WeatherBloc Insulating Paint by Mascoat Applied to the Exterior Walls

March 31, 2011 - One of the most challenging aspects of building with large metal boxes is how do you keep the inhabitants cool in the summer and warm in the winter?  We spent quite a bit of time looking at insulation systems for the inside and the outside of the building. For the exterior of the building, we found people saying good (and not so good) things about insulative paint coatings. We met with several vendors and had a difficult time believing some of their claims. 

I wanted an external coating that would reduce heat load along with the chance of condensation forming on the inside walls of the containers. The differential in temperature on the outside and inside can be quite dramatic. We actually watched it "rain" inside the container on one cold January morning when a "Norther" blew in early one afternoon.  We opted to use a radiant barrier on our roof deck, so I felt like we needed one on the walls as well. The heat load in the summer on the west and south walls will be substantial, and anything we can do now to help our HVAC system, will be returned in lower AC bills, and happier tenants.

Last month we met with Matt Gardenia, a rep for one of the most respected coatings company in the industry - International Paint.  Matt visited our job site, and listen carefully to our needs.  Unfortunately, his company does not have an insulative paint, but Matt suggested we give a call to a Houston based company by the name of Mascoat. Michael Stelmach, a sales rep for Mascoat came to our office, answered our questions and demonstrated his WeatherBloc coating.  Unlike paint, Mascoat WeatherBloc is a water based acrylic coating made up of air-encapsulated, insulating silica particles that are designed to thermally insulate.

Unlike the others who came before him, Michael went out of his way to undersell his product. No outlandish claims, and lots of examples of success stories with some well-known companies in town. He also invited me to visit his plant and see their operations first hand. I took him up on the offer - I was very impressed with what I saw and the people I met.

We selected the WeatherBloc product, and Mascoat offered to help us with the application in trade for some photos and an instructional video showing how to mix and apply the product.  These are the kind of "Win-Win" situations I look for. On Tuesday, March 29th, Will Conner (their Marketing Manager) and Michael Stelmach came to the job site. Although it was an overcast day with the threat of rain ever present, the dark clouds did not deter them (or even slow them down).

This blog entry will focus on the step-by-step process of applying the WeatherBloc product. It is an easy material to work with, but like most things, there are a number of tips and techniques that professionals use to insure it is applied correctly. Michael and Will were kind enough to share them with us, and we will share them with you. Please keep in mind this blog entry is just a basic guide - for detailed information, please read the application instructions on their web site or talk with a Mascoat representative.

On Tuesday morning the temperature was a balmy 72 degrees at 10:00am. Mascoat recommends that the temperature of the substrate be at least 60°F (13°C) prior to application, so we were well above their guidelines. The Mascoat truck arrived with 25, five gallon pails of WeatherBloc loaded on a pallet. We unloaded it and checked to make sure there were no punctures or tears in any of the containers.

The 5 gallon buckets have an easy open strip on the lid with a small plastic pull tab. Separation of the WeatherBloc coating is natural due to the large amount of insulating particles in it.  The shipment came with a heavy duty paddle which we inserted into a hand drill and set the drill to spin in reverse. We straddled the pail and kept our feet on both sides to stop the pail from spinning.  We stirred the product until it had a milkshake-like consistency (about 20-40 seconds).  Michael cautioned us not to over mix it because that will destroy the insulating particles. 

Next, we turned our attention to the spray rig and spray gun head.  Step one is to open the handle of the spray gun head and remove the filter so the insulation is not filtered out. We used a clean, 5 gallon bucket filled with water to prime the sprayer. We flushed the lines with 10-15 gallons of water to ensure we had removed any existing debris in the lines. Next, we checked the pump to make sure there were no cracks or leaks that could result in lower pressures.

We then moved the nozzle of the sprayer to the Mascoat WeatherBloc bucket.  Michael used a pair of snips to cut a hole in the plastic lid so we could insert the nozzle in keeping the coating moist and free of dirt. With the sprayer tip removed, he pressed the trigger to remove most of the water in the lines. When the product started to flow, he attached the tip to the sprayer head. This step allowed the system to bleed until the pressure was reduced. He pressed the trigger on the gun and used another empty bucket to catch any remaining water in the lines.  In less than a minute, the lines were primed and the sprayer was spraying WeatherBloc. The product was now ready to be used.

Michael set up some of the cardboard packaging that came with the shipment to test the pattern of the gun and to adjust sprayer pressure. We used a large pneumatic sprayer, and the air pressure was set between 80-100 PSI. The idea is to make sure the pressure is only high enough to stop fingering. Michael explained that if pressure was not consistent, it could result in a volume problem with the pump - not enough air would be supplied to the sprayer. Adjustments may be needed to get the pressure right and achieve the correct spraying consistency. He told us to make sure that the unit also has sufficient air flow so it is not starved for power.

With the sprayer adjusted and working properly, he began spraying a section of the building. He reminded us that WeatherBloc is a coating, not a paint and that it is very important to make sure we have an even coat applied throughout the substrate. He showed us how to use a Mascoat thickness gauge to insure we were applying it at 22 mils as required. It was not very humid that day and the wind was blowing at 5mph so the coating dried very quickly. It took four to six passes to reach the required thickness. To test for proper dryness Michael placed his thumb onto a test area of the coating and pressed down. He turned his thumb 90° and remove it. If any coating appeared on his thumb, it was a sign that the coating was not fully dry. It is important to make sure the coating is completely dry before applying subsequent coats.

Michael then handed the sprayer to our crew and made sure we were applying the coating correctly.  I was suprised with just how fast the coating went on - it took just under 5 hours to do the entire building. When it was time for lunch, we took the nozzle off the sprayer head and submersed it in a 5 gallon bucket of clean water. At the end of the day, we used water to clean out the system, and returned the filter to the nozzle head. The next day, we applied a second coat to the South and West sides of the building.  We want to thank Mascoat for all their help and would highly recommend this product for external insulation on any ISBU conversion project. Next week we will select the color (or colors) and paint we will use as the top coat.

Category: Container Building,