Waterproofing

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Jack Balkenende

Veteran Member
Joined
Apr 7, 2022
Messages
27
Vessel Name
Barbara Ann
Vessel Make
1981 Northern CHB
I saw thing on YouTube using 100% silicone and mineral spirits mixing it together to do your canvas so I ask that's anybody done this what are the feelings on this at least you could use some help thanks Jack
 
Sounds nuts to me and if it doesn't work your canvas is toast. I have had GREAT success with 303 Fabric Guard on a leaky bimini. After washing and treating the canvas it remained leak free for years.
 
+1 303 fabric guard.
 
Sounds nuts to me and if it doesn't work your canvas is toast. I have had GREAT success with 303 Fabric Guard on a leaky bimini. After washing and treating the canvas it remained leak free for years.

Agree 100%. But our new canvas is Stamoid. It is completely waterproof.
 
How do I know what kind of material my canvas is
 
Well, if you don’t know what type of canvas it is, how would you know how to treat it? If it is Sunbrella then 303 is the way to go.
 
I saw thing on YouTube using 100% silicone and mineral spirits mixing it together to do your canvas so I ask that's anybody done this what are the feelings on this at least you could use some help thanks Jack

I used it for 20 of 22 years on our 1990 Regal's Canvas. It was a cotton/polyester duck in pearl gray- can not recall the trade name of the fabric.
1 quart mineral spirits and 1 10 oz tube silicone caulk. Worked just like Star Brite water proofer and smelled about the same too. I still have that 32 year old canvas in my shop.
It worked on my leather work boots too.

In my boat shop, I've used most all common solvents and various caulks, and gotten them all on my clothes. No fabric has disintegrated or had the threads fall out yet!
 
If you have Sunbrella, use 303. But don’t spray it. Take the canvas down , put it on a flat surface and use a small roller. Uses way more 303, but the resultant waterproofing is worth it.
 
If it disolves silicon it'd be interesting to see how it goes as a diy propspeed
 
I've done a number of boat "canvas" projects for myself and others. Ive used 303 Fabric Guard a lot and like / recommend it to others. It is the recommended treatment by the maker of Sunbrella, an acrylic fabric. I will never understand why anyone would spend the $ for a quality boat canvas project and not follow the mfg recommendations for care.
From the 303 mfg site...
"303[emoji2400] Fabric Guard[emoji769] is designed to be safe for use on all natural and synthetic textiles and blends. It should be safe for solution dyed acrylic, polyester, nylon, cotton, wool, silk, and fine leathers like suede.

Do not use 303[emoji2400] Fabric Guard[emoji769] on vinyl, clear vinyl, plastics, rubber, fiberglass, or imitation suede. Consider*303[emoji2400] Aerospace Protectant[emoji769]*instead to protect and beautify these materials."

I have talked to a 303 tech rep re best practices as I was not getting the results I expected and he provided the following recommendations...
Thotoughly clean & dry before treatment
Apply to suspended material (not layer out on a surface like picnic table, etc)
Spray apply, multi coats in a criss-cross pattern to get complete / uniform coverage.
Avoid soaking the fabric, multi light coats are better
Best to Apply in full sun on a HOT day... hotter the better (I was always doing my canvas in spring when it was cool and doing it my garage out of the sun)
Let the 303 set in the sun to warm... do not bring it up from basemen ot out of a cool storage location and apply
Using the above I had noticably better results / performance.

My guide is if it's a woven fabric I'd use 303 Fabric Guard per above.
If interested in whether it is synthetic or natural yarn used try heating / lighter flame or soldering iron on an inconspicuous piece of excess hem material edge. If synthetic it will melt, if natural it will char but not melt. With 303 FG it doesn't really matter as it works for both.

Lastly... Sunbrella (& many others) do not recommend using silicone products as they leave a oily surface that attracts and holds dirt and is very difficult to remove. Dirt is the enemy of fabrics and will cause unnecessary wear and premature failure.
 
