: Yesterday morning I put what I thought was the last of the epoxy on my
: guillemot. It was a skim coat over a small repair where I got a bit
: carried away with sanding. It has now been over 24hrs and is still tacky.
: I am using West system which has always dried faster than this. I plan to
: wait another day or so and see if it is just being very slow.

Tacky is OK as long as the material has started to set up and is not still a liquid with the viscosity of honey.

The epoxy polymerizes faster when it is hot. Some of the heat for this reaction usually comes from the chemical reaction between the resin and the hardener. When the mixed resin is confined in a cup the concentrated heat of the reaction can cause the mixture to gel quickly, but when it is spread out thin it stays cooler, and can take longer to harden.

Assuming you mixed the batch correctly, I suspect you've simply put on a layer which is smaller and thinner than you are used to. Just give it some more time, or maybe some gentle heat. If youor temperature is dropping at night, a 100 watt light bulb about 12 inches away will raise the temperature slightly and speed curing.

If the material is still liquid, then you should be able to lift off the patch with no problem. Most of the resin should come with it, and the rest can be cleaned up with vinegar, or, if you prefer you can use a solvent like acetone-- but vinegar is cheaper and safer. Clean off all the mess and start with a fresh patch.

I put some patches on my canoe earlier this year and used some old resin. It took several days for the tackiness to diminish, but when I came back to the job a week later the patches were on solid and easy to sand smooth. These things happen.

Good luck on this

PGJ