Paint Technology – Composition of Spirit Varnish In architectural finishing, which combination best represents a typical spirit varnish used for quick-drying clear coats on woodwork and furniture?

Introduction:Varnishes are categorized by the solvent and resin system. “Spirit varnish” refers to a resin dissolved in a volatile alcohol, used where rapid drying and clarity are desired. This question checks whether you can identify the canonical composition used in site and workshop practice.

Given Data / Assumptions:

• Finish: clear, quick-drying coating on wood.
• Solvent family: alcohols (ethanol/IPA/denatured spirit).
• Resin: natural resin compatible with alcohols.

Concept / Approach:

Classic spirit varnish is a solution of shellac in alcohol. It forms a clear, hard film that dries rapidly by solvent evaporation, making it useful between coats and for French-polishing-type work. No oil curing chemistry is involved, unlike oil varnishes.

Step-by-Step Solution:

Verification / Alternative check:

Trade literature and workshop manuals consistently describe spirit varnish as shellac dissolved in alcohol for quick drying clear coats.

Why Other Options Are Wrong:

Oil/wax/resin is closer to wax-oil polishes; alcohol-wax-turpentine is not standard spirit varnish; pigmented synthetic resin describes paints, not clear varnish; “none” is invalid since a correct composition exists.

Common Pitfalls:

Confusing spirit varnish with oil varnish; assuming the presence of pigments, which would make it a paint.

Final Answer:

Spirit (alcohol) solution of shellac