Which finish is commonly used to seal pitch on wood?

Which finish is commonly used to seal pitch on wood?

• A. Shellac
• B. Varnish
• C. Oil
• D. Wax

Answer: (A)

Sealing pitch on wood needs a barrier that dries to a hard, non-oily film and blocks sap from reaching the topcoat. Shellac does exactly that: it forms a quick-drying, solid seal over resinous areas, preventing sap bleed and providing a good, stable base for subsequent finishes. It bonds well to pitchy wood and is compatible with common topcoats like lacquer or varnish, making it a reliable sealer in this scenario. For best results, use dewaxed shellac, which adheres even better to difficult, resinous surfaces. Varnish, oil, and wax don’t offer the same effective seal against pitch—varnish is more of a topcoat, oil can soften or carry resin, and wax is a soft barrier that won’t stop sap migration.

Sealing pitch on wood needs a barrier that dries to a hard, non-oily film and blocks sap from reaching the topcoat. Shellac does exactly that: it forms a quick-drying, solid seal over resinous areas, preventing sap bleed and providing a good, stable base for subsequent finishes. It bonds well to pitchy wood and is compatible with common topcoats like lacquer or varnish, making it a reliable sealer in this scenario. For best results, use dewaxed shellac, which adheres even better to difficult, resinous surfaces. Varnish, oil, and wax don’t offer the same effective seal against pitch—varnish is more of a topcoat, oil can soften or carry resin, and wax is a soft barrier that won’t stop sap migration.