Finishing, Surface Treatment and Adhesives
Surface preparation
Plane or scrape, then sand in grit order 80 → 120 → 180, raising the grain with a damp cloth before the final pass, then dust off. Fill open pores with paste filler, seal with sanding sealer, cut back lightly. Surface faults under a finish show twice as badly as on bare wood.
Stains and finishes
Water stain (cheap, raises grain), oil stain (slow, even), spirit stain (fast, non-grain-raising). French polish - shellac dissolved in methylated spirit, applied with a rubber in thin coats, best on close-grained wood and traditional furniture. Also linseed or tung oil (in-the-wood), wax, polyurethane and spar varnish, nitrocellulose lacquer, catalysed PU and water-based finishes. Rub down between coats with 320–400 grit; dust control matters more than coat thickness.
Adhesives
PVA - interior, clamp 30–60 minutes, needs close joints. Cross-linked PVA (D3) - semi-waterproof. Urea formaldehyde - interior plywood and particleboard. Phenol resorcinol and PF - waterproof, exterior. Epoxy - gap-filling, good on oily woods. Animal glue - reversible, used in instruments. Contact adhesive - laminates. Joint fit, 8–12% MC, shop temperature above 10 °C, correct pressure and open time decide success.
Worked example
A teak table in humid Assam: wipe the oily faces with solvent, glue the frame with epoxy or resorcinol, and finish with catalysed PU rather than French polish, which water-spots. Cramp with sash cramps and check the diagonals.
Traps
Sanding sealer over-sanded; PVA used outdoors; too much glue so the joint starves; finishing over dust; spirit stain bleeding through a water-based topcoat; shellac applied over silicone contamination.