Varnishes and wood stain are both protective and aesthetic virtues, but each has a well-defined use.
A varnish is a more or less viscous liquid, containing a natural resin (copal, mastic, damar) or synthetic (acrylic, ketone, polyurethane) in solution or dispersion in a gas (turpentine oil). It is applied to the surface for aesthetic purposes (gloss, matte) and / or protective (dust, pollution, ultraviolet) to form a solid, colorless film. A varnish is applied directly or brush off when this aerosol. The characteristics of transparency, gloss and resistance vary according to the components of the coating, especially the resin used.
Varnishes have many properties, including:
- ease of application on any type of support (wood, metal …)
- quick drying
A stain is a product for porous materials (wood, concrete …), not generating film. We therefore oppose the varnish and paint. The main difference is due to the microporosity of the resulting film. Paint or varnish will hold a support effect, which can cause chipping outside the film.
The advantages of wood stain are to:
- preserve the appearance of the material, including veined wood surface ;
- allow traffic more or less moisture ;
- do not have scaling effect over time .. .
By cons, they can migrate into the material, or be leached more easily, according to constituents. The stains used to color (unlike varnishes, stains can be composed of solids such as pigments, for example), to protect against various attacks (parasites, effects of light, humidity). They can be made of all kinds of ingredients. It is based fats (oils), and others use resins, drying, polymerize locally, creating a sort of “flour”.