What is the best material to apply to a cheap metal fastener on costume jewelry?
I have used clear nail polish for that very sort of thing… and it does work… but it’s messy and not terribly convenient. Plus, it’s easy for the clasp to get so gummed up that it’s unusable. What you want is something that will coat the metal of the clasp without changing it’s appearance or functionality. I have used Krylon clear acrylic spray for a multitude of tasks. Though I haven’t done a necklace clasp, I have done earring backs with good results. You may need to wrap the neclace parts which you don’t want to be coated with saran wrap or some type of masking material before you spray the clasp. Good luck, I hope this works for you.
