Differences between straw and gun PU foam
Channel: Penosil Official
Date: 2015-04-15

If you are wondering whether to choose straw foam or gun foam then this video will explain it all.

In this video, we demonstrate the use of two construction foams, each with a different dispensing method, in the installation of interior doorjambs.

First of all, for one doorjamb, we use a straw applicator and for the other one, a foam gun.

To apply foam, move smoothly, sealing joints completely with foam, as if welding. Avoid sudden discharges of foam. When sealing wide joints, move the nozzle in a zigzag pattern.

The advantage of gun foam lies in its precise and flexible application method – you can dispense exactly as much foam as needed and then close the cap. Gun foam is highly stable in joints. An alternative to gun foam is straw foam, shown on the left: its application is more complicated, too much foam is discharged and it tends to expand in joints.

You can clearly see that foam dispensed with a straw applicator has expanded in the joint. Due to its high post-expansion, foam dispensed with a straw applicator exerts outward-directed pressure on the doorjamb and, as a result, may break the doorjamb. Also, traces of expanded foam can be seen around the doorjamb. As a rule, however, gun foam seals joints evenly and does not expand significantly.

Next step is to remove the upper, cured foam layer.

Using straw foam is rather uneconomic in this type of joints. In comparison with gun foam, a considerably larger amount of straw foam had to be used.

To clean an empty gun foam can and gun nozzle, use a special-purpose Penosil Premium Foam Cleaner.

Quickly unscrew an empty can from the gun.

To clean the gun’s interior, screw the gun to the adaptor of the can of Penosil Premium Foam Cleaner, similar to that of the foam can. Point the gun nozzle in a garbage bin and press the trigger until cleaner released from the gun is completely foam-free.

Spray the cleaner on contaminated surfaces.

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