Like any primer, GF-021 is designed to protect metal from corrosion. It is suitable for the first treatment of metal surfaces. However, wood, plywood, chipboard and MDF sheets, and even plastic can be covered with this primer. GF 021 lays on these materials in an even and uniform layer.
According to the norms, the GF 021 primer should be red-brown (shades of colors are not subject to standardization), but manufacturers also produce a primer of a different color. In particular, white, light gray, gray, black. Such coverage is made according to technical specifications, which each company establishes independently. Therefore, in order not to receive a not very good product in exchange for high-quality paint, try to purchase certified products from well-known manufacturers.
Primer is a good basis for almost any paint coating. However, before applying it, it is necessary for GF-021 to dry completely, otherwise the “clear coating can be “welded”. The consumption is 90-110 g/m2. The dried GF 021 can be diluted with white spirit. You can use a spray gun, brushes to apply the primer or rollers. Metal surfaces must be prepared before application. For this, rust must be removed, dust removed and degreased with a solvent. If a wooden surface needs to be primed, it must first be dried. When opening containers with primer on a dense film may appear on the surface, which must be removed.
Since GF-021 has a rather sharp smell, work with it should be carried out in well-ventilated rooms or outdoors at a temperature not lower than 5 ° С.
After application and drying, the surface becomes matte. If the surface needs to be strengthened for applying a further coating, then you can use sandpaper with P600 or P800 grit. After this treatment, the primed surface becomes very smooth, so the subsequent layers of any paint coatings fit very well.
Despite its low price, GF-021 is no worse than foreign analogues, which is why it is strictly used.
However, there are also disadvantages. Such a primer cannot be used as a fixative for bulk materials, as it covers the surface only from above and does not penetrate deep layers. Therefore, if the initial coating is not strong, then you need to use a penetrating soil.
Another disadvantage of GF 021 is the long drying time. Full formation of quality properties at a temperature of (20±2)°C and relative humidity (65±5)% for 4 days.
The service life of the primary material made by any manufacturer is no more than six months, during which time the container with the primer should be kept tightly closed and not exposed to sunlight.