One-component polyurethane foam is a versatile product that expands as it dries. It is used to fix, caulk, insulate, glue and soundproof most traditional materials.
Practical advice
If the aerosol valve becomes blocked after a long period of non-use, do not force it to unblock it to avoid the risk of splashing. Unscrew the end of the cannula and clean with acetone.
Store the aerosol in a cool, dry place. It must remain in an upright position, otherwise the valve may malfunction. Visit https://sprayfoamequipment.co.uk/ for all the options now.
Insulate, fill, fix
Patching a crack, caulking a pipe passage, sealing a junction box or a door or window frame… polyurethane foam has multiple applications. It is suitable for any soundproofing and thermal insulation operation (water pipes against frost, hollow bodies in boats, caravans, etc.), but also for filling cavities. It also makes it possible to fix certain elements (roofing, for example) or to glue materials.
Qualities of expanding foam
Usable indoors and outdoors, it has very good adhesion to most materials : concrete, plaster, brick, metals and plastics. On the other hand, it is ineffective on polyethylene, polypropylene, glass, silicone and Teflon.
Its insulating and phonic qualities are excellent. It is estimated that 1 cm thick foam is equivalent to 40 cm concrete.
The chemical reaction (polymerization) which transforms the liquid polyurethane into a semi-rigid foam takes place under the influence of humidity in the air or thanks to the addition of water. Its expansive power is high: 0.5 l of liquid polyurethane makes it possible to obtain an average of 20 l of foam.
How to use polyurethane foam?
To speed up the polymerization and achieve faster hardening of the foam, the surfaces should be moistened, for example with a small hand sprayer. Wearing glasses is recommended to protect against possible splashes of liquid foam.
- The polyurethane is packaged in an aerosol can with a capacity of 300 or 750 ml.
- Before extrusion, shake the container 20 to 30 times to homogenize the product.
- Position the end of the hose at the entrance to the cavity to be filled. Gently press the tip that controls the valve while holding the aerosol upside down. There are “all positions” bombs, which are very practical but more expensive to buy.
- The cavity should be half-filled, never completely because the foam expands tripling in volume during its setting.
- Proceed in small doses, even if it means adding product later. Be careful, the expansion is powerful and can distort the joinery.
- Allow the foam to “swell” and infiltrate into inaccessible cavities. The surface drying takes place in about a quarter of an hour, but the core setting requires about twelve hours, depending on the thickness, the temperature and the ambient humidity.
- Once dry, the foam can be cut, coated or painted for the perfect finish.
- After use, the valve and cannula are cleaned with acetone.
Fill electrical ducts with expanding foam
Expanding foam: protection of electrical ducts
The bleedings of the electrical ducts are often filled with plaster, but the drying remains long. The foam fills the cavities and blocks the ducts and receptacle or junction boxes.
Fill a crack with the foam
Fill the holes with the expanding foam
The small space between the top of a plaster tile partition and the ceiling is difficult to seal with conventional materials. The injected foam advantageously replaces them.
