Thursday, December 4, 2008

Painting Tip for water tanks this time of year (late fall and early spring):

When painting a tank during the cold weather that Mother Nature has been providing us lately 3 things are important:

1: Ambient Temperature
2: Substrate Temperature
3: Temperature of the actual paint, itself

All 3 of these variables need to be considered and monitored closely to determine if conditions are acceptable for successful coating application and performance. But the one variable that often times doesn’t get prioritized enough is number 3—Temperature of the actual paint, itself.

Most of the epoxies we use in the tank industry have a cold-weather (rapid cure) version that is appropriate for late fall and early spring time weather conditions. Often times the minimum ambient and substrate temperature for these cold-weather versions is 35 degrees Fahrenheit. But the issue that is just important, but sometimes doesn’t get the attention it deserves, is the recommended minimum temperature of the paint itself. Most manufacturers’ data sheets state that for optimal application and performance properties, paint material should be a minimum of 60 degrees Fahrenheit. In the real world, a tank field site is where the paint is stored. And if someone doesn’t ask the question of raise the issue, the paint is either stored outside underneath a tarp or inside of a trailer that is not heated.

So if the ambient high temperature for the day is 47 degrees, and it is partly sunny, then it is probably acceptable painting weather. But if the night before, the temperature got down to 27 degrees (and the paint wasn’t stored in a heated area), then the temperature of the paint itself is probably no more than 35 degrees (because the paint inside of a 5 gallon container takes longer to warm up) and that is not good. Often times, the paint is more difficult to work with and as a result and it creates an unfortunate side effect that is induced by the field personnel: Adding a lot more thinner (probably exceeding the manufacturer’s recommended percentage). Cold paint doesn’t mix as well, it doesn’t pour as well, it doesn’t spray as well and it doesn’t cure out as well. So, while painting during these cooler times is quite acceptable and even recommended, always remember what the product data sheet says for its recommended temperature of the paint itself for optimal application and performance properties. Everyone will better served if the paint temperature is being paid attention to.

Some thoughts as to how to help provide solutions:

Storing material on-site in heated trailers; storing it at the water office or city/municipally owned facilities that are climate controlled; taking smaller quantities home or hotel room (20 or 30 gallons) the night before and storing it there and bringing them back to use for the day. Having a forced air heater on-site and setting paint cans a safe, yet close enough distance away to heat up the material. Infrared thermometers are helpful in measuring the temperature of the paint.

Long Live the Tank!

No comments: