waterproofing

  1. #1
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    Default Sunbrella waterproofing

    So, I have this Dovekie with sunbrella canvas/hatch covers. I was under the impression that stuff was water tight. I was definitely wrong. Would I be a fool to coat it all with Scotchguard, or is there something better? Other than beeswax.

  2. #2
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    Default Re: Sunbrella waterproofing

    303 Fabric Guard is the proper stuff to proof Sunbrella. You can get it from Amazon if not locally. Don't mix different types of treatments as it often makes things worse and coverage spotty as they fight with each other. Sunbrella when treated is highly water resistant, but still breathes (which for boat covers in general is usually at least as important as it prevents mold). For hatch covers you might want something coated or laminated to make it actually water-proof if the normal Sunbrella fabric won't do the job - Top Gun, Sunbrella Plus, Weblon vinyl-coated nylon, etc.

  3. #3
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    Default Re: Sunbrella waterproofing

    How long does a dose last Todd? Is Scotchgard painted on?

  4. #4
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    Default Re: Sunbrella waterproofing

    Thanks, Todd. I've seen that stuff on Amazon, the description struck me as kind of vague but it sounds like the right stuff.

  5. #5
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    Default Re: Sunbrella waterproofing

    How long does a dose last Todd? Is Scotchgard painted on?
    Scotchgard isn't used, Fabric Guard is the right stuff. I suppose the lifespan of the treatment probably depends to some extent on the amount of UV the cover gets. At Midwestern latitudes I usually re-treat my covers every couple of years. In very sunny climates, I'd probably do it each spring. The treatment both refreshes the cover's water resistance, and 303 Fabric Guard is additionally just about the best UV blocker refresher for fabric you can buy. Properly treated, your covers will both work and last better.

    My wife washed the Sunbrella cover for the Whaler yesterday. She used warm water, a soft brush and Dawn Ultra dish soap and scrubbed it spread out on the deck. It really came out clean and any yucky spots were pretty much gone. After a really good rinse we let it dry and I ordered a fresh bottle of Fabric Guard. It comes as a pump spray which works, but can be tiring for your hand when spraying a whole cover. I pour some into a cheap Harbor Freight HVLP gun and spray it instead (wearing a good mask, as coating the inside of your lungs with that stuff is likely a bad idea).

    There are both 303 Protectant (like Armorall for rubber, vinyl, etc.) and 303 Fabric Guard for cloth goods). Incidentally, nearly all windbreakers, raincoats and other outdoor clothing items are finished with a fluorocarbon water resistant treatment at the fabric finisher. Even rain or foul weather gear, which may be coated or breathable like Gore-Tex, have this sort of treatment on their outside surfaces. These fabrics work even better if you limit the amount of water that is even getting down to their coatings. Fabric Guard is the same sort of treatment and is compatible with the original substance that came on the item. Other treatments (silicone sprays, for example) probably are not.

  6. #6
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    Default Re: Sunbrella waterproofing

    Quote Originally Posted by Todd Bradshaw View Post
    Scotchgard isn't used, Fabric Guard is the right stuff.
    My mistake, thanks for the info.

  7. #7
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    Default

    I wish I had a way to remember all the good stuff I read on here. Particularly Todd's recommendations on anything to do with sails and boat fabrics and painting and glassing.

    Sent from my CPH1851 using Tapatalk

  8. #8
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    Default Re: Sunbrella waterproofing

    Quote Originally Posted by lupussonic View Post
    How long does a dose last Todd? Is Scotchgard painted on?

    No Scotchbright, but 303 will last most (if not all) of the New England Summer. if you boat is in longer plan to refresh it mid-season.

  9. #9
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    Default Re: Sunbrella waterproofing

    I have been meaning to find out how to improve the water resistance of my Weathermax boat tent (like Sunbrella). Just ordered the 303 Fabric Guard on Amazon, thanks Todd!

  10. #10
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    Lightbulb Re: Sunbrella waterproofing

    PS: If you are patient enough, the seagulls and boobies will coat the sunbrella fabric with a liquid-like substance which will set absolutely rock hard.

    It may not be evenly applied, but may require a power washer to remove it.

    It will have whitish light grey color, that will provide insulation and also reflect heat.

    Advantage is that the coating will continue to be applied free-of-charge for life.

    DAMHIKT
    I live and drink rum where other people vacation.

  11. #11
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    Default Re: Sunbrella waterproofing

    I'm currently using 303 on sunbrella but have used lots (gallons) of Scotchgard on sunbrella with same results. I normally brush it on and fill the weave, which consumes more than you would ever want to apply with a trigger spray bottle. I've mixed the two on the same awnings and seen no difference, water proofing, blotching, color retention, etc...except the 303 is more expensive. How long it lasts totally depends on where you are, exposure and how much you saturate the fabric.

  12. #12
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    Default Re: Sunbrella waterproofing

    Make sure your sure that your Sunbrella® is really clean before trying to waterproof it.
    I live and drink rum where other people vacation.

  13. #13
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    Default Re: Sunbrella waterproofing

    303 Fabric Guard per Sailrite's website = water repellent, not waterproof on basic Sunbrella


    • Fabric protector spray that strengthens and restores lost water repellency for marine fabrics
    • Safe for outdoor synthetic and natural fibers in marine environments
    • Protects against both water-based and oil-based stains
    • Does not alter fabric color, feel, flammability or breathability
    • Recommended by Sunbrella®, leading outdoor fabric manufacturer
    • Superior stain resistance & soil release characteristics
    Cheers
    Kent and Skipper
    Small Boat Restoration blog

  14. #14
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    Default Re: Sunbrella waterproofing

    Just did my Dovekie's canvas with 303. Seems to work beautifully. Sprayed the pieces with the hose today and the water beaded up as if off a fresh wax job. However. I ordered the spray bottle, which claimed it was good for 75 square feet. The directions tell you to saturate the fabric. The bottle has two spray settings, one is a kind of a gentle mist, the other is a more aggressive spray. the mist did not discernibly wet the fabric so I used the other one. I managed to saturate all of about 25 sq. feet before it ran out. I got the hatch covers and the forward hood anyway, so I at least won't be sleeping in a drip (I hope)...

  15. #15
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    Default Re: Sunbrella waterproofing

    It's been about two weeks since I sprayed the cover for our 1975 Whaler, and it took about 2/3 of a quart bottle of Fabric Guard through my HVLP spray gun. I gave it a pretty heavy misting, but was not really trying to saturate the cloth. One nice thing about the gun is that you can get really even coverage. It's been raining like crazy this month and as far as I can tell, the only water intrusion has been about two tablespoons that seem to have come in where the support poles pass through their grommets up top. During a heavy rainstorm the cover will look wet, and water isn't beading up and rolling right off, but none seems to be getting through.

    No, I didn't make this cover (I hate making boat covers) but it's nicely done and looks to be maybe 8-10 years old by the fabric's softness.

    BW3.jpg


    A test I once did on two small hunks of Egyptian Cotton sailcloth - one plain, one sprayed with Fabric Guard. This was about fifteen minutes after pouring a little water on them. The untreated cotton soaked up the water instantly. Most of the water poured on the 303 sample just ran off onto the counter. Before wetting them, the two pieces looked and felt the same.

    303-test-002a.jpg

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