How long does it take mod podge to dry?

you probably used too thick layers of mod podge. better to use thin layers

Terri, if you have applied a thin coat of Mod Podge it shouldn't have taken more than an hour, however you did say you applied a heavy coat (well, two heavy coats; one after the first "felt perfectly dry to the touch"). The thing is that although it felt dry to the touch on top, being a heavy coat, what you felt was most likely the dry film on top, but it was still damp underneath. The trick is to use thin coats, letting it dry completely in between each application, AND each application will take a bit longer than the one before because the top application will slightly dampen the ones underneath. I am so sorry to hear about what happened. It is very disheartening to plan something and try to execute it, only to have unexpected roadblocks pop up like this. I am posting a weblink below where there are some helpful tips about using Mod Podge, and I hope the website can bring you some answers and more help and success with this and future projects. Have a wonderful summer, and thank you for coming to Hometalk for some answers. I do hope this site is helpful to you.

STAY CRAFTY! :)

Allow one layer of mod podge to dry before adding another. Sounds like that might be the problem, too thick.