canvas waterproofing

I am considering using Thompson waterproofing on my fly bridge sunbrella canvas.
Has anyone used this product and what results did you have?
Thanks for your responses
Bert

Fabric Guard 303 is the product recommended by the manufacturers of Sunbrella - it restores the water repellent properties of the fabric, and enhances the UV protection. Available at Jamestown Distributors, Sailrite & lots of other outfifts - just a satisfied user.

Try a search for "thompsons waterproofing flybridge canvas" a few months ago I was thinking of doing this I found so many differing opinions that it is; good, terrible, recomendations for other products, etc. I haven't been able to make up my mind which to do. I may try 303 applied with a roller.
If you find and experience a good solution let us know.
Steve W

I tried Thompsons on my cedar deck at home and it did not work very well there.

The 303 is a spray bottle like 409. Just lay your bimini out and start spraying. Easy breezy. No roller needed.

I have applied it a few times with the sprayer bottle it comes in I didn't find it very effective. I recently read this review online and figured it might be worth trying.
I'll try with a thin map roller.
Steve W

"A canvas maker turned me on to this product. My dodger and bimini are 12 years old. This delays the inevitable replacement by adding a water proofing element. Need to put on every year for best results. Canvas maker told me to use a small paint roller and a paint tray. Pour the liquid in the tray and roll on. Gives much better application than spraying (do not recommend spraying...it does not go on well and you lose product into the wind). The last two seasons I brought my dodger & bimini home and laid out the fabric in the garage on a plastic paint sheet. I applied the 303 heavily with the roller and let it dry overnight. Once it is dry you would never know you put it on (my fabric is midnight blue). I really like this product."

xfedex said:

I tried Thompsons on my cedar deck at home and it did not work very well there.

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Years ago I read a Consumer Report article on deck treatments and Thompson's was not at the top of their list.

As for using it on canvas or Sunbrella, I think it would be foolish to use a product intended for wood when products designed for canvas and Sunbrella are readily available. The Sunbrella website has instructions for caring for their product including waterproofing.

Sunbrella: Marine tops and covers


In my mind, using deck waterproofing products on marine canvas is just another of the "stupid boating tricks" perpetuated by boating forums.

I have tried Thompson's on 10 year + Sunbrella. I have also used 303 both prior to and after the Thompson's. The 303 works better albeit at 4 times the cost. But even at that the cost of the 303 wasn't a factor. The Thompson's worked but the result was not 100% effective. My Sunbrella was pretty worn at the time I used it. I could not find any harm from the Thompson's. The color might have darkened slightly. There was no runoff stains on the fiberglass as I feared might happen. The Thompson's might have faired better if my Sunbrella were newer. After the Thompson's trial I went to the Starbright waterproofer 303 equivalent. Not much better than Thompson's but better than nothing. After that I returned to 303. The 303 is definitely the superior product.

Thompson's is parrafin wax dissolved in a solvent. If you Google around enough, you can find the formula. I had it once, but misplaced it. I too use 303.

Do not Use!!!!!!! I used it a few years ago and it melted the stitching. Had to have it all resewed.

hammaarn said:

Do not Use!!!!!!! I used it a few years ago and it melted the stitching. Had to have it all resewed.

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Is it possible that the stitching failed from exposure to ultra violet light from the sun, rather than from the waterproofing product?

I'm not going to suggest that any one use deck sealer on marine canvas (see my post above), but unless the very best thread was used originally, the stitching usually fails well before the canvas and it's common to have these products restitched once or twice over their lifetimes.

I have restitched all my canvas and have never used deck sealer on it.

I use H&B Dabond 2000 UVR polyester thread on everything I stitch. The Sunbrella will fail before the thread. I also use V92 and V138 for everything (nearly dental floss size) so it's heavy stuff.

I doubt that anything in 303 is 'melting' thread. It would 'melt' the Sunbrella equally well.

lots of people use and recommend Thompsons Water Seal....best product for the job? Probably not but it's inexpensive and readily available. results may vary widely based on user, application, and product selected.

On my Tonneau cover, over the flybridge, when parked in outside moorage, I tried Thompsons on one half and nothing on the other half. Thompsons worked to make that half much more waterproof, and did not damage the stitching. It didn't last long, so by the next winter there was no difference between halves. The Sunbrella was old and thin at the time, and was replaced within a couple of years, so no further experimentation was done.

koliver said:

On my Tonneau cover, over the flybridge, when parked in outside moorage, I tried Thompsons on one half and nothing on the other half. Thompsons worked to make that half much more waterproof, and did not damage the stitching. It didn't last long, so by the next winter there was no difference between halves. The Sunbrella was old and thin at the time, and was replaced within a couple of years, so no further experimentation was done.

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That's pretty much the results that I have had and have been reported to me from friends and nearby boaters.

Thanks all for your input. 303 seems to be the way to go
Bert

303 Fabric Guard.

I use a pump up garden weed sprayer that has an adjustable nozzle from a stream to a fine spray. it holds about 1/2 gallon and does a far faster, better job than the hand sprayer and it saves the fingers.

C lectric said:

303 Fabric Guard.

I use a pump up garden weed sprayer that has an adjustable nozzle from a stream to a fine spray. it holds about 1/2 gallon and does a far faster, better job than the hand sprayer and it saves the fingers.

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I use the same approach with a 2 gallon sprayer for applying water proofing to my decks. Turned 2 days of drudgery into a 2 hour walk on the deck