Is there a product that gives a hard coat to dvds??

like the one blurays have?

been going through my dvd collection and i have about 100 scratched dvds. only light scratches, most of them still play, but im not convinced they will for much longer. ive done a search but can only find blank dvds with a hard coating, not something that will coat dvds ive already got. i dont want one of those dvd repairers that really ruins the disc by scratching the whole disc to make it play