How to use the mounting foam with and without a gun: simple tips
Polyurethane foam has long been firmly established in the everyday life of both professional builders and ordinary owners who have a need for minor repairs. This is due to its versatility and very valuable qualities: ease of application, good adhesion to most surfaces, hermetic filling of joints and cavities. If you are a beginner, you should learn a few simple recommendations on how to use the mounting foam.
Key useful rules
Despite the versatility of use, the material requires careful action. With the general simplicity of the instructions, you need to have the skill of handling and choose the right mounting foam.
What foam to buy
Like any other popular product, mounting foam is produced by everyone. There are players in the construction market, whose experience in the production of polyurethane filler has tens of years. Usually they can be distinguished by an impressive price tag. In addition to them, on the shelves you can find a huge number of multi-colored cylinders, the cost of which is lower, but the quality is in question. In this segment, the rule “the more expensive the better” is still in effect more than half the time, and there are several reasons for this:
- The actual yield of the finished foam. On professional foam, there is a figure for the approximate volume of contents after emptying the container. On cheap cylinders such information can also be found, but it may not be true. It's a shame, having bought a cylinder for a small area of work, then run for another one, because the material turned out to be much less than the declared.
- Secondary expansion coefficient. Builders really appreciate when this indicator is low. This means that after leaving the packaging, the foam expands almost instantly, and after that it gradually increases in volume by less than half. Poor-quality foamed polyurethane inflates two to three times, which can lead to deformation of surfaces and displacement of parts.
There are other surprises that a buyer of poor-quality goods may encounter - poor adhesion, slow drying, increased toxicity, and more. Distinguishing a good mounting foam from a bad one can, alas, only during operation.
How to apply
Before starting work, the surfaces with which the foam will come into contact should be cleaned and moistened with water as much as possible. The more humid the air around, the faster the material will set.
Fill the seams and cavities no more than half - an expanding substance will fill the rest. Vertical voids fill from bottom to top. The wider the space where you want to apply the foam, the stronger it is to feed it, and it is better to make zigzag movements so that the extruded foam holds better.
During the first use of the polyurethane filler, troubles in the form of precipitated fragments and uneven filling are inevitable. You need to remember that you can’t touch the foam, as well as pick it up with your hands or try to wipe it immediately. Better lay something down or wait for drying, then removing the dried substance will be much easier. Work with gloves, as polyurethane is very long and difficult to peel off from the skin.
How to use gun foam
A special mechanical device allows you to work with foaming material faster, easier and more convenient.Do not be too lazy to get a good functional construction gun - so you can do everything better.
Choose a gun with a dispenser - this is a special wheel on the opposite end from the nozzle exit, it can adjust the foam flow to fill narrow or wide joints. The device itself should look solid, not hang out and rattle.
Using a gun is very simple - you need to screw the neck of the bottle into the socket until it stops, adjust the feed with a screw, and then, pulling the trigger, drive the nozzle with the nose, leaving behind a “sausage” made of foam polymer. Try not to push the trigger, otherwise the material under pressure may break out in an amount greater than what is needed, and it will be possible to remove it only after drying.
How to apply polyurethane foam with a tube
If we are talking about one-time use, and even in small quantities, the gun may turn out to be useless. It is for such cases that manufacturers provide cylinders in their product lines that do not need any additional device. The application mechanism in this case is extremely simple: a special plastic trigger with a transparent tube is put on a threaded or collet connection of the cylinder. Shaking the balloon well and turning it upside down, pull the trigger, and pressing harder or weaker, squeeze the contents through the tube to the right place.
If you adapt, then you can use a standard nozzle no worse than using special equipment, but still it is worth remembering that it is designed for one-time use, but you also need to spend time and material to fill your hand.
Do not save when buying foam or a gun if you do not want to swear later during the application process. The more inexperienced the user, the better tools and materials should be.
