this was the stage where they added too much weight to their kayak by adding too much epoxy

I built a pair of Arctic Terns a few years ago. On the first one I took advice from a How To book a little too literally. My first fiberglassing experience was the inside hull. The book said "you must begin to squeegee about 30 minutes after the epoxy has been applied". To me that was pretty clear. I noted the time I started, added 30 minutes to that and began to squeegee the excess epoxy off. The photo below shows what the finished product looks like. (This is not just what it looked like the day I did it. This is what it looks like today.) My work area was only 63F - not what I'd consider warm. I was using the System Three epoxy with medium hardener. Apparently the epoxy kicked off in less than 30 minutes and I could not remove the excess. With the inside deck and the outsides of that Tern and with the entire next Tern I did a seal coat late in the day, so temperatures were dropping, then glassed the next day. I made sure the glass was fully wetted, then began to squeegee the excess. No more waiting for the clock. No more problems.