Glue dilution

[Rainier70]

I like the foamy concept and the many great builds you guys have done. I am looking at the possibility of using some of your techniques on my cargo trailer. Weird huh! Unfortunately, I haven't read enough of the foamy threads to find the information I need. I am looking at insulating the underside of my ct with 2 inch pink foam, then protecting the foam with a layer of canvas with Titebond II. What is the best dilution of the TBII to use on the canvas? How many coats? The size of the area is about 6ft by 13ft. How much coverage is a gallon of TBII ??

I am also debating on putting the canvas directly on the foam panels or doing a canvas overall sheet that is below the foam and runs flat across the ribs. I would think that the canvas on the panels would be more protected and maybe stronger, but the flat undercarriage might help on gas mileage.

So far I only know enough to get myself in trouble. My other option is to use frp panels across the bottom.

Thoughts anyone.

[GPW]

R70, that would be entirely possible ... 50-50 mix of glue (TB2) and water works fine ...for canvassing.. gives you twice the coverage , which depends how much apply at a time ... The bottle does not list any specific coverage figures...

[Rainier70]

Thanks a lot for your help.

[Rainier70]

Okay, I could use some more help and details. I have read a ton, but no one really details steps on how best to put the canvas on.
I have preshrunk my canvas, but am not sure on the best way to go about gluing it on. Some say to paint the foam piece with thick undiluted TBII, others say diluted on this step too. Some wet the canvas first. Is that with just water or dilute glue? Some put the canvas on dry. Some paint the glue on the canvas instead of on the foam. Some rough up the foam face, some don't. Is there a norm or a best way???

Thanks!

[twinight]

I just canvased (1) 5x13 side and used 1/2" gallon of glue.
More details in my build thread.
http://www.tnttt.com/viewtopic.php?f=50&t=59146&p=1073068#p1073068

I did read that Gripper primer adheres well over foam and I did notice that the TB2 did not stick to foam as well as the wood.

[GPW]

Cindy ,the whole covering process is not very critical , as each method works (all tested) ... I think you should practice cover a cheap foam cooler or something first , just to become acquainted with the process... Then there will be no surprises later.

[lthomas987]

Cindy ,the whole covering process is not very critical , as each method works (all tested) ... I think you should practice cover a cheap foam cooler or something first , just to become acquainted with the process... Then there will be no surprises later.

Cindy,
I agree with GPW that testing is a great idea. I built and covered a small sample trailer for my bike. You could even just build a small foam box to practice gluing edges and such.

I tried nearly every option on a different part. Lots of diluted glue, wet canvas, dry canvas, full strength glue, lots of full strength glue, wetting the canvas after it went on with a spritz bottle, wetting it before it went on, roughing the surface, not roughing the surface, I tried nearly everything I had ever seen in the big thread.

In the end I learned that you only need to add a TINY bit of water to get TBII to spread a lot easier. Note the guy from the manufacturer's bit about diluting 5% to halve the viscosity (that's 6.4oz just about 3/4 of a cup in the whole gallon). I was using less than a teaspoon in about 8oz to thin it for easier spreading. Wetting the canvas made getting things to stick hard. But is probably a great idea if it is HOT and dry out. So that stage was a pain.

I think the reason there are so many different opinions is we're all working in different conditions. I did all my different gluing indoors in my living room so the conditions were pretty even. 65-68 degrees, 40% humidity if the sensors in the house are to be believed.

In the end in my very moderate conditions I liked using a foam brush (probably a roller when I do the full sized trailer) to put on a thin layer of TBII and then smoothing from top to bottom starting in the center and working towards the edges. Pushing any slack, stretching or bubbles outward as I went. I then used some thinned TBII as a second coat. If my glue was drying too fast to be workable I'd definitely add a bit more water.

I had fewer problems with edges curling and coming up once I committed to roughing the foam up more or bending around the edge or at least taping it over the edges onto the next adjacent side.

[Rainier70]

Thanks very much everybody. Your answers help make things a lot clearer.

When you put the TBII on as a second coat does it soak through the canvas very well, or is it more for stiffening the canvas rather than sticking power?

[GPW]

You don’t need a second coat , just prime and paint over that !!!

[lthomas987]

You don’t need a second coat , just prime and paint over that !!!

Wait?!?!?! I can just glue the fabric to the foam and go straight on to primer? Regular non-Gripper primer? (something like Zinzer 1-2-3 which I have a couple partial gallons of?) Good thing I have another surface I can test on.

[GPW]

Yes, the TB2 is merely to adhere the canvas to the Foam .... any primer (foam compatible) will handle the rest , to “size” the canvas and fill in the weave to some extent ... After that a couple coats of good exterior Latex paint (and some decorations naturally ) , and you’re done ...

[Mary C]

Not to throw a wrench in here but Cindy do I understand you want to use foam on the underside Meaning the bottom, the street side of the Trailer? I 'm not sure you ment that or just the inside of the walls or the top of the floor . I know sometimes I read things to mean something else. Can you clarify my old muddled mind Please?

Mary C.

[Rainier70]

Yes, underside insulation.

[Mary C]

I am not sure that just foam and canvas glued will hold up very well from the road spray. Guys, now is time to chime in. Cindy you will need to have something a little harder than that rocks and other road spray including chemicals will not deteriorate the canvas and glue. You might want to put some wood on the underside not just foam.

Mary C.

[Rainier70]

The foam will be glued, clamped, and screwed to the bottom side of a wood floor between the frame sections. The glue/canvas/paint layer is just a light protective layer for the foam. The canvas etc will be put on the sections of foam before they are installed under the frame. If the canvas layer doesn't hold up to the abuse, I can always enclose with the heavier frp panels.