Today's tip is another Facebook find. Many thanks to Charlotte Donahue for allowing me to repost it here!
Charlotte writes: I have found that epoxy stays fresher and more pliable when there is some humidity in the container. So, I laid a piece of plastic on top of the epoxy, and then placed a moistened piece of sponge on top of the plastic. Close the tub lid tightly and the epoxy has stayed nicely workable for over two years. Just moisten the sponge a bit every now and then.Thanks again, Charlotte and happy Fourth of July everyone!