How to Identify

Shrinkage may occur laterally, on either side of a wall cavity. It can also occur front-to-back with shrinkage back to the substrate. Front-to-back shrinkage is more difficult to notice during install and requires attention.

Shrinkage may be minor, where the foam delaminates slightly from the sides of the studs. Severe shrinkage can also occur, producing gaps of an inch or more.

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How to Correct

If shrinkage occurs immediately (less than a minute after application), then the foam is probably too hot. Dial back the temperatures in 3-degree increments until shrinkage is eliminated.

If shrinkage is delayed, that is usually a sign of pressure imbalance and the foam is off ratio. Check your proportioner gauges to make certain A and B side pressures are balanced. If they are not balanced, see B-side Supply Clog below. If they are balanced, see B-side Delivery Clog below.

A-side Supply Clog:

• Verify correct inlet pressure to the proportioner at inlet pressure gauge. Refer to pump manufacturer for proper inlet pressure specifications. If pressure is too low, the pump or transfer hose may be clogged. Check for obstructions. You may also need to repair/rebuild the upper or lower section of the pump.
• The viscosity of foam can also restrict flow rates. Cold chemical may not achieve proper pressure until it is warmed.

A-side Delivery Clog:

• Check Proportioner Y-Strainer - Remove screen and clean/replace as necessary.
• Check Gun Block - Disconnect and confirm no clogging in the block. A cross-over of chemical can also clog the block.
• Check Gun Screens - Remove screens and clean/replace as necessary.
• Check Mixing Chamber - Remove chamber and confirm offices are clean and clear. Clean out accordingly with proper sized drill bit and pin vise. Also confirm there is no scoring where the side seals contact the mixing chamber; the chamber may need to be replaced. Once the chamber is inserted back into the gun, make certain no chemical mists out from the gun when the chamber is not engaged.

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Settings

The A-side, B-side, and Hose Heat must maintain temperatures within the following range for proper results:

A/B/Hose Temp

How to Identify

Foam is usually too hot and setting up too quickly. Instead of off-gassing through the front in a normal reaction, it will off gas at the rear and push itself off the wall. This is often invisible to the sprayer and it's important to inspect foam during the install. Check the foam by firmly pressing or lightly pounding on the foam to make sure there is not a hollow cavity between the foam and substrate.

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How to Correct

Reduce temps temperature in 3-degree increments. Test spray areas until the visual signs of hot foam no longer exist. As you adjust the temperature, be aware that much of the chemical within the hose most be sprayed before the you will see the new temperature results at the gun. This is why you do not want to make drastic temperature adjustments at once.

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Settings

The A-side, B-side, and Hose Heat must maintain temperatures within the following range for proper results:

A/B/Hose Temp:

Other Considerations

Moisture and dust/debris can also create adhesion issues. Keep a moisture meter and leaf blower on your rig. Check to make sure moisture content is below 15%. Use the leaf blower to clean debris from wall cavities and areas where foam is being installed.

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Pro Tip

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

You should not experience poor yield without other symptoms. Familiarize yourself with the Foam Reaction section of this app to better diagnose what may be causing your yield issues. If you are still experiencing low yield with no other symptoms, contact your Enverge representative.

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Pro-Tip

‍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 (i.e. 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 are usually due to a pressure imbalance or scratches on the mixing chamber.

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Pro-Tip

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.

How to Identify

Chemical from either the A or B side has crossed to the other inside your gun, and possibly back up the hose line. This requires a gun rebuild and may require a whip replacement.

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How to Correct

Gun crossovers are the result of an imbalanced chemical pressure and flow through the gun. Check your proportioner gauges to make certain A and B side pressures are balanced. If they are not balanced, you can usually chase down the clog in on the side with a lower pressure reading.

Supply Clog:

• Verify correct inlet pressure to the proportioner at inlet pressure gauge. Refer to pump manufacturer for proper inlet pressure specifications. If pressure is too low, the pump or transfer hose may be clogged. Check for obstructions. You may also need to repair/rebuild the upper or lower section of the pump.
• The viscosity of foam can also restrict flow rates. Cold chemical may not achieve proper pressure until it is warmed.

