> I started building my Coho in my unheated garage in Minnesota last
> November and am almost done.

I also started building a CLC Northbay in November in Central New York. I'm almost finished as well.

>I built an 18' long workbench to build the
> boat on. 48" above the workbench I made an insulated "top"
> with 4 heat lamps underneath. I would work on the boat, epoxy some seams,
> saturate, etc. then screw on rigid pink foam insualtion between the
> workbench and the "top". Even with below zero temps outside, my
> boat stayed between 60-70 degrees.

I didn't go to the extreme of building an insulated box but I used several heat lamps that I could clamp to some stands I made out of 2x2 nailed to a square piece of plywood. I could move them around the shop easily and direct the heat where necessary. The only time I really had to postpone things was when I was ready to epoxy the hull. We got a real cold spell (several days below zero) and I didn't have enough lamps to keep a large area warm enough.

> System 3 epoxy with normal hardener
> would normally cure overnight.

I found that the epoxy would normally cure enough to continue work but I wouldn't say that it cured. When gluing any parts together that require a lot of clamping to pull them together it's just safer to wait an extra day or two before continuing. The other option is to get some cold cure epoxy for some of the epoxy gluing.