The most common (woven) fabric used for marine applications is acrylic with polyester a distant second. There are a few acrylic / polyester blends / coated variations as well. Many boat mfg and custom canvas shops will sew in a Sunvrella tag to confirm genuine Sunbrella was utilized.
If your fabric is not a coated product (smooth solid surface on exterior side) it really doesn't matter as 303 Fabric Guard will work very well.
Starbrite treatment would be my second choice.
If a coated fabric, like Stamoid (vinyl coated polyester) clean as you could any vinyl and use a vinyl Protectant, if desired. 303 Aerospce Protectant is an excellent choice providing some UV protection.
Do not confuse the 303 products as they are very different and can actually be detrimental if used improperly. Best to protect clear vinyl windows when applying Fabric Guard or at min, immediately wipe off any over- spray. Same with 303 Protectant, best to avoid over-spray on fabric.
 
First of all I didn't spend a bunch of money.I got lucky and got a 1981 Northern CHB 35' for 5000$ and I have never had a large boat before.Thats one reason that I joined this forum.And you guys have never let me down.I am not a rich dude.So every penny counts.I'm disabled and on a very tight bugget.am extremely luck to have everything paid off before I couldn't work anymore.
I am amazed at the info I have seen on here and thank everyone who has ever put things on here.Without all of you I'd be way more lost than I am.and I was a shipwright for the last 7 yrs.of work.thanks jack
 
If you are on a strict budget, my suggestion is to take any canvas that does not have a window in it and wash in Woolite at a laundromat in cold water Then use t he Starbrite fabric waterproofer, not as expensive as 303 and just about as good. Shop for the Starbrite, you should find it ar around $50/gallon which should last for several applications using a spray bottle
 
If you are on a strict budget, my suggestion is to take any canvas that does not have a window in it and wash in Woolite at a laundromat in cold water Then use t he Starbrite fabric waterproofer, not as expensive as 303 and just about as good. Shop for the Starbrite, you should find it ar around $50/gallon which should last for several applications using a spray bottle
Woolite or Ivory are good choices. Usually just soaking will work ( ive done many canvas pieces in the bathtub) and if really stained you can use a mild bleach solution with acrylic without issue.
Best to rinse 2 - 3 X. I usually take it outside in a garbage bag, hang on line snd hose down bith sides a few times.
 
Well I ordered a gallon of mineral spirits and 10 tubes of 100% silicone.so we will see how it turns out. I brought the bimini top home and had to clean it up.boat Sat for like 5 years from what I understand didn't seem to have much maintenance done batteries were half empty.the whole boat has a green hue to it, and that's the part I can tell was pressure washed recently But bimine top had mold on it a lot of pressure washing and spraying washing now it's clean and ready to treat I'm going to do it first and see how it turns out but I have all the canvases for the boat. And I'm not sure what kind of material it is it looks like a cotton type fabric to me. But I could be wrong. I should run down to the boat and get one of the smaller ones to do first in case something goes wrong with this. Well wish me luck I'll let you know how it goes. Catch ya later, Jack
 
Just curious what a gal of thinner and 10 tubes of sillycone cost you?
Standing by to hear how it goes... and importantly how it fairs over coming years???
Have you gotten an estimate or a guess on what replacement would cost if things don't go well?
Good decision making evaluates plusses and minuses. How much is the potential savings vs the potential cost. Especially w/ a utube hack as a solution.
I'd be interested in some pics of how the mixing process goes as well as the application.
 
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I buy 303 fabric guard by the gallon and use it everywhere. Not just on boat canvas, but also clothing and patio umbrellas or anything that you want UV protection and waterproofing. Best stuff around. They also now make a clear vinyl protectant that I use on the windows and is much easier to use than anything else like Imar.
 
I buy 303 fabric guard by the gallon and use it everywhere. Not just on boat canvas, but also clothing and patio umbrellas or anything that you want UV protection and waterproofing. Best stuff around. They also now make a clear vinyl protectant that I use on the windows and is much easier to use than anything else like Imar.

I am not in love with Imar products but Strataglass requires it for warranty coverage. So I use it on my new enclosure. For eisenglass I really like Sumner 210, it is really easy to use and works great.
 
