Our process is patented and warrantied for five years. However, with proper care, the finish can last for decades. The process we use was developed almost 40 years ago and it involves stripping and acid etching the sink to open the pores of porcelain. We then use 1 coat of epoxy primer followed by 3 coats of a modified acrylic urethane. The process, prep work and layered coatings create a hard surface that is trusted by some of the largest hotel chains in the world, including Holiday Inn and Hilton. If you want your finish to last, the most important thing is how you clean it. Harsh chemicals like bleach or abrasive cleaners like comet will eventually ruin the finish of all porcelain sinks (including those refinished). Bleach and comet remove the protective glaze, which is how stains form on a tub.