Several things will work:

Epoxy thinned with alcohol (works very well and is really messy to apply)

Finish cure epoxy which is thin to begin with is another good option.

Both of the above will flow better if heat is applied with a heat gun. It also shortens the cure time.

Polyurethane paint and Rustoleum paint are two other options. Easier to apply and do the job really well. These paints dry in 24 hours or so but don't cure (reach maximum hardness) for up to a week or more. Alcohol and/or nitromethane will melt them quickly if not allowed to cure properly before use.

EXCAP232