I am not in love with Imar products but Strataglass requires it for warranty coverage. So I use it on my new enclosure. For eisenglass I really like Sumner 210, it is really easy to use and works great.

Thanks Dave. Have you tried the 303 product? I was using Imar for years because I was convinced that it was the best, but it's a fair amount of work. The 303 product is spray on and wipe off. Water beads up on the plastic and because it's so easy to use, I do it a lot more often than I did with Imar. It's my new go-to for eisenglass.
 
Thanks Dave. Have you tried the 303 product? I was using Imar for years because I was convinced that it was the best, but it's a fair amount of work. The 303 product is spray on and wipe off. Water beads up on the plastic and because it's so easy to use, I do it a lot more often than I did with Imar. It's my new go-to for eisenglass.

No I haven’t because I have used the 210 for years and loved it. It was so easy to use and water beads up and runs off very well. But I just spent a small fortune for new canvas with Strataglass and I don’t want to void the warranty. And the fabricator specifically said he wanted me to use Imar stuff. He is the best fabricator in our area and he does know his stuff, so I guess I should listen to him.
 
No I haven’t because I have used the 210 for years and loved it. It was so easy to use and water beads up and runs off very well. But I just spent a small fortune for new canvas with Strataglass and I don’t want to void the warranty. And the fabricator specifically said he wanted me to use Imar stuff. He is the best fabricator in our area and he does know his stuff, so I guess I should listen to him.

No worries. Just curious what kind of warranty you have. Also, could using a different product void the warranty and how would it be proven? Example, a new car may have a 10 year warranty against body rot, but there is no requirement for washing and waxing and even if there was, how would it be enforced?
 
It isn’t a great warranty but it covers 2 years with replacement Strataglass but not the labor to fabricate new panels. Not great but slightly better than nothing…
 
naptha and silicone waterproofing

The boat cover for my 16' runabout was getting tired its a ten year old cabelas trail master cover and I too saw some youtube vids calling for mineral spirits and silicone, then I saw another using naptha and silicone thought I'd give it a try, what the heck 2 tubes 100% silicone 1 gallon naptha about $40.00 all told, I used an old weed sprayer that I threw away afterwards next time I think I would use one of those small rollers. Worked very well!!

 
Since you're interested I think I will take the time to maybe record mixing it up and stuff I'm going to go down to the boat and grab one of my smaller canvases that way if it does screw up I doesn't cost me an arm and a leg to replace it but they're all in good shape they're just not waterproof anymore they look new to me. Jack
 
Just wondering why'd you go with a Napatha instead of the mineral spirits
 
why naptha?

so I actually tried it with mineral spirits but I screwed it up. I don't really like mineral spirits for paint clean up and such. I had acquired a gallon of oderless sunnyside mineral spirits and there was another quart of kleen strip "GREEN" and I thought what the heck I'll use this stuff and get rid of it, so the sunnyside poured in clear and the quart of kleen strip poured in milky, a little warning flashed in my head but I ignored it as I was preped and rolling so I mixed on, FAIL It made jelly almost a gallon and a half of jelly. After a week in the sun it flopped out of the bucket to be more than a cubic foot of silicone foam/jello . Mineral spirits probably works, I watched those videos too, just make sure it's the real thing (clear)
and I was pissed so when I saw the other option I went with it, It worked very well I'm quite impressed, the cover feels sturdier, I'll bet it will go another 5 years easy
 
Just wondering if you look at the ingredients in the products mentioned what are the ingredients.
 
For years I bought products for waterproofing my clothes and such it was a silicone based product,still used by many today for shoes,hats ect.
Finally received the silicone and mineral spirits today.ran to the boat and grabbed all the canvases.
Going to wash all then will pick the smallest one to do my test run on.
There are so many different canvases and I have no idea where hardly any of them go. It's is going to be interesting to figure it all out. In fact I have one great big huge large very unusually shaped canvas that I have no clue where it would go My best bet is either a cover for the dinghy or else it's supposed to cover the whole flying bridge but I kind of doubt that. I've tried getting a hold of the previous owner but not much luck there yet. So this ought to be interesting I'll keep you informed, Jack
 
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