waterproofing

[tonyg]

this is my first post as a newbie apart from a salutation and intro. My mate is a retired boatbuilder and altho at the end of the line healthwise he owns and still operates his 40' timber cruiser. His decks and shower room on his boat are lined with calico ( a type of thin canvas) and sealed with "boncrete". I don't know if you have the same stuff there (brandname) but I'm sure you have something similar. It is a concrete waterproofing additive which can also be used as a carpenters glue and thinned down as a primer under acrylic paints. He has been using it for 40 years and has had no problems. It seems that a tear covered with calico and glue sealed with say 6 coats of thinned boncrete would be a good basis for an acrylic house painted finish. Much easier than fibreglass and stuff-all fumes. I believe epoxy is great for boat building but is overkill for a TD apart from gluing. Expensive epoxy cannot replace proper engineering. jmho

[GPW]

Great tip Tony !!!! Thanks !!!

[Cliffmeister2000]

I would be curious about how much it weighs?

http://www.bondall.com/_webapp_5362/BONDCRETE

[Cliffmeister2000]

From the Bondall site:

For waterproofing applications for wet areas, please refer to Bondall Hydrocrete, Bondall Silasec, Bondall Aquatite, Bondall Pondtite, Bondall
Terratite and other Bondall waterproofing products.

Do not attempt to apply oil-based paints over BondCrete.

[Cliffmeister2000]

I have not been able to find any sources in the United States for this product.

[tonyg]

Cliff, calico material is quite light, about the thickness of a painters drop sheet or a summer shirt. None the less it is quite strong, being a sort of thin canvas. when the bondcrete dries, its only the weight of a thick coat of paint plus the material: say about a pound or so to the square yard. (I was educated in feet and inches and live in a metric world... gotta do a lot of mental conversions)
Tony

[angib]

A traditional way of waterproofing boat cabin tops (made from individual planks) was to glue medium/heavy canvas to the wood and then paint it. I suspect the waterproof glue and Bondcrete are both just a PVA or woodworkers glue.

Andrew

[tonyg]

I'm sure that you are correct...

[H-Balm]

Sounds cool.

So who volunteers to go do it first.... for educational purposes?

[Postal_Dave]

I just did an experiment and I'm going to repeat this post on another thread. I'll add pictures soon.
I took 2 cardboard boxes and basically painted the inside of them with Titebond II. In Box A, I then took a piece of Jersey type fabric and lined the inside of that box with that and then coated it with some more Titebond II. Box B, I didn't line.
It took several days for the Titebond II to dry, the fabric in Box A took almost 4 days.
I ended up giving both boxes a week for the Titebond II to dry and then I Primed them with Zinser 123, oil based primer. It usually takes that primer 2 hours to dry, but on top of that glue, it took another 3 days. I ended up giving that 4 days total before painting.
I painted the inside of the boxes then with Kilz Casual Colors Interior/Exterior Latex white paint. It took 2 days to completely dry. The lined box, Box A, got only 1 coat of paint but Box B got two coats of paint.
Sunday evening I placed both boxes outside and put 1 gallon of water in each. As of Wednesday morning, except for some evaporation, both boxes are still holding the water without problems or leaks.

The Titebond II sealed the openings in the Box B and is holding the paint. I think the glue would hold the paint a little better if I would have sanded the glue a little after it dried. In Box A, the Titebond II made the fabric rigid and water tight.
I'll put a couple of picture in my profile of the boxes shortly.

[NathanL]

I'm sure there are a milion variations but this is one I've seen used multiple times in decks over a cabin area in wooden boats.

Put down a medium/heavy coat of Titebond II and put the canvas down over it and leave it overnight to dry.

The next day iron the canvas and spray it with light mist of water to shrink it up and get it tight. Put a coat of thinned Titebond II onto the canvas and get it into the canvas good but can still see the weave.

Then paint it.