FOAMING AGENT

Foam not dispensing, poor discharge, or excessively thin foam

Causes:

1. Low temperature: Foam is very sensitive to temperature. When the can temperature is below 5℃, the internal pressure is insufficient, making it difficult to dispense.

2. Insufficient shaking: The can was not shaken thoroughly before use, resulting in uneven mixing of the prepolymer and gas.

3. Clogged valve: The nozzle or spray gun was not cleaned promptly after the last use, causing blockage.

Solutions:

1. Warm water heating: Immerse the foam can in 30℃-40℃ warm water for 10-15 minutes (do not use boiling water or open flame to avoid explosion).

2. Thorough shaking: Before use, vigorously shake the can up and down for at least 1 minute (approximately 60 times or more) until you hear the internal steel balls clicking.

3. Cleaning and unblocking: If it is a gun-type foam dispenser, check if the spray gun is clogged. If necessary, use a special cleaning agent to unclog it.

Foam shrinks, collapses, or has voids after curing

Causes:

1. Low ambient humidity: Foam needs to absorb moisture from the air to cure; dry air can lead to poor curing or shrinkage.

2. Applying too thick a layer: Applying too thick a layer prevents the interior from contacting moisture after the outer layer cures, resulting in incomplete curing or shrinkage later.

3. Dry substrate: The surface was not moistened, leading to poor curing at the bottom of the foam.

Solutions:

1. Spray water before application: Before applying the sealant, lightly spray water into the gaps (keep them moist but not waterlogged).

2. Layered filling: For wider gaps, fill in two layers. The first layer fills 1/2 to 2/3 of the gap depth, and the second layer is applied after the first layer has cured.

4. Spray water after curing: After applying the sealant, spray a small amount of water mist onto the foam surface to accelerate curing.

Foam becomes brittle, powdery, or lacks strength

Causes:

1. Product quality issues: Inferior or expired expanding foam was purchased.

2. Sun exposure: Prolonged exposure to ultraviolet light (sunlight) after curing will cause the expanding foam to age rapidly, yellow, and powder.

3. High temperature: High ambient temperature (above 35℃) during construction leads to excessively rapid reaction and a coarse cell structure.

Solutions:

1. Protective measures: Expanding foam is not resistant to ultraviolet light. After curing and cutting, the surface must be covered with cement, sealant, or paint for protection.

2. Purchase genuine products: Check the production date, choose reputable brands, and avoid using expired products.

3. Environmental control: Construction should ideally be carried out in an environment between 5℃ and 35℃.

Expanding foam stuck to hands, clothes, or door/window frames (the most difficult problem to remove)

Note: Once expanded foam hardens, it is extremely difficult to remove.

Solutions:

1. Before hardening (when soft):

* Skin: Immediately wipe with a dry cloth, then wipe with acetone (the main ingredient in nail polish remover) or a dedicated expanding foam remover, and finally wash hands with soap and water.

* Object surfaces: Quickly wipe with a cleaning agent.

2. After hardening (when hard):

* Skin: Solvents are ineffective. Only soak in warm water and gently scrub with a scrubbing soap or pumice stone. It usually takes several days for the stratum corneum to metabolize and completely remove the foam.

* Object surfaces: Only carefully scrape with a utility knife. Residual traces can be gently wiped with a cleaning agent or banana oil (Note: Use solvents with caution on some plastic or painted surfaces to avoid corrosion).

The glue gun for expanding foam fails to dispense glue or leaks glue.

Causes:

1. Adjusting nut locked: The flow adjustment nut at the rear of the glue gun is too tight.

2. Internal blockage: The glue inside the gun barrel has hardened due to lack of cleaning over a long period.

Solutions:

1. Adjust the flow rate: Rotate the adjusting nut at the rear of the glue gun counterclockwise to loosen the flow control.

2. Regular cleaning: After each application or when changing the glue canister, hang a dedicated cleaning agent upside down on the glue gun and rinse the nozzle and barrel until the liquid flows out clearly.

Construction Tips

1. Safety First: Always wear gloves and goggles before application, and lay newspaper or plastic film on the ground to prevent dripping.

2. Inverted Use: Whether using a gun or tube, the can must be inverted (valve facing down) during use; otherwise, only gas will be dispensed.

3. Allow Expansion Space: Expanding foam will expand in volume after curing (ordinary foam expands by about 50%-100%). Do not fill it too full to avoid compressing and deforming door and window frames.