Lacquer thinners are solvents used to adjust the consistency of certain types of lacquers, paints and varnishes. These solvents have varying rates of evaporation. Common types of lacquer thinners are standard and fast thinners and lacquer retarders. When working with lacquer, it is necessary to understand the different properties of thinners. A better understanding allows greater control of the finishing process and leads to fewer problems associated with lacquer techniques.
Standard lacquer thinner is sold primarily as a cleaner and is commonly used to dissolve lacquer, inks and adhesive residues, or clean up tools and equipment after use. This type is not suitable for thinning lacquer as the formula lacks the amount of solvent needed. A high quality thinner, one with a higher percentage of dissolving agents, produces a better result when thinning lacquer. Fast lacquer thinners evaporate at an accelerated rate, which is much faster than standard ones.
Varying weather conditions can have a profound effect on drying times and can cause several problems. In warm or hot climates, these problems can arise during application of the lacquer thinners. Heat causes the thinner to dry too quickly, reducing the time needed for the lacquer self-level. Another heat related problem called dry spray occurs when the lacquer dries before reaching the surface resulting in a sandy appearance. Humid weather conditions trap moisture in the lacquer, which causes a milky appearance, called blushing.
The evaporation rates vary between standard and fast lacquer thinners. Evaporation rates for both types of thinners can be adjusted by mixing them with a lacquer retarder. The retarder has a much slower evaporation rate and can extend the working time of both thinners. Mixing lacquer retarder with standard lacquer thinner also eliminates the problems associated with hot or humid weather conditions by slowing down the evaporation rate.
As with most types of solvents, certain safety precautions should be taken when using these products. It is extremely important that the proper type respirators be worn during application of lacquer. Prolonged exposure to lacquer, thinners, and other solvents can be detrimental to one's health. These types of products are also extremely flammable and extra caution is required to avoid the danger of an explosion or fire. They should be used in well-ventilated areas away from open flame and contaminated rags should be disposed of properly.