Chemical Drum Temps

Pre-heating chemical can be a time consuming part of the spray foam process. Finding ways to reduce this needed time is extremely valuable. Many rigs are equipped with auxiliary power and heating tools that can be plugged in during extended periods of down time and overnight. Use these auxiliary heating tools to keep your chemicals warmer prior to the pre-heat process, resulting in a shorter period of time needed to reach the required temperature for spraying.

Minimize Waste

Follow the sun to reduce waste from heat loss. As we know, heat aids in the chemical reaction of foam. This includes the temperature of the substrate and the ambient temperatures within the spray environment. The eastern side of a building will heat earlier in the day, while the western side of the building will remain warmer later in the day. Use this to your advantage by starting on the eastern side of the building in the morning and following the sun throughout the day.

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Overspray Prevention

Use "flags" and "targets" to monitor wind conditions and overspray risk throughout the day. This simple proactive approach can save you thousands of dollars in damage. Consider this for exterior applications, along with interior applications where window and door openings remain open during install. A wind tunnel can occur on the interior of a building, carrying overspray outside.

• Flags made of caution tape can be attached to equipment, building structures, and on scrap wood stakes in the ground. The key is to place multiple flags around the job site, allowing you to monitor wind from different angles. Visibility is key, so make certain these flags can be seen by the sprayer and/or helpers. When the flags are blowing, take the necessary precautions, or stop spraying.
• Targets can be made out of scrap pieces of cardboard or plywood. Paint with black spray paint and place at locations around the job site where spray foam is being applied. The black paint allows for easy visibility of overspray droplets. Multiple targets at varying distances from the spray location can allow you to measure how far overspray is traveling. If overspray is seen on the targets, take the necessary precautions or stop spraying.

Environmental Concerns

Be cautious when heating the ambient temperatures within a space. Using a diesel or kerosene heater is typically a better option than using propane. Propane heaters can increase moisture and relative humidity within a space over a shorter period of time. Higher moisture levels can lead to issues in the spray foam manufacturing process. It is wise to add heaters in the first steps of prepping a job site. Heat the area while chemicals are being recirculated and the job site is being prepped. Make certain all heaters are turned off during the install process.

Cold Foam

Not only is the ambient temperature within the spray environment a needed consideration, so can be the substrate temperature and the material of the substrate. For example, metal and concrete are typically colder than wood and can actually absorb some of the heat from the chemical as it is applied. To correct this, the substrate can be heated or a flash coat (i.e. a very thin first coat) foam can be applied to heat the substrate before applying the full lift coat.

Hot Foam

Heat chemical until you begin to see signs of Hot Foam, then back down temps slightly to achieve desired appearance and chemical reaction. This can be a good technique to maximize yield for the specific environment and conditions.

Poor Adhesion

On the rare occasion poor adhesion could be related to off ratio foam. See Resin Rich foam in the Foam Reaction section for information on identifying and correcting this issue.

Poor Yield

Did you know that smaller mixing chambers lead to a longer "dwell" time, leading to higher yields. The dwell time is defined as the amount of time the chemical is in contact with the proportioner heating elements (ie. the primary heaters).

Longer dwell times allow for a more consistent Delta T. When chemicals are flowing quickly through the system, the dwell time is much shorter and the heaters are less effective, especially on older equipment. Your chemicals may start to show signs of Cold Foam if starting drum temperatures are lower. Make certain drums are heated to the correct starting temperatures to prevent this. Using a smaller mixing chamber will also help.

Gun Leaks

If pressures are set low with lower temps and a bigger mixing chamber, you may see ISO and Resin spray out of the chamber without properly mixing. Sometimes these lower temp and pressure setting may be useful in delicate install scenarios. situation. However, it's important to make certain a smaller chamber is used. Larger mixing chambers do not force the chemicals to mix as well as smaller chambers do.

Pressure Imbalance

Machined materials that are known to be perfectly flat, are the best surfaces to sand against with resurfacing the mixing chamber or side seals. Glass and granite are both common and acceptable surface materials. Some machined cast iron can also be effective, so long as it is not distressed from wear.