Working with Spray Foam in Cold Weather
Every year, as the leaves change colors, the air becomes crisper, and as the holiday season approaches, temperatures drop and sometimes we forget what kind of impact the colder weather can have on spray foam operations.
Imagine this situation:
Your spray foam installer gets to work, comfortable and relaxed, ready to start his day. But the diesel generator will not start; it is cold and someone forgot to plug in the heater. He goes inside where he is yelled at by his supervisor for not plugging it in the day before, and is instructed to finish the job no matter how long it takes. Before he gets started, he now knows that he is faced with a long shift, causing the once relaxed employee to now become tense at the thought of working for a copious amount of time. You get the picture, right?
An hour behind schedule, he finally starts the generator and leaves for the jobsite. Once he arrives, he realizes, in his haste, that he forgot to stop to fill the diesel tank that he knows won’t last the day. Another delay, another frustration. Once he gets the generator running, he turns on the air compressor and notices that no air is coming out, resulting from the moisture in the tank from the day before that froze overnight. Now, there’s even more frustration!
You’ve heard the story of the man who kicked the cat, right? Well, the installer just became the man who throws the spray gun against the wall, or smashes the gears in the truck.
But it doesn’t have to be this way. There are ways that you can minimize these cold weather issues.
Regardless of the equipment you use, an electric or hydraulic proportioner, or a box truck or trailer, the truck workspace should be kept warm at all times. Both insulating and heating the enclosed space will help control temperature. If the temperature is not controlled, the temperature inside the work area will be the same as outside, and this means that all of the equipment, including hoses, chemicals, cleaners, grease, hydraulic fluid, black piping, generator, diesel fuel, air compressor, parts, etc. will become dramatically colder. And when the equipment and chemicals are cold, they are much more difficult to work with.
First, let’s talk about proportioners, since there is a big difference between electric and hydraulic proportioners. Have you ever heard your hydraulic pump make a high whining noise? Well, this is a tell-tale sign that something isn’t quite right and you should not continue to operate until the problem is identified.
In cold weather, this could occur if the hydraulic fluid is too cold, which means it is too thick and the pump could become damaged. If you find yourself with this problem, you have to heat the hydraulic fluid in order for the pump to operate properly.
If the pump is damaged it could mean:
Replacing an expensive hydraulic pump
Downtime from waiting for the new pump to be ordered, shipped, and received
Installation time and cost (But, do you know how to do this yourself?)
Solution: To eliminate this problem, keep your equipment warm during cold weather.
Next, the fluid pumps that transfer the chemical from the drums to the proportioner is probably either a diaphragm pump, such as a Husky 1040, or a stick pump (also called a drum pump or transfer pump), like a Graco T1 or T2. The diaphragm pump is usually mounted on the interior wall just above the chemical drums and has a dip tube that goes into the drum. The stick or drum pump is usually screwed into the bung opening on a drum. The cold weather affects the diaphragm pump more than it does the stick pumps.
The diaphragm pump works because two rubber membranes move back and forth, causing a vacuum inside the pump. This vacuum pulls the liquid from the drum through the pump and feeds the equipment. In a warm environment, these diaphragm pumps work well. However, most liquids, including spray foam A-side and B-side material, become thicker and thicker as the surrounding temperatures go lower and lower. So, if the chemical temperature is too low, resulting in the material being too thick, the diaphragm pump will not pump it.
Solution: Keep your equipment and chemical warm during cold weather.
Then there are the hoses. Even if you have a closed trailer operation, as you should in colder weather, your hoses have to span the length from your rig to the building, meaning that they have to be outside even when it is cold. However, it is important to maintain the chemical temperature from the machine to the tip of the gun, so heated hoses are very important. One of the most important things to know is the location of the hose thermocouple, or Fluid Temperature Sensor (FTS), which should be located as close to the gun as possible. This means that the temperature will be measured close to the gun and reported back to the “brain” of the machine to maintain the temperature as close to the target temperature as possible.
Here are some tips:
Find your FTS and move it as close to the gun as possible.
Find out the length of your hose. Most proportioners can handle 50 to 300 feet of hose. On older machines, you have to manually change a tap setting if your hose length changes for any reason. On more modern machines, the hose length may be detected and adjusted by the equipment. Find out which one you have.
When getting to a jobsite, make sure to position the rig as close as possible to the entrance point of the project; this will limit the length of the exposed hose in the cold weather.
Protect the exposed hose from the cold weather. For example, you can wrap the hose with blankets or batt insulation and/or rest the hose on wood pallets; getting the hose off of the ground
Another piece of equipment to be wary of in these conditions is the spray foam gun. Most spray guns are basically the same; and as big hunks of metal, they lose heat quickly and generally become cold in chilly weather. O-rings become brittle, lubricating oil and grease become thick like cold honey or cement, and gun grease hardens. These are all used to lubricate and protect moveable parts, yet if they get cold and become stiff, then they may fail. If you pull the trigger under these conditions and failure occurs, you may end up with a crossover, or a total foam blockage at the head of the gun. This can become very troublesome and is an expensive fix in terms of parts, the labor to repair the tools, as well as the downtime that will occur.
Solution: Keep the spray guns warm during cold weather. If you don’t have a heated rig, travel with the foam gun in the cab of the truck in the warmer air.
Finally, there is the liquid chemical. Like any liquid, when iso gets cold, it becomes thicker. Not as quickly as the resin, but it does get thicker, and can possibly freeze. As iso approaches freezing temperatures, the molecules get close together and can attach to one another, resulting in dimers, which are also called crystals. When freezing, iso will not solidify like an ice cube but will become more like a slush. These crystals can ruin the iso material and damage your equipment. If you use this material, you could plug up and clog your entire system from the drum to the gun, which can also turn out to be a costly situation if you factor in equipment repair and loss of time and revenue.
However, in some cases you can save the iso by straining the crystals. To do this you need a clean barrel and a large straining material, such as a wire mesh, cheesecloth, a large pair of panty hose, or something that allows liquid to flow through it that will catch solid particles. Then, you have to transfer the liquid by hand, which can take a while, and pour it over the strainer to drain the liquid into the new drum. Keep in mind: You can’t pump the chemical because of the crystals.
Resin will generally be more affected by cold weather than iso, causing it to become thicker, faster as the material gets colder. Additionally, the resin for water blown foam can freeze into a solid mass due to the water content. The good news is that at least with most water blown foams, you can typically thaw out the material and use it. So, if you accidentally freeze the resin, make sure to contact the manufacturer for the best advice with their material.
However, in general, it is important to maintain the resin temperature for optimum performance. Drum blankets and band heaters can work if placed at the very bottom of the drum and are thermostatically controlled. Remember that when using a band heater, if it goes wild and overheats, it can blister the drum liner and the debris can break off into the resin and end up in one of the screen filters or down the line in the hose.
Solution: Be proactive and keep your chemicals warm during cold weather. Do not let them get close to freezing.
By now you are probably noticing a theme—protect your equipment, gun, hoses, and chemicals from the cold weather. When you keep everything warmer, the process will become easier—it may not be easy, but it is easier than working with spray foam in the cold weather.•
About the Author: Robert Naini has a Bachelor’s of Science in Mechanical Engineering and an MBA from the University of Texas in Arlington. With more than a decade of experience on the cutting edge of spray foam insulation, he has helped hundreds of owners and managers grow their business with a unique knowledge base including spray foam sales and marketing, employee and applicator training, building science awareness and building code expertise. Spray Foam Advisor offers web-based training and education, with videos, articles, blogs and more, to help solve problems for spray foam professionals and the construction industry.
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