Demand For Coatings

The product manager for paints and glazes at Caparol provides information about the requirements for coating work.

The trend for light-colored lacquer and glaze surfaces on wooden components indoors continues. The requirements for the coating work can be very different. The Malerblatt interview with Peter P. Jaeger, who works as product manager for paints and varnishes at Caparol, provides information on what needs to be considered.

What is covered by indoor wood coatings?

The spectrum is diverse. Wooden doors, ceilings, wall coverings or wooden floors should shine in new splendor. In addition to raw wooden substrates, the painter finds industrially manufactured wooden surfaces or a wide variety of old coatings. With a little nitro thinner on the cloth and rubbing it in, you can determine whether it is a dispersion or alkyd resin varnish. The dispersion paint swells and becomes soft, the alkyd resin paint does not. You have to know that, because an alkyd resin varnish cannot be used to coat dispersion varnishes.

Lacquered wooden doors, ceilings, wall cladding and baseboards.

What types of coatings are possible?

First you decide on the color and look. Then the question has to be answered whether the coating is glazed or opaque. Afterwards, after the substrate check, it must be determined whether work is carried out with solvent-based or water-dilutable materials. Before painting, grease, oil and dirt must be removed from the surface with special cleaners. It should be noted that grinding cannot replace proper cleaning. Conversely, preparation of the surface always requires grinding work. Various materials are available to the craftsman here (fleece or classic sandpaper). To ensure that the new coating adheres well, a completely matt sanding is particularly important. Damage and cracks must be removed and processed with the Capadur Repair System, for example, according to the desired surface. Primers and primer as well as airless filler can be used as required.

Welche Produkte werden bevorzugt verwendet, und worauf ist zu achten?

Alkydharzlacke kommen in Innenräumen nach wie vor zum Einsatz. Viele Handwerker haben damit positive Erfahrungen bei der Verarbeitung gemacht. Denn Alkydharzlacke reagieren reversibel, wodurch Ansätze besser vermieden werden. Mitunter sind die Objektbedingungen und Voraussetzungen nicht gegeben, einen Dispersionslack aufzutragen. Dann muss mit Alkydharz-Produkten gearbeitet werden. Auch wenn sie lösemittelarm und aromatenfrei sind, lassen sich hierbei Geruchsbildungen nicht vollständig vermeiden, was sensible Menschen nach Lackierarbeiten bisweilen beanstanden.

Everyone knows that paint smells

Yes, when the paint dries, the solvent evaporates first, and its smell disappears within a short time, depending on the ventilation situation. Then you smell the vegetable oil drying of the binder, which is responsible for the typical oil paint smell. This property is typical for alkyd resin paints and independent of the manufacturer - so it does not represent a product defect.

What can you do if alkyd resin products have been coated and the smell is annoying?

Then you can counteract with air purifiers. Caparol recently tested several such cleaners. In addition to the subjective perception of the smell, the practice-oriented handling such as transport, usability and noise were also included. The devices can already be used when carrying out the painting work. According to the results, it takes an average of ten to 14 days to set up or start up the air purifiers. The craftsman can inquire, for example, which devices have been tested via the Caparol field service. The devices can be rented, leased or bought.

How are water-thinnable products processed in contrast to alkyd resin paints?

The craftsman has a larger selection of special brushes and rollers than ever before for processing water-thinnable products. Caparol's low-fog spray technology (NAST) has also proven its worth. This means that doors, frames, banisters and much more can be painted efficiently. Anywhere where spraying is not possible due to the area and the local conditions, this enables economical work. With the water-thinnable NAST products and the NAST spray technology, the craftsman has the best opportunities to create outstandingly uniform paint surfaces with little effort. Even with small areas (e.g. a door).

Paint economically with NAST spray technology.

Can you coat with water-thinnable products on wooden substrates and discolouration rich in ingredients?

With white and very light coatings on wooden surfaces, yellow and brown coloring can occur in places, especially when using water-thinnable lacquers and wood colors. These discolorations are wood components such as resins, tannins or lignin components, which are among the natural wood components. In conifers, oak and some tropical woods in particular, these ingredients can be present in considerable quantities. They are usually integrated when using special barrier colors. Occasionally it happens that the ingredients also penetrate the molecular structure of very densely cross-linking lacquers. Branches, in particular, act like drainages that channel the transport of the ingredients under the coating surface. The ingredients occur here in a particularly high concentration, which leads to high penetration pressure. To counteract this, there are special products such as Capalac Aqua Multiprimer and Capacryl Holz-IsoGrund. After each coating with these products, ensure that there is a sufficient drying time before painting, so that the wood contents are adequately incorporated in the film. The waiting time is twelve to 24 hours.so that the wood constituents are sufficiently incorporated in the film. The waiting time is twelve to 24 hours.so that the wood constituents are sufficiently incorporated in the film. The waiting time is twelve to 24 hours.

Caparol has recently defined classifications of the areas of application in the technical information. What does that mean for indoor painting?

Depending on the location and type of use, both exterior and interior surfaces are subject to a wide variety of climatic loads, which must be taken into account when selecting suitable coating materials and systems. A blanket claim between indoor and outdoor use is not always precise enough to determine the suitability of the products for the respective area of application. Depending on the use, stresses caused by temperature, water vapor and condensation can vary in intensity, particularly indoors. While the indoor climate in a conventional living room, for example, is consistently constant and uncritical, it can look very different in a production hall or commercial kitchen. In both cases, however, it is an interior. The new assignment of Caparol enables the craftsman to make a safe product selection for a wide variety of conditions, even when painting.

Photos: Caparol Source: Malerblatt 08/2014