Long time drying

[Jim]

Seeking advice: Anyone have advice on what to do when paint or clearcoat won't dry completely?
I've recently completed building a new model, but can't finish the job because the paint doesn't seem to want to dry completely. Not all of it, mind you. Just a few spots on ghe wings and fuselage. To explain:

My usual practice is to paint the model with acrylics, then after drying, give it a coat of clear enamel (Floquil Railroad Colors Crystal Clear-Cote) to provide a smooth, shiny surface that the decals can best adhere to. Sometimes, if it's particularly humid or cold in the workshop, this may take a day or more to dry completely. Then, after attaching the decals and letting them set, I like to give everything a final coat of Crystal-Cote to seal the decals and make everything look sharp visually.

But this time, for some strange reason, the primary layer of clear-coat won't seem to dry completely. It remains tacky in spots a good two weeks after application. I set is aside in a climate-stable space, but the tackiness persists. I'm concerned that applying decals and another coat of crystal will result in disaster. I've thought about hitting it with a heat gun or hair dryer, but the idea of what might happen gives me the fantods!

Anybody have any ideas or suggestions what to do?