Sticky resin

A couple of things can go wrong when working with resins. In order to avoid repetition of the mistake and to try to figure out how to fix things, we all pondered what might have happend last Saturday, which made the resin still be sticky after a week.

I will list the possible factors, in what I presume is an ascending probability:

White pigment: I have added white pigment into the resin, in order to save the time and effort for painting the interior white. I used titanium dioxide, like I have before. I never had negative results before. It looks awfull on the wood. But that is another story. A second coat should help fix that.

Mixture: I used a scale for the mixture, and I'm pretty sure I have the proportions right. I have also stirred it all extensively to make sure the catalysator got well into the resin.

Alcohol: I've added alcohol the the epoxi mixture to make the mix more fluid, so it could penetrate better into the wood. I did so after a recommendation of an experienced boatbuilder. The proportion was around 7-8%, like recommended.

Plastic cover: Jonas and I left the boatshed right after applying the epoxi. As I allways do, I've covered the boat under a plastic cover. It is basically to keep cats and dust out of the boat. Valmir, my neighbout boatbuilder, says that lack of ventilation might retard the curing process. He claims that leaving it ventilating will fix the problem. I'm not sure the lack of ventilation is a cause nor whether ventilating now will help. But I did leave the boat uncovered.

Shelf life: The batch of epoxi used was a different batch than the one I've been using before. This batch must be reaching the limits of its shelf life. I was aware that epoxi catalists might go bad when it gets old... Therefore, I've tested the resin on samples before use. They cured nicely. And I did use it on the hull the weekend before, without problems.

Temperature: Not all the applied resin was sticky. Some, maybe most places were cured and dry, allright. To me it seems that the places we applied last were stick, while others not. We worked until fairly late into the day, around 17:3ohs. It was dark when we left. These days it does get fresh and humid at dusk... Epoxi doesn't like that. It wasn't raining though, and temperature was still around 22Deg. C., I guess. But this together with a not so strong catalysator, might be enough to account for the mess.

So, what do I do now? After a week, I'm not sure much can be done to fix the issue. I had a feeling that the heat from the sun helped. I will therefore try to use more of this medicine - heat. I'll buy a heat gun and use that also. I'm aware that time is of the essence. I'll see if I can take one day off, in order not to wait one more week...