Are all epoxy resins waterproof?

Even if a packet doesn't say it, is it waterproof?

Other answer:

PsqMy:
no epoxy is 100% waterproof for ever – even the best boatbuilding epoxies will eventually let some water through (may only be 1% over 2- 3 years). but the good ones like West Systems & Botecote etc are close enough to waterproof for for practical purposes. Some not designed for this sort of use may well be a lot worse.
adaviel:
Probably. At least anything you buy in a hardware store isn't going to fall apart in the rain. For underwater use, you should probably read the label.

(I would have just said yes; I started using Araldite decades ago, which is waterproof, but pibe convinced me to look. Durcupan is water-soluble)

?:
but the good ones like West Systems & Botecote etc are close enough to waterproof for for practical purposes.
?:
Definitely not. Check with the manufacturers to find the best one for your need
pibe:
No, they are not.