I have a dimesize chip in my clearcoat on my tank. What is the best thing to use? Clear nailpolish?

 

No, that would look terrible and be highly noticeable. The perfect repair IMO would be to re-clear coat the tank. Second best option IMO would be to have a spot repair blend done with blending solvent. FWIW, I paint for a living and have successfully done thousands of such repairs over the past 25 years.

Good luck with the repair.

 

Do you have insurance? That would over a proper paint job. Assuming you didn't agree to a $1000 comprehensive deductible to save "a few bucks" every month.