Actually modern technology has improved over the past 20 years for do it yourself bathtub refinishing products. A company out of Medford Oregon offers products that are low VOC, offer a 10 year life and come with professional bonding agents so the coatings will not peel like store bought kits.
The coatings require not catalyst are self leveling and are more durable then dangerous urethane coatings. Durable enough for ceramic floor tile application in a commercial setting such as a hotel or store. Drying time is 24 hours for a fast turn around time. Fumes are not a problem either since they are no more hazardous then oil based paints. They are Hi-Bred One Part Epoxy Coatings developed for the do-it-yourself bathtub refinishing market.
This company has sold over 55, 000 units throughout the US and has been manufacturing a range of diy products since 1998. Here is the website address if you want to research their products further. http://www.refinishingonline.com