canvas waterproofing

My Sunbrella canvas top is allowing lots of rain to soak through in to the fly bridge. Any suggestions for a good waterproofing product is appreciated.
Thanks Bert

303 works well but you should clean the canvas thoroughly using a cleaner made for cleaning and prepping the canvas for the 303. Nothing will seal the canvas permanently but 303 does as good a job as anything else.

Many around here use the plain Thompson's water sealer you can buy at a big box store.

The first 5 years or so I would only use what sunbrella recommends to maintain...but after that or the orginal waterproofer is gone...the Thompsons works great and is recommended by several canvas people around here with the same recommendation I gave.

Test is you have a very light color...but on all the darker shades it dries and you never notice it.

I tried the Thompsons and didn't like how it worked for me - it didn't last song and smelled pretty bad. It also put a coating on the deck alongside the dinghy after a couple of rains. It was used on 5 year old Sunbrella. Since then we've only used 303 and the results are great. The stuff is somewhat expensive but it's easy to apply and works. We try to coat everything well once a year and touch up as needed.

Living in 150 plus inches of rainfall each year requires some serious waterproofing. I have found a product called 'Dry Camp' heavy duty level, is working well for my fly bridge chair covers. I use on my 'carhart' coveralls, golf jacket, cotton coveralls. Yes, after washing the clothes require a new spray. I believe the product manufacture is Coleman, away from home at the moment so I can't look at the can.
Would post a photo of our boat, but just not technically up to speed. Still have a cell phone with a rotary dial!
A.M.Johnson
27' Marben trawler
'Hapi'
Ketchikan, Alaska

Several years ago I used a "Starbrite" waterproofing product on 1/2 our cockpit canvas. It is still beading well, while back 1/2 is dripping water thru canvas. Product was sold thru West M. Sorry I can't remember name.

I have used both 303 and Thompson's on my Sunbrella. I think the 303 worked a little better but by the time I tried the Thompson's my Sunbrella had many years on it and was noticably thinner than new. My sunbrella get fairly dirty from airborne dust. I wash it in a laundry mat washing machine and it comes out looking like new. But the caveat is that residual soap left in the canvas really aids it leaking. I rinse it at least four cycles after washing. Using a front loading washing machine you could still see evidence of suds after three rinses. After washing I spray it with water proofing.

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Sunbrella: Marine tops and covers