PU Foam Procedure

PU Foam Procedure

Protection Wear: Always wear gloves, safety glasses, and a mask.

Shaking the Can:

Before use, shake the can vigorously for at least 20-30 seconds to ensure even mixing. It is normal to hear the stirring ball (if present) rolling inside the can.

Shake again for 10-15 seconds after each break and before resuming use.

Installing the Spray Hose:

Remove the protective cap from the top of the can.

Tighten the supplied plastic spray hose clockwise onto the valve connection on the can. Ensure it is securely tightened to prevent leaks.

Test Spray (Optional but Recommended):

After initial use or after replacing the spray hose, spray a small amount onto cardboard or a garbage bag to observe the foam (color, texture, and foaming speed). This will also help you become familiar with the trigger pressure and foam flow rate.

Start Filling:

Invert the can! This is the most critical operation! Only when the can is inverted (with the valve facing down) can the propellant gas inside effectively push the liquid out.

Insert the tip of the nozzle into the gap or hole you want to fill.

Slowly and evenly pull the trigger to allow the foam to flow.

Controlling the Filling Amount:

Better to use less than more! Foaming adhesive will continue to expand after being sprayed, typically expanding to 2-3 times its original volume or even more (see product instructions for details).

For deeper gaps, it’s recommended to fill in two or three batches: first filling about 1/3 to 1/2 of the gap’s depth, then allowing it to initially cure and expand (a crust forms on the surface, about 10-30 minutes), before applying the second batch. Avoid filling the entire gap at once, which may result in insufficient expansion or excessive expansion pressure.

For wider gaps (wider than 5cm), it’s recommended to first insert some insulation board, foam strips, or similar material into the center of the gap as a backing before foaming the surface. This saves material and ensures a more effective filling.

Generally, aim for about 1/3 to 1/2 of the final desired filling volume, leaving ample room for expansion. Imagine it eventually filling that space.

Filling Tips:

Fill from the deepest part of the gap outward: For deep holes or long gaps, extend the nozzle as far as possible, moving it slowly and evenly outward while creating foam.

Keep the nozzle moving: Avoid spraying at one point for a long time, which can cause excessive accumulation.

Vertical gaps: Fill from the bottom up, utilizing the foam’s own upward force.

Complex shapes: Fill in sections or areas.

Stop spraying: Once the estimated fill level is reached, release the trigger to stop spraying.

Clean the nozzle immediately (Important!):

Immediately remove the nozzle from the can counterclockwise.

Flush the nozzle with detergent (special detergent or acetone) from the rear end of the nozzle forward until the liquid flowing out of the nozzle is clear. Alternatively, simply soak the front end of the nozzle in a bottle of detergent.

If the nozzle is clogged or not cleaned thoroughly, it will be unusable the next time! For unused cans, spray a small amount of detergent on the valve opening and replace the original protective cap (if it can be replaced).