Waterproofing canvas

Haden

Active Member
May 27, 2020
482
Madison, Alabama
Boat Info
2001 Sea Ray 380 Sundancer
Engines
Twin 8.1l Mercury w/V Drives
I spent this week cleaning ALL my canvas. My new 380 came with 2 sets of canvas. A black set with isinglass, and a khaki colored set. Every section has been washed, cleaned, buffed, and some restitched. (My neighbor owns two dry cleaning businesses). Question, what is the BEST product to waterproof the canvas. I plan to use a garden spray for this project. I’m going to lay the canvas out in our driveway and spray. I have been looking at Starbrite waterproofing, Atsko silicone water guard, Canvak, 303, etc. Thoughts please...
 
Starbrite works great... Twice a year in florida to keep it working is what I have found. Garden sprayer and off the boat is the best. Shit gets everywhere. I do it in the parking lot of my marina.
 
I did a thorough cleaning of all of mine this spring. I used 303 Fabric protector this time. I have to say it has worked much better than Starbrite. Starbrite works but 303 is better. Just don’t get it on the isinglass. I used the spray bottles but also a paint brush and tray to do around the glass. No overspray that way. The rain does not soak at all. Total beading.
 
303 is Sunbrella's recommended waterproofing but keep in my mind both companies are owned by Glen Raven. While I like the 303 the Starbrite has worked well too.

-Kevin
 
Another vote for 303. Just did the mooring covers on my day boat and the 13-year-old covers now feel like brand new.
 
I’ve used both 303 and Starbrite and found that Starbrite works just as well for me. Never had any leaks or wicking after treating Canvass with either product.
Then again, it seems like the Canvass gets dirty enough to wash long before the waterproofing needs refreshing.
Come to think of it, I don’t ever remember having to re-waterproof a piece of Canvass for any reason other than having just washed it.
 
Much thanks fellas. That will be today’s project. I live in Madison, Alabama. The next challenge is finding a business with enough of product... haha.
 
I’ve used both 303 and Starbrite and found that Starbrite works just as well for me. Never had any leaks or wicking after treating Canvass with either product.
Then again, it seems like the Canvass gets dirty enough to wash long before the waterproofing needs refreshing.
Come to think of it, I don’t ever remember having to re-waterproof a piece of Canvass for any reason other than having just washed it.

If it is beading it is waterproof if it is soaking the water in it probably isn’t waterproof. Climbed under the mooring cover, during a rain, to see what was going on and water was really coming through the Sunbrella Cover.

I used the 303 On the covers after a thorough cleaning and they now bead very well. The fabric also feels like new. It was interesting to me just how nice the fabric felt after being treated.
 
per sunbrella website/recomendation i used 303. stuff works, HOWEVER, next day after using on my cockpit/mooring cover we came down to boat and found pink stains all over our white vinyl seat. HAD to be the 303, rained heavy that night, must have leached chemical thru cover onto seat. so for now, we are covering the seat with a blue tarp to keep chemical off seat. BTW, 2 days in HOT sun, UV bleached out the pink stains they are all gone. still using blue tarp, for another month to be sure.
 
per sunbrella website/recomendation i used 303. stuff works, HOWEVER, next day after using on my cockpit/mooring cover we came down to boat and found pink stains all over our white vinyl seat. HAD to be the 303, rained heavy that night, must have leached chemical thru cover onto seat. so for now, we are covering the seat with a blue tarp to keep chemical off seat. BTW, 2 days in HOT sun, UV bleached out the pink stains they are all gone. still using blue tarp, for another month to be sure.

The 3O3 says it needs to have about 24 hours to cure before it even gets due on it, much less rain.

Read the label and follow the instructions properly for the proper outcome.
 
I wash my Sunbrella on the boat. Then using a thin foam paint roller and paint pan apply the 303 with the roller using the roller pan. Also using an extendable pole lets me reach all the areas. Alot less messy then trying to do it with a sprayer. Not only do you get more material on, you don't have to worry about wind, and clean up is easy.
Just throw away the roller and pan when done.
 
The most important thing is to wash the sunbrella well and rinse it really well. You don't want any soap or cleaner residue on the material. Then the material needs to be very dry before 303 goes on. I have used 303 before and did not do the full deep clean/rinse and it was not super effective.

I used Captain Phab Awning and Fabric Cleaner for the first time this year. Its really impressive. The muddy water coming off when I used the boat brush to scrub the fabric and then rinse was disgusting. You would not believe how much dirt had ground into the fabric over the years. I thought it was pretty clean and was debating just refreshing the 303 this year. So glad I didn't.

This year, I did it right, and its bone dry. Its been raining all day today. Literally steady rain all day. The canvas, including the slant back without vinyl backing, is bone dry inside and the water is beading and running off outside.
 
Good Reading, I was under my Mooring cover today checking on engine hose part no# ,my arm was touching the cover and water was weeping through, so it needs to get clean and coated .you guy's use any type of special cleaner ? or just warm water and soap with a broom or pressure washer ?
 
FWIW Two 6' ladders with a 32' Extension ladder (in the retracted 16' length) across the top makes a nice giant "saw horse" to lay your canvas over when you are spraying the waterproofing. I use 303 per Sunbrella's direction.
 
per sunbrella website/recomendation i used 303. stuff works, HOWEVER, next day after using on my cockpit/mooring cover we came down to boat and found pink stains all over our white vinyl seat. HAD to be the 303, rained heavy that night, must have leached chemical thru cover onto seat. so for now, we are covering the seat with a blue tarp to keep chemical off seat. BTW, 2 days in HOT sun, UV bleached out the pink stains they are all gone. still using blue tarp, for another month to be sure.

I am not sure that what you experienced came from the 303. It could have come from an interesting problem referred to as "pinking". I ran across this recently with a customer with new canvas and after researching the issue with Great Lakes we were provided this information. It is actually caused by a strain bacteria.

https://www.boatingmag.com/pink-stains-on-boat-seats-fix/
https://gestaltscientific.com/what-is-pinking/

-Kevin
 
OMG. that's it. " along with moisture in a warm environment to rapidly grow." and that night was wet, hot, very humid. and like I said, 2 days exposed to hot direct sun UV light and it disappeared. today, with the TS coming, I will be putting on the cockpit cover but will cover the seat with a blue tarp first just to be sure problem does not re-occur.
 
Thanks Pirate Lady and Stingrayaxe Good suggestion ,I'LL see if they have that soap around here and FWIW all info is good info .. Thanks... now got to go wash some canvas when it stops raining
 
A quality canvas cleaner, let it dry and then 303. I apply mine with a roller w/ext handle and paint tray.
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