Heating Waterborne Finishes
Keeping your finish warm will improve flowability and maintain consistent viscosity — but check with the manufacturer for allowable temperature ranges. February 13, 2006
Question
I'm thinking about adding a recirculating heater system to my Kremlin 20:25 pumps for spraying my waterborne clearcoats. Is anybody else doing this or is it a bad idea for waterborne?
Forum Responses
(Finishing Forum)
From contributor A:
I am curious as to why you want to heat the coating. I've heard people do it for solvent-based to help with flow out. Is that your intention? I use water-based, and maybe it would help me.
From the original questioner:
Ideally for the same benefits that the solvent-borne people get. Consistent viscosity from 6 am startup until 3:30 shut down in order to maximize the solids transfer. I was just wondering if the waterborne would get too snotty or crystallize or something.
From Paul Snyder, forum technical advisor:
Check with the manufacturer of the water-base finish. They can tell you the proper temperature range you can heat their finishes. I've heated pails of WB, but haven't used a recirculating pump. Don't know if there would be any additional concerns related to the pump/recirculation, but the manufacturer should be able to tell you.
From contributor M:
Heaters work great for waterborne materials! You can atomize with less pressure, reduce overspray and maintain consistent viscosity all day long.
From contributor A:
How are you heating? I've heard of people using heating pads in pressure pots, but mostly due to cold air temps, not attempts to improve flow. Though it seems like an easy way to achieve the improved flow and other benefits you mention with less cost and equipment.
From Paul Snyder, forum technical advisor:
You can get an electric heater with a thermostat that fits a 5 gallon pail. If your supplier doesn't stock them, you can find them online. Stay within the finish manufacturer's temp limit!
From contributor M:
The turbine sprayers use a heated hose for water base coatings. The hoses sometimes get too hot and cause problems in the finish, because the coating is drying too fast and without good flowing out. They sell a heat pump that controls the temperatures of the coatings - it has been around for decades. It works well with high solid coatings. Just getting the coatings warm will improve the flow out.
