A Potential LOW VOC UV Bathtub Refinishing Solution?
In early 2009, UV coatings for bathtub refinishing were introduced to the market by Midwest Chemicals in Orlando Florida, and as such, have been under the watchful eye of many.
At first, Midwest Chemicals limited the distribution of this coating system to loyal customers but have since opened up the availability to all who wish to use their product and offer free training to those who want it.

Curing Kinloch UV Clear Coat
These actions have prompted me to dig deeper and has given me a greater understanding to this process, and, in the midst of this venture, I have been able to test several different methods including Midwest’s system. The Midwest UV product line is not for the novice refinisher and will take practice to master. It is not the type of system that a solo refinisher can rush. In the beginning, you will be satisfied to get one done in a day and should be sold as such. Can the market bear a price increase to satisfy a refinishers living with one tub a day? this will remain to be seen.
With that being said, it only makes sense to figure out a way to expedite the process to enable a refinisher to do a little more. Early in the game, the BRAOA had been discussing the possibility of using a conventional epoxy primer system with a UV clear coat technology to eliminate the possibility of cure through issues using a tinted UV base coat.

Test On Sheet Glass Using Cardinals Wipe-On Silane and Acrylic Urethane
Since this discussion, I have had the opportunity to test this theory. My test results yielded excellent adhesion on both etched/silane and unetched/silane surface with poor results on no etch/no silane surface. This leads me to believe that the magic is in the silane technology. There are a couple of drawbacks with using the epoxy primer… 1.) yellowing will eventually occur, even if you introduce a UV blocker into the scenario, this may only delay the occurrence by weeks. 2.) My testing was done on a pink tub, I chose this as my test subject for coverage purposes and as such required a higher build using Napco’s epoxy primer resin which took in excess of 45 minutes to re-coat using the Kinloch USA UV Stone Cure clear coat. This time frame was in my book way too long even though the clear coat cured quickly.

Tub After Curing
So, in my quest, I stumbled upon Cardinal Industrial Finishes 6S00 series Acrylic Urethane. Bottom line, this coating comes in high hide white, and can be accelerated to dust free in 15 minutes (time enough to clean your gun and set up for clear coat) and is LOW VOC (1.0 lbs/gal). You will get great performance at 1-3 mils thick and as my post in the forum said, the adhesion was incredible using Cardinal’s 2 part silane. Also, you will eliminate any possibility of yellowing from using an epoxy whether water based or solvent based.
Using Kinloch’s Stone Cure had a slight odor but NO VOC. The clear coat can be reduced as much as 50% if needed so it is very user friendly and can be shot from any gun. You will get top performance from this UV clear coat at no more than 2-3 mils thick. Cure out was very quick and yielded a gloss that would make your eyes squint!
With that being said, could this be a potential LOW VOC combination worthy of a professional refinisher? or maybe just a thought to chew on.
If you have any questions about UV coatings as it applies to bathtub refinishing, click here to log into our forum, or, you can contact the BATHTUB REFINISHING ASSOCIATION OF AMERICA.
