Foam cylinders are sold with a special adapter for mounting, but the standard sprayer does not allow responsible work, since it does not provide for a dosage limitation of the incoming foam. To ensure the quality of installation, it is recommended to purchase a device called a foam gun, the design of which makes it possible to adjust the pressure and volume of the liquid.
Different models of mounting guns do not differ significantly in design among themselves - the device layout for all of them is approximately the same. The main features by which it is customary to classify them are the purpose (for domestic use or as a professional tool) and the material of manufacture.
Professional models are made of metal, they have the ability to disassemble for subsequent detailed cleaning, and household products are made of plastic, most often without the possibility of disassembly.
Gun device
The design is simple and consists of the following mechanisms and parts:
- housing (metal or plastic);
- trunk;
- needle rod;
- trigger on the handle;
- nozzle (use of removable nozzles with various characteristics is possible);
- gearbox with valve for cylinder installation;
- an adjusting screw that allows you to change the path of the trigger mechanism, which makes it possible to control the amount of foam leaving the device.
If you look at the drawing of the gun in the context, you will notice that the diameter of the barrel is slightly larger than the diameter of the needle rod. It is in this cavity that the foam from the cylinder comes under pressure.
How to choose
In order to decide which and how to choose a gun for polyurethane foam, you should first decide what work it will be intended for. If you need to perform a one-time job, then it is better to opt for inexpensive plastic devices that will not be a pity to throw away after the work is completed.
In the event that you have to work with foam professionally, it is recommended to pay attention to serious brands with the appropriate level of characteristics.
An important point in the purchase of a gun is to determine the reliability of the valve, and therefore it is recommended to immediately check the novelty for leaks whenever possible, filling the gun with liquid to clean the device. The cleaner will not leave any traces, but will allow you to find out how much the product is ready for use.
If you have to do housework or in the country, there is no point in buying a professional model. It is enough to take a cheap plastic tool.
When buying a gun for professional activities, it is advisable to choose metal models. Also, you should make sure that the supplier always has spare parts for the device so that it does not have to be replaced then with minor damage.
Such pistols will need to be thoroughly cleaned, which is why the question of the possibility of a simple and convenient disassembly of the structure is also important.
Popular models and their prices
Among the professionals, the following products are included in the rating of the highest quality:
- Hilti. This manufacturer offers models for home use and for professional builders. Prices range from 650 to 1200 rubles.
- Bison Under this brand, all-metal pneumatic guns, including those with a Teflon coating, are produced. The cost is from 400 to 1350 rubles.
- Blast. Convenient and lightweight aluminum pistols with a plastic handle, easy to use, additionally equipped with interchangeable nozzles. The cost is within 700 rubles.
- Kraftool. Pneumatic guns of this brand allow you to work with high accuracy, as they clearly regulate spraying. Prices from 500 to 1150 rubles.
- Soudal. This manufacturer produces models for professional builders. The cost is from 1200 to 1600 rubles.
- Workman. Metal guns that can be used for domestic needs and for installation on a construction site. The cost is from 350 to 1750 rubles.
This review will allow you to choose the best gun for foam. Which is better - can be solved only empirically, but the listed models are among the most common and reliable.
How to use a gun
Working with him does not cause problems even for beginners, but there are some nuances that should be taken into account. How to use the foam gun correctly:
- Before inserting the container, it must be shaken. Instructions for use recommend making about twenty sharp movements up and down.
- The cylinder must be screwed up to the gun nozzle. Accordingly, when carrying out work, the installed cylinder must be held down by the valve.
- Before spraying the foam, it is necessary to prepare the surface. It is cleaned of dust and dirt, sprayed with water from a spray bottle. Spraying foam in hot weather is not recommended.
- To select the optimal thickness of the foam jet, it is necessary to perform test launches by pulling the trigger of the device and adjusting the end screw.
- The basic principle of filling vertical joints is the direction of movement of the gun from the bottom up. If necessary, fill a large space, perform movements in a zigzag path.
- Work begins from the ceiling. The filling volume should not exceed 30-40% of the space. This rule allows you to avoid high material consumption and trimmed dried foam.
- If, after completing work, liquid remains in the container and is supposed to be used in the future, it is impossible to remove the container, since the material will dry out.
- When the installation is complete, the cylinder is unscrewed. To prevent the liquid from drying out inside, clean the device with acetone or a special solvent in the bottle.
- According to the instructions for use, the charged device must be left in the storage tank.
How to clean the gun after work
To understand how to clean the foam gun, you need to remember the design of this product. To ensure the possibility of continuing installation with this device, it is necessary to clean the barrel from the remnants of foam.
It is best to clean the structure immediately after the work has been completed, while the material has not yet gained strength. Liquid foam is easily removed by solvents, and it is necessary to deal with the hardened material mechanically.
Using a special balloon
To clean the structure, you should remove the used container with foam and screw on a special bottle of cleaning fluid that is under pressure. This product is designed to clean the tool immediately after use.
Under the influence of pressure, the cleaning fluid penetrates the barrel, cleans the valve, trigger and removes residues through the nozzle. When the tool is completely freed from the foam masses and a clean solvent goes through the barrel, the process is complete.
Mechanical cleaning
You have to resort to this technique when cleaning with the help of special fluids does not bring success. If a considerable amount of time passes after work, the foam becomes solid and acetone cannot penetrate the mechanism.
Mechanical cleaning consists of scraping off the remaining foam from the outer surface of the gun and cleaning the barrel. You can remove dried foam from the handle and the outer surface of the barrel with a stationery knife. In the same way, you need to carefully clean the nozzle, but to penetrate more deeply into the gun barrel, you will need a thin steel wire.
The wire is screwed into the barrel of the gun, clearing the path for subsequent filling of the solvent. It is advisable to use a wire to clean the barrel along the entire length, then the final cleaning using a spray bottle will pass without problems.
In the same way, dried material residues are removed from the valve threads, preparing the surface for solvent treatment. The residues are cut with a knife and cleaned, after which the threads are completely filled with solvent and final cleaning is carried out.
It is dangerous to clean the gun with high pressure washers. The mechanism of the gun is not provided for such loads and may fail.
How to rinse a gun with dried foam
If the tool is not cleaned immediately after use, the hardened material clogs the outlet channel and further work with the gun becomes impossible. Flushing the gun for foam is carried out using solvents - water in this case will not help.
Acetone is ideal for cleaning dried material, but you can also use white spirit, solvents 646 and 647, xylene.
To remove dry residues from the barrel, you must use a syringe to pour acetone or other liquid recommended above through the cylinder mounting hole or exhaust nozzle. The solvent will soften the material and after that it will be possible to remove it under pressure.
This option is relevant in the case of foam, which has dried recently. If the material has managed to gain a strong foothold inside, you will have to disassemble the entire device and resort to mechanical cleaning of the barrel, followed by stripping with a cloth soaked in acetone.
How to disassemble the gun for polyurethane foam, you can see the video in below. This is not difficult to do, the main thing is to correctly follow the sequence of actions and carefully clean the small parts in order to avoid breakage.
The listed solvents can be used to clean any surface from foam. Dimexide has the same properties. This product can be purchased in free sale in a pharmacy. Unlike other means, it does not act destructively on the skin and is suitable for removing foam from workwear.