Does plastic primer need hardener?

Surface treatment #polystyrene, Styrofoam or white cork

In Ruta 401 we have already talked about other types of fillers, but today we are going to focus on fillers for plastics. What are their particular characteristics? Are there different types of fillers for plastics? Let’s take a look below.

Putty is a product consisting of a kind of white paste that hardens as it dries. It is often used to fix scratches, dents or flaws in different materials. Depending on the surface to be worked on, one or another specific putty will be used. The following types exist:

Within the work in the workshop we can find the need to repair bumps or dents in plastic parts, such as bumpers. The plastic is a material of a hardness and flexibility that can be very variable, but in any case it is never as rigid as metal. For this reason, for plastic filling tasks we will need a specific putty.

Before proceeding to paint the part in question it is necessary to apply the primer so that the paint adheres better to the plastic. We can find two types of primer. On the one hand there is the monocomponent, which dries by the effect of the air and is used before applying the putty or the filler; on the other hand there is the bicomponent, which incorporates a catalyst to accelerate the drying process. At Ruta 401 we recommend using TEROSON 150.


Fillers are primer or preparation paints used in vehicle refinishing with a relevant role in the quality of the final finish and in the productivity of the refinishing processes. It is a versatile product, being able to find in the market different types to adapt to different needs in terms of surface leveling, coverage, sanding, drying speed, etc. Its main purpose is to achieve a smooth and uniform surface as a base for the application of the finishing paint.

The finishing paint should not be applied directly on the sheet metal, filler putty or cataphoresis, it should be applied on primers or fillers, or on old finishing paint on the part. Due to its chemical nature and its leveling properties, the primer isolates the preparation paint from the finishing paint and provides the best base to achieve a high gloss and good stretching of the finishing paint.

The most commonly used fillers nowadays, due to their technical properties and versatility of use, are the so-called “two-component acrylic fillers”, of the same nature as single-coat enamels and finishing varnishes.

How to apply SPRAY PAINT: Essential Tips

Spray car paint is essentially the same as spray paint, albeit with some nuances. In fact, many professional body shops use some products in spray format.

In short, car spray paint is the perfect alternative when it comes to do-it-yourself car refinishing and when you do not have a professional tool or previous experience. Moreover, if you know the specific characteristics of these products and use them correctly, you can obtain really professional results…

With the help of a sprayer, we will spray degreasing solvent on the surface and we will rub with a microfiber cloth until completely eliminating any rest of dirt… In case of not having degreasing solvent, water and soap can be used, but we have to keep in mind that some substances, like the tar, are quite difficult to eliminate, reason why we will have to insist more rubbing with the cloth.

We will sand with a block applying a back and forth movement on the surface to be stripped, but without exerting too much pressure. We will try at all times that the transition between the different layers that we are reaching is smooth and staggered.

How to prepare 2K paints for automotive painting

Each two-component product has a type of hardener and the mixing ratios will depend on each manufacturer. Depending on the temperature and the haste of the repair, short, medium or long hardeners should be used.

-Short or fast: it is generally used when the temperature is very low (less than 15º), normally in winter, so that the drying time is not extended, or also when it is desired to accelerate the drying at a normal temperature (between 20º and 25º). This type of hardeners should never be used in flat surfaces, always in vertical ones, because we could have problems of brightness decrease or even boiling.