Flex-cement

[Bugsy]

What did I do wrong?

Nothing necessarily. The plastic whatchamacallit for the bodkin may have prevented the lid from seating properly. Perhaps removing it will allow for a better seal.

Can I fix it?

Thin with toluene.

How do I stop it from happening again?

I've found Flexament does thicken more quickly than other "cements" I've tried. Buy a tube of Goop the next time you're getting low on Flexament. Thin the Goop with toluene to get your homemade Coltranem's Flexament. For the price of a couple bottles of Dave's Flexament, you can buy Goop and toluene and have the equivalent of many bottles of Flexament. Plus you'll have the means to mix it to the desired consistency and maintain it that way, too.