When should alcohol-resistant foam be used?

12 fatal mistakes in handling PU foam and how to avoid them

Possibility Number 1: If it is 1-component PU foam, check whether you have shaken the can enough (approx. 20-30 times). Refer to the package instructions for how much shaking to take.

Option 2: 2-component PU foam may not have been shaken enough and / or the hardener (activation dial on the bottom of the can) was not activated correctly or not at all. It is typical here that the hardener was turned in the wrong direction or not far enough. How the hardener is activated exactly differs from manufacturer to manufacturer. The instructions on the package provide more information.

Option 3: If you are working with a gun foam, there are other options:

  • The PU foam gun used and the can do not match. Then the valve does not open at all or only partially. In this case, just use a suitable pistol.
  • The gun used is dirty and the foam cannot escape as a result. The only thing that helps here is to clean or replace the PU foam gun.
  • The opening ball in the gun is stuck and the valve cannot open as a result. This happens when the pistol has only been briefly cleaned with acetone after its last use. In this case, you can try carefully using a toothpick to loosen the opening ball of the PU foam gun. Under no circumstances should you work on the can valve with tools.

Option 4: The can valve itself is stuck, for example because the PU foam can was stored incorrectly. In this case you have to take a new can! You should never try to force open a construction foam can. The can can easily be damaged in such a way that its contents suddenly escape. In the best-case scenario, this means irreparable contamination, and in the worst-case scenario, injuries for you.

Option 5: A PU foam can can also be too cold! The colder it is, the tougher the PU prepolymer becomes in the can and can no longer escape as easily. It is best to protect your cans from the elements. If it has already gotten too cold, you can slowly heat it up in a water bath. But please be careful! If a can is heated too quickly and too strongly, the gas in the can expands too quickly - this can lead to explosions! Immersion heaters, Bunsen burners or even a hot heater are taboo when handling pressurized gas cans!

Option 6: The can used is too old. You can easily tell whether a construction foam can is overlaid by shaking it. If the contents are liquid, the foam is okay. If it feels tough when you shake it, the can is too old.