Thank you for your replies. It had cured when I arrived today. I will probably have to wait 2 days between each session from now on.
Rick, I'm using a laminating epoxy I bought from Germany. Don't know much about it. I'm happy that I managed to find the mixing ratio, which wasn't on the labels. But it has worked fine. Covering to get the green house effect was a good tip.
Rob, thanks, I'll try your method if in doubt later. I think this epoxy has 45 minutes open time.
Arttu, thank you. I've seen a video of your boat, sailing on the sea of Åland. Nice boat.
Rob Riley, yes, I should do that, if I'm not able to borrow someones garage to work in.