Conversion finishes are some of the most protective of all wood finishes. They cure quickly and form a tough, protective coat that has excellent resistance to heat, wear, water, and solvents. Unfortunately, they also involve toxic solvents and produce air-polluting fumes. Finishes in this category include catalyzed lacquer, conversion varnish, epoxy finish, two-component polyurethane, polyester, and UV curing finishes. Of these, pre- and post-catalyzed lacquers as well as conversion varnishes are the most popular. Conversion finishes are most often used for institutional furniture, such as furniture for schools, laboratories, and offices.
Pros
- Excellent heat, wear, water, water-vapor, solvent, acid and alkali resistance.
- Very fast curing (seconds for UV-curing finishes!)
- Easy to thin and spray.
Cons
- Highly toxic solvent and formaldehyde fumes. Also flammable and air-polluting.
- Very difficult to strip or repair.
- Poor rubbing properties and so-so clarity.
Brand Names
Gemini White Conversion Varnish
General Finishes Conversion Varnish
Sher-Wood Catalyzed Lacquer
Sher-Wood Conversion Varnish
Valspar Valtec Pre-Catalyzed Lacquer
Valspar Global Resistovar Conversion Varnish
Valspar DURASPEED Modified Conversion Varnish
Application
Conversion finishes are typically sprayed on in a manner similar to that of nitrocellulose lacquer. The main differences are that the film builds quicker and the time between coats is shorter. Some conversion finishes like conversion varnish cure more slowly so be careful of runs and sags and allow more time between successive coats. Also note that conversion finishes don’t adhere well to shellac or other common sanding sealers.
