Application of automotive primers
Primers can be applied to vehicle surfaces in several ways: by dipping, brushing, electrodeposition, spraying and electrospraying. Some methods are used exclusively in series production of vehicles (e.g. dipping). This is due to the high consumption of paint material. It is impractical to fill a tank with a huge capacity to apply paint to one or two cars. Other methods can only be used for partial repair of the bodywork, such as applying paint material with a brush.
In good car repair shops, more than one type of primer is applied to the surface of the car. Initially, the metal is coated with some kind of phosphating or acid primer, which provides good adhesion. The composition is well distributed over the surface and does not require subsequent sanding and application of several layers. The primary primer is applied to a well prepared, cleaned and degreased metal surface. You must be very careful when working with acidic or phosphating automotive primers, as you can get severe chemical poisoning if the room is not adequately ventilated.
After the primary primer coat, a secondary coat is laid. This is often a hard or soft two-part system (sandable or non-sandable). Secondary automotive primer is applied in two or three layers and well hides minor surface imperfections (penetrates into pores, fills small indentations and irregularities). Layers are applied at intervals of 5 to 10 minutes. Now to save time, most auto service stations use automotive primers that do not need to grind, but it is necessary to have a master with a high level of training (so you do not have to redo the work because of mistakes). Secondary priming layer is laid in the case when it is necessary to hide visible defects in the surface.
If the base metal is perfectly smooth surface layer, you can as a secondary priming layer immediately apply uncut composition, which has a glossy surface. It dries quickly enough.
Then, after at least 15-20 minutes, the final coat of paint is applied.
Choosing the automobile primer it is better to give preference to the reliable companies-manufacturers. It is better to restore the car only once but very well than to do all the work over again. When choosing a primer always check its expiration date, because the expired composition will not achieve the desired effect.