Delivery Clog:

• Check Proportioner Y-Strainer - Remove screen and clean/replace as necessary.
• Check Gun Block - Disconnect and confirm no clogging in the block. A cross-over of chemical can also clog the block.
• Check Gun Screens - Remove screens and clean/replace as necessary.
• Check Mixing Chamber - Remove chamber and confirm offices are clean and clear. Clean out accordingly with proper sized drill bit and pin vise. Also confirm there is no scoring where the side seals contact the mixing chamber. Resurfacing with 600/800 grit sandpaper may correct the issue. Be sure to place the sandpaper on a perfectly flat surface.  If scoring is too deep, the chamber may need to be replaced. Once the chamber is inserted back into the gun, make certain no chemical mists out from the gun when the chamber is not engaged.

How to Identify

Small amounts of hardened ISO crystals will be observed in the proportioner and/or gun screens.

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How to Correct

Crystallization is caused by water / moisture intrusion into the ISO system. If minimal amounts of crystallization occur, it may be a humidity issue and can be corrected with a desiccant drier cartridge attached to the recirculation hose.

If larger amounts of crystallization are seen, there may be water intrusion. Water usually enters through the drum. Sometimes this can be caused by spillage on the drum or condensation forming on the transfer pump. If water is observed coming out of transfer pump, the rig air dryer is probably not working. It's also important to make sure the pump collar is screwed into the drum bung. Lack of a proper seal can allow moisture to enter the drum.

Check the air dryer. If an electrical air dryer is being used, make certain it is getting power and is turned on. Most dryers have an automatic drain. These drains can stop working, so check to make sure it is draining properly. Also check air filters on the air dryer, if applicable. If your air compressor has a tank, make sure it is drained and free of water.

An imbalance in pressure is usually the result of blockage in the system. This creates off-ration foam that significantly reduces yield and thermal performance. It is important to identify which side (A or B) is clogged, then to chase down the issue by checking the Supply and Delivery systems of the line where the clog has occurred.

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How to Correct

Check for a clog on the side (A or B) that is showing a lower pressure.

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Supply Clog:

• Verify correct inlet pressure to the proportioner at inlet pressure gauge. Refer to pump manufacturer for proper inlet pressure specifications. If pressure is too low, the pump or transfer hose may be clogged. Check for obstructions. You may also need to repair/rebuild the upper or lower section of the pump.
• The viscosity of foam can also restrict flow rates. Cold chemical may not achieve proper pressure until it is warmed.

Delivery Clog:

• Check Proportioner Y-Strainer - Remove screen and clean/replace as necessary.
• Check Gun Block - Disconnect and confirm no clogging in the block. A cross-over of chemical can also clog the block.
• Check Gun Screens - Remove screens and clean/replace as necessary.
• Check Mixing Chamber - Remove chamber and confirm offices are clean and clear. Clean out accordingly with proper sized drill bit and pin vise. Also confirm there is no scoring where the side seals contact the mixing chamber. Resurfacing with 600/800 grit sandpaper may correct the issue. Be sure to place the sandpaper on a perfectly flat surface.  If scoring is too deep, the chamber may need to be replaced. Once the chamber is inserted back into the gun, make certain no chemical mists out from the gun when the chamber is not engaged.

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Pro Tip

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.

There are 3 primary temperature considerations when setting up to spray foam:

1. Starting temperature of the chemical inside the drum.
2. A/B side heater temperature settings on the proportioner.
3. Hose heat settings on the proportioner.

Recirculating chemical prior to spraying is an important step to make certain the chemical in the drum is at the correct starting temperature. One of the most critical considerations in colder weather is the Δ-T (i.e. delta T), or the proportioner's ability to increase chemical temperatures. If your chemical is not heated to the correct starting temperature, the A/B heaters will not heat chemical adequately to the set point. This becomes amplified in cold environments.

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Pre-Heat Temp

Check the drum temperatures with an infrared thermometer by shooting the lower side of the drum. Makes sure they are to the proper temperature.