Pohjamaalit

Pohjamaalit are primer paints used to prepare surfaces for topcoats by creating a binding layer that improves adhesion, seals pores, and neutralizes irregular absorption. They can also block stains or tannins from the substrate and help achieve a uniform finish, extending the life of the subsequent paint layers.

Primers come in several forms. Water-based primers, such as acrylic or latex, are common for walls and wood, offering low odor and easy cleanup. Oil-based or alkyd primers provide strong sealing and adhesion on porous or stained surfaces, though they require solvents and longer drying times. Shellac-based primers excel at stain blocking, including smoke and water stains. There are also primer-sealers that combine sealing and filling properties for smoother finish preparation.

Substrates commonly treated with pohjamaalit include wood, metal, drywall or plaster, concrete, and masonry. For wood, primers help block tannin bleed and improve paint holdout. For metal, primers often include rust inhibitors to prevent corrosion. For porous surfaces, sealing reduces uneven absorption and can reduce the number of finish coats needed.

Application typically involves cleaning and light sanding if necessary, followed by one or two coats of primer and a suitable drying period before applying the topcoat. Drying times depend on the product, temperature, and humidity.

Environmental considerations include the VOC content of the formulation; many modern pohjamaalit are available in low-VOC or water-based variants. The choice of primer depends on the substrate, the intended finish, and the desired durability.