In response to "Joan at Home" I am a professional refinisher in my area and if your tub has yellowed over time it was coated with an epoxy paint. (Acrylic or not) Atenic light rays (ex. sun, fluorescent lights) destroy epoxies color lightfastness over time resulting in loss of gloss, chaulking, yellowing etc. However, there are excellent commercial coatings for this application that do not yellow, retain there high gloss and if the substrate is properly prepared; do not peel. Hope this helps. Carl P