I'm hoping that someone can shed some light on a problem that I'm having.

I'm currently trying to regelcoat the bottom of my Nacra 6.0 cat. The gelcoat had been completly worn down and the glass was exposed. As I was preping the hulls, I noticed that a previous owner had attempted to solve this problem using some sort of greyish paint. The prep work ended up taking much longer than I expected since I had to sand all of this stuff off.

I sprayed the gelcoat onto the hulls while the boat whas in my garage, and used a couple of electric space heaters to keep the area nice and warm while the gelcoat cured. I used 12 drops of hardener to 1 once of gelcoat, and thinned the mixture a bit using acetone so that it wouldn't clog the sprayer.

Here's my problem, I have an area on each hull, just forward of the daggerboards that never fully cured. It's still takey (sp?) and it's been almost a week since I sprayed it. I'm wondering what went wrong? I have two possible ideas.
1. I didn't get all of the paint off the hull there.
2. This would have been the point farthest away from each heater, so was too cold to cure.

How do I fix this problem?

Thanks in advance for any help, I'm pretty frustrated at this point.