OP827 wrote:How did you prepare your foam before gluing canvas on it? The foam looks untouched at the photo before putting cancavs on the roof..
I've just sanded the sheen off of it with an orbital sanders and about 100 grit sandpaper. I used to try to rough it up more but it appears to be unnecessary as the canvas sticks just as well. That may be because I am immediately coating the canvas with thinned-out tite bond 2 and then squishing it through the canvas to make sure the canvas is really bonded well. If that step is skipped, maybe it wouldn't stick as well.
Here in the desert the TB2 sets up pretty quick. That may not be the case in more humid parts of the country.
I recommend practicing on smaller projects before you get to the outside. I built a desktop (using it right now) as a test of the technology, then I canvased the door and that taught me how to handle curves and seams, then I did the interior of the walls and finally I helped my wife canvas the back of her stage (professional flamenco dancer). All of that has paid off. The only problem I had was that all of my practice was on things that were laying down. When I got to the exterior wall it was standing up so I had to adjust but hanging the canvas beside the wall works well.
Here is the desktop