Situations where the lake is not to blame for the poor quality of the finish

Why doesn't the finish come out even though I use good finishing products? Because there are several aspects that need to be considered to achieve a quality finish. For example, conditions in the working environment are very important. It is not enough to use only very good materials and to respect the application technologies. We must also have the right working conditions to achieve quality finishes.

Dust, the enemy of the glossy finish

Finishing should be done in specially designed areas away from dust sources. Praful in the production and grinding areas is the enemy of finishing.

According to the working technologies, after application, film-forming materials need drying time before they become a film. This drying time has several stages: powder drying, impression drying, sanding drying, drying for packaging.

The powder drying time is the time during which the film dries superficially. If there is dust in the area during this time, the dust will settle and become embedded in the film. The higher the gloss of the varnish, the more visible the impurities in the film. The dust embedded in the final varnish layer causes the tint of the film to change and become rough.

Influence of temperature on film quality

Temperature is another factor to take into account for a quality finish. Product data sheets recommend that the temperature in the finishing area should be 18-20°C. Slight variations from these temperatures are acceptable, but it is very difficult to achieve a perfect finish if, for example, working at 8-10°C in winter or 38-40°C in summer. If the temperature is very low, the viscosity of the varnish will increase. When applying, the varnish will be thinned with a higher percentage of solvent. When it dries, there will be less material left on the board, so in the end a thinner film will result. The lower temperature also leads to less adhesion to the substrate. If the temperature is high, the thinner will evaporate very quickly, the film will be rough, with air bubbles included, or it will look like orange peel.

It is good to keep the ambient temperature, the temperature of the finishing materials and the temperature of the wood substrate at the same values or within a narrow range during the work.

Ventilation in the workspace

Other factors that influence the quality of the finish are ventilation in the finishing area and exhaustion. Ventilation is especially important when using water-based products. Lack of it leads to increased drying time and sometimes to a milky appearance of the film due to the impossibility of total evaporation of water. Exhaustion ensures that work is carried out in a clean and safe environment, which certainly has the effect of improving the quality of the finish.

Polishing, necessary to reach a very high gloss level

The influence of the working environment is best seen in the gloss finish. High gloss or mirror finishis the one made with varnish with a gloss level above 95. Often, in order to achieve the desired gloss, further polishing is necessary (polishing) of the lacquer film. This is done using abrasive pastes. Polishing removes dust or other impurities trapped in the film, small dents, scratches or orange peel. This ensures perfect light reflection and the highest quality gloss. Polishing can sometimes increase the gloss dramatically.

Related to this operation, I learned from the technical director of a musical instrument factory that he was able to raise the gloss of a guitar from 65-68 to 95 just by polishing.

It's great to use quality products, but don't expect them to work wonders. They are only part of the finishing process. For a quality finish, attention must also be paid to the working environment, the plant and machinery used and the way people do their jobs.

I'd be happy if you could tell me what "unexplained" problems you had during finishing. Maybe, together, we can find the explanations.