Double-check my epoxy/fiberglass plan

[Kharn]

So I'm building a 5x10' weekender, and I want to make absolutely sure the seams are waterproof.
I'm using MDO plywood, so the faces do not need to be treated, just the joints/seams.

The side profile is ~31', plus ~30' of side-to-side seams, ~4' for the roof vent and ~8' for the air conditioner's hole, so a total of ~104'. I'm planning to use wood screws from the outside into the stick frame to hold the roof panels onto the walls, so 6" wide tape will give me 2" margins for screwing on each side of the joints. Smith's Fill-it will be used to fill any gaps and the counter-sunk screw holes. Afterwards, the entire tear will be covered in two coats of 100% acrylic latex primer, and two coats of 100% acrylic latex exterior paint.

So far, my shopping list is:
1 gallon West 105B epoxy
1 quart West 205B fast hardener
1 pack West 300 Mini-pumps
1 50yd roll of West 733 6" tape, 9oz
2 pints Smiths Fill-it

I know fiberglass won't fold 90 degrees easily, but what round-over do I need? Is a 3/16" or 1/4" radius sufficient between the roof and side wall?
How are my epoxy or fill-it quantities? From West's guide, a 1 gallon kit should be sufficient to fill and coat 50 yards of tape 3 times, but is that a sane amount of epoxy for a teardrop?

[rowerwet]

I use 1/4" round over for all the joints that get fiberglass tape on them, no issues one many boats.
as for quantity of epoxy, how easy is it for you to get more in a hurry? I have one store nearby that carries it so I can cut my quantities tight (the price is lousy at the store though) if you need to wait for shipping, getting extra will cost less in shipping in the long run. you can always use it somewhere else.

[Kharn]

I work near a West Marine, but the price would be lousy.

[les45]

I used the Aeromarine 1.5 gal kit on my 5X10 weekender and I had about half of it left over. My total numbers were about the same as yours. I used 4" fiberglass tape on all joints and rounded my 90 degree corners to about a 1/4" radius. I probably added two to three coats over the tape after the bedding coat as I feathered the edges and covered the texture of the tape. I was careful in sanding the corners, but I ended up covering all my 90 degree corners with aluminum edge molding with the black vinyl insert. I used Zinsser oil based primer and Rustoleum for my paint system. I did a lot of homework on the primer and found that Zinsser was the best combination to stick to epoxy and to hold the oil based Rustoleum. It's been on for nearly two years now with no problems although it is garage kept.

You can see some of the details of my epoxy work here: viewtopic.php?f=50&t=49333&hilit=les45&start=60