Certain situations call for the “big guns”. High Performance Coatings. Occasionally the need is residential but for the most part the application is in a commercial or industrial environment.
For the past several months we have been on a commercial remodeling project and as part of that a steel canopy was erected at the front of the building. Uncoated steel in an exterior environment needs the good stuff !
We submitted specifications for a 2 component epoxy primer followed by a 2 component aliphatic polyurethane. This is the most bang for the buck. Difficult to work with but performs very well.
The steel was dirty but fortunately there was no mill oil to deal with. Mill oil is a lubricant used in the manufacturing process. It has to be removed, usually with a solvent, prior to painting.
Since both the primer and top coat are 2 component you have to keep your eye on several factors. Induction time, pot life, temperature, etc. We had a one hour window to use the primer and get it out of the pump before it set up and a two hour window for the top coat. You do not want this stuff setting up while in your sprayer. We always factor in new hoses and filters and toss them after the job is complete. No matter how much you flush your pump it always seems like there is enough residual material in the hose that when you try to use it again it is like squirting out tooth paste before it gets plugged up.
This canopy got one coat primer and two coats of finish. You want to always check weather conditions before spraying and have a good idea about the next days weather because there are recoat windows you must stay within. For example at 68 degrees you must wait 8 hours to recoat but can’t go longer then 4 days and at 86 degrees you must wait 4 hours but can’t go longer then 12 hours to do a second coat!!
High performance coatings are often difficult to work with but worth the trouble in performance.