Glue/canvas/paint.

[dales133]

Sorry to be asking loads of questions but it seems to be the sensible thing to do.
This question has several parts.

Firstly before I learned of "the mix" I paid way to much for an acrylic timber sealer that does the same job in 2 or 3 coats.
I tested it and wet some ply and timber off cuts with 2 coats and the water just beads .
I'm going to coat it with 1 coat of poly aswell on the skins.
So with that said is it feasible I can glue canvas directly over those skins with sika wood glue (pretty much the same as titebond but cheaper here) and paint without using resin on the joins?
I'm looking at painted sides and aluminium sheet roof/front/hatch and don't want viable canvas seems at the wall tops how best to join so the seems on the root?
I'm sort or thinking out loud as much as asking for ideas but I want to build it to last so help or ideas very much apreciated

[KCStudly]

I prefer to get the full strength bond between raw wood and glue. TB2 is highly water resistant (TB3 is water proof).

If you want to seal first make sure that you rough up the surfaces where you want glue to hold; a couple of passes with 100 grit paper should do the trick.

For the canvas to aluminum transition, I would do the side walls first, wrapping over the top a couple of inches, at least past the width of the trim you plan to use. I would try to minimize the number of pleats/darts and v-notches so that the folded edge of the canvas lays down as flat as possible. The rest should be pretty straightforward using sealant at the edges of the AL skin, under the trim, and in the screw holes.

If you are doing a plywood roof skin under the aluminum, I don't see any reason to canvas that. Just seal with the mix, and rough up the edges where the canvas will wrap.

[KCStudly]

Should add that I would prime and paint the canvas before putting the aluminum on. You want that to be fully sealed so that water can't wick under the AL.

[dales133]

Thanks bud yes I intended to do that.
Perfectly open to suggestions. ..if you think my waterproofness won't suffer gluing to bare wood then that's cool.id thought about canvassing the roof aswell purely as another waterproofing measure

So no fiberglass needed in your opinion then KC

[KCStudly]

I don't think you can ever pay too much attention to water proofing, but at some point it might be overdoing it with different materials piled on top of each other.

I didn't realize that you intend to glass anything. Are you putting tape on just the corners, or glass weave the whole thing? I wouldn't bother with the canvas if you are glassing the whole thing. In fact, I wouldn't bother with AL if you are glassing the whole thing. If you are just glassing the corner joint with FG tape, then I stand by my original recommendation; just be sure to scuff the epoxy up so that the glue will grab.

Maybe I'm confused about what your plans are. I thought you were doing canvas over ply on the side walls and AL over ply on the front/roof/hatch.

[dales133]

Yea sorry mate if I wasn't clear, I was saying if I use glue canvas paint do you recon I should glass the wall to roof joint.
I didn't intend on glassing it all

[KCStudly]

The only possible conflict I can see is the fact that the glass tape and canvas both want to have a bit of a radius to wrap over so the stiffness in the fabric doesn't cause it to lift at the edge before the glue/epoxy sets up (bend radius issue). Some AL trim has a smaller lip on one side and might not cover the needed radius; so something to test or work through, maybe.

I like the idea of sealing and reinforcing the corners with the glass, but depending on your build method and how the corner joint is assembled, it might be redundant to the canvas and glue. Say, for example, you use the Fredrick's method (ceiling and roof spars tied into ledge at top of wall, spars infilled with profile blocking before attaching roof skin). There is a lot of structural integrity there already, so now it's just an issue of sealing. While the glass will really stabilize the edge right at the joint, you might have some tedious sanding to do to keep the edges of the glass tape from telegraphing thru the canvas, maybe.

Of course this all conjecture on my part. My build is very different from traditional.