This is a great question. There are many factors involved in extending the life of a reglazed bathtub and they are the following: 1) Who did the work? You or a professional. 2) What paints or chemicals were used and their quality? 3) How were they applied? 4) How was the tub maintained?
This question has to be answered in multiple steps. 1) Who did the work? If this is a DIY (do it yourself) job with a store bought kit, you will be lucky if you get a year. With a professional reglazer, you’re likely to get 5-10 years or more before needing to redo the job again. 2) What paints or chemicals were used and their quality? If this is a DIY job, did you use a $30 kit or did you invest in a proper system that includes primer and topcoat paints, cleaning solutions, rust retardants, a chip repair kit and a high quality sprayer? 3) Hopefully you hired a professional reglazer using high quality paints and chemicals and a high quality sprayer. If you did, you should be able to get many years out of the tub before needing to redo the job again. 4) However, the #1 factor in extending the life of your reglazed bathtub is how you take care of it. Never use bleach, steal wool or any abrasives on a reglazed tub. These will damage a refinished tub. When cleaning, use nonabrasive, bleach-free kitchen cleaners instead. Bathtub mats with suction cups will rip off the coating, so don’t use them. Instead, get a no-slip surface applied with the reglazing. Lastly, some people have found that using a urethane polish about every six months has extended the life of their bathtub reglazing.
This information was based on previous blog posts from Dr. Tubs Reglazing* and an article from SFGate written by Renee Miller.
*Dr. Tubs Reglazing is a professional bathtub refinishing company in Toronto, Ontario, Canada. They have been refinishing bathtubs, sinks and tub-surround tiles for over 5 years and have thousands of very satisfied customers in and around the Greater Toronto Area.