@rottrunner I sometimes make Native American Style Flutes (NAF).  I've tried a number of different  finishes on them and the only difference that I can detect is drying time.  Clearly, the solvents evaporate more quickly in warm and dry conditions than they do when it's cold and wet.  When you are waiting for a finish to cure, you're just waiting for the evaporative process to complete (oils like tung oil take a very long time regardless) and so the same rules that apply to the evaporation of water apply to the evaporation of other solvents such as alcohol or turpentine, although the drying times are different.    

After dealing with a number of different finishes, I've found that for my purposes shellac is one of the best.  Of course, since a native american flute is something that people put in their mouths, having it finished with a non-poisonous substance is very important to me -- you won't have that issue with a fiddle so you'll have more options.  

My experience has been that when you think it's dry enough to touch, give it another day or two before you do.  When you think it's dry enough to apply another coat, give it another day or two. Don't be in a hurry when applying the finish. 

@augustoad thanks for the link, that was a really good article and it contained a good link for obtaining pigments.