I applied a filter for the first time using oil paints and turpenoid. It's been about 24 hours and parts of the model are still tacky. How long should I wait before applying an acrylic flat coat ?

"BTD", did you use turpenoid or turpenoid natural? If your answer is the second choice then I hate to tell you this but it won't ever dry. I made the mistake of using some on a kit about 3 years back and it's still tacky to this day . If you used regular turpenoid then give it a another day or so at least. If you are experiencing some high humidity where you live that is one thing that could cause it to take longer to dry.

Mike

Thanks. Yes it has been humid here as of late, so that may be it.

And I did not make the mistake of using Turpanoid natural this time :-) I learned my lesson on a model I tried a few months back. Man, what a mess!

i use mineral spirits and don't have any problems with drying time. drys up fast imho

Frank

Try enamel thinner! It smells a lot but works fine!
The only trick is to let paint dry thoroughly and seal it with a clear varnish!