In order to reliably protect the metal from negative corrosion processes, a primer must be applied. This composition may have different purposes.
Varieties of primer
Primer for metal is selected depending on the external conditions that will be maintained during operation, as well as the type of surface. Thus, the primer can be designed for application to non-ferrous or ferrous metals. Among other things, this composition can be designed to convert rust. There are phosphating, passivating, insulating, inhibiting and protective mixtures.
Phosphating mixtures are two-component bases, which are made of phosphoric acid and a diluent. This mixture can be used for all types of metals. It improves grip quality.
The insulating primer is still alkyd or epoxy. It is intended to protect the surface from moisture and oxygen. Its composition includes iron minium, zinc white, as well as fillers. This composition is used most often for ferrous metals.
Metal passivating primer
It can reduce the electrochemical characteristics. Helps to slow down corrosion. If we talk about the inhibiting mixture, then it forms on the surface a new kind of material like an enamel-primer, which combines the properties of the two compositions. Inhibitors that are included in its composition can be aqueous or oil-soluble.
It is designed to work with rusty surfaces. If you need a primer for metal, then you can choose mentioned above, it consists of an alloy of magnesium with zinc, as well as lead powder. An invisible film is created on the surface after application, which is capable of protecting the metal base even in the event of scratches. This was achieved thanks to zinc particles, which are part of the primer. Quite often there is a need to treat the surface, which has already been exposed to rusting processes. There are such primers, their application is made after cleaning the surface. After the base becomes protected from moisture.
Features of selection and application
If you need a primer for metal, you first need to familiarize yourself with the criteria by which choice is made. It is important to take into account not only the type of metal, but also climatic, as well as mechanical loads. After the master should be familiar with the technology of applying the composition. Initially, the surface must be freed from the old coating, cleaned of dirt and dust, and also leveled. Among other things, it is necessary to carry out degreasing, as well as to eliminate rust.
Primer for metal rust must be applied with appropriate tools, it can be a brush, pneumatic spray or roller. If the second option is used, the work can be completed in a shorter time; however, such equipment is not always in the master's arsenal, and it is inappropriate to rent it to cover small areas. When buying materials, it is important to consider the consumption, on average, this figure varies from 120 to 140 grams per square meter. This is true for applying two layers. That is the number recommended by the manufacturer.
A moisture-proof coating is often applied over the top, in particular, for metal primers that will be exposed to frost and snow. Whatever primer would be applied, it is necessary to comply with the conditions of humidity and temperature. As for the last range, it can vary from -10 to + 25 degrees.
Features alkyd primers for metal
Alkyd paint-primer for metal can be used as an independent coating. The advantage of this composition is that it is not necessary to apply paint or enamel on top of it. Among the additional benefits are the provision of excellent anti-corrosion characteristics, as well as the possibility of applying to a surface that has been subject to rusting. Thus, this indicates that the alkyd primer acts as a converter. The mixture is able to provide reliable protection against various weather phenomena, with regard to ultraviolet radiation, as well as temperature changes.
This composition has a high hiding power. Due to the fact that among the ingredients alkyd protection is aluminum filler, the described material provides additional wear resistance.
Overview of primers and their prices
If you need to buy a primer, you should first familiarize yourself not only with prices, but also with manufacturers. For example, a primer brand LAKRA will cost 2000 rubles, this amount you have to pay for 20 kg of the mixture. It has excellent quality characteristics and is able to protect the metal from external influences. By purchasing Super with the same volume, the consumer will have to pay 1170 rubles. Covering the surface of this mixture, you protect it and prolong the life. If you need to cover the surface of a smaller area, then you can buy a mixture of the first mentioned brand in the amount of 1 kg, in this case you will have to pay in the store of building materials 120 rubles. Material brand Dufa costs 1600 rubles per 2,5 liters. As for the manufacturer HAMMERITE, it represents the sale of primer for 1150 rubles. The bank will have a volume in 0,75 liters.
The described compositions vary in purpose and operating conditions. For example, a primer for metal for a car has corresponding characteristics. However, there are universal mixtures, they are suitable for standard surfaces and for problem areas. Among the former, cast, forged, and other products can be distinguished, which have a slight roughness that improves adhesion, which is very good for priming. Among the problematic bases are copper, aluminum, galvanized metal, as well as any other materials that can give a chemical reaction on the surface and reduce adhesion.
If you buy a primer for metal GF 021, then you should be familiar with the manufacturer's recommendations. So, on the bank can be specified the time during which the composition is able to hold out on the metal. Anti-corrosion features of the composition are also important. All mentioned characteristics before purchasing materials must pay special attention. The durability of the protective coating and the lifetime of the metal itself will depend on this. You should not save on a primer mixture, it is better to purchase the product of the manufacturer, which has established itself in the market of relevant materials.