Surface Preparation
The Sanding Schedule
Never skip grits. Each grit removes scratches left by the previous one. Skipping from 80 to 220 leaves 80-grit scratches that are invisible until the finish magnifies them. Standard progression: 80 (remove mill marks) → 120 → 150 → 180 → 220 (ready for oil/wax) → 280–320 (ready for lacquer and polyurethane). Sand with the grain on the final two grits.
The Card Scraper
A card scraper is a thin piece of spring steel with a turned burr on its edge. Used correctly, it shears wood fibres cleanly rather than abrading them — producing a surface that sanding cannot match on difficult figured grain. The burr is turned with a burnisher pressed firmly along the edge at a slight angle.
Raising the Grain
Water-based finishes raise wood grain on first application, standing up loose fibres. Prevent this by raising the grain deliberately before finishing: wipe the surface with a damp cloth, let it dry completely, then knock back the raised fibres with 220-grit paper. The subsequent water-based coat will not raise grain again.
Colouring and Ebonizing
Dyes vs Stains
Pigment stains deposit opaque colour particles in pores and scratches — they muddy the figure and make cheap wood look dirty. Aniline dyes dissolve into the wood fibres themselves — they deepen colour while enhancing figure and chatoyance. For fine furniture: always use a dye. Pigment stains belong on utility furniture and floors.
Chemical Ebonizing
Oak and walnut are rich in tannins. Iron acetate (steel wool dissolved in vinegar over several days) reacts with tannins to produce pitch-black iron tannate — a permanent colour change from within the fibres. Unlike black stain, which sits on the surface, ebonized wood looks black all the way through. The reaction is permanent and archival.
Topcoats
Penetrating Oils & Waxes
Boiled linseed oil, tung oil, and hard-wax oils (Rubio Monocoat, Osmo) penetrate wood fibres rather than forming a surface film. Easy to apply and repair, natural feel, beautiful grain enhancement. Lower protection than film finishes — not suitable for dining tables under heavy use.
Film Finishes
Polyurethane, lacquer, and varnish form a hard film over the surface. Polyurethane is the most durable for dining tables. Lacquer dries fast (re-coat in 30 minutes) and buffs to high gloss but is brittle. Varnish (exterior grade) is the most UV-resistant. Apply in thin coats — five thin coats outperform two thick ones in every measure.
French Polishing
French polishing applies shellac dissolved in methylated spirits using a pad of wool inside cloth in circular and figure-8 motions. Hundreds of micro-thin coats build a depth of finish unmatched by any other method — a mirror-deep gloss with a warmth that no film finish can replicate. Requires high humidity, careful pad charging, and infinite patience.
The Finishing Library
Mill 10 identical blocks from the same plank of figured wood. Apply a different finishing schedule to each, labelled on the back: raw oil, wax, shellac wash coat, dye + oil, dye + polyurethane, ebonizing, lacquer, French polish, waterborne poly, and paint.
Success criteria: All 10 blocks from the same plank for fair comparison. Each finish correctly applied with no drips, bubbles, or contamination. French polish block has depth clearly distinguishable from the lacquer block. Labels are permanent.
Phase 5 Practice Exercises
12 exercises to build skill through direct application.
Card Scraper Prep
Prepare a card scraper: file the edge flat, burnish the burr. Test on figured grain.
- File technique
- Burnisher angle
- Burr quality testing
Full Sanding Progression
Sand one board through: 80, 120, 150, 180, 220. Examine under raking light at each stage.
- Grit sequencing
- Scratch pattern reading
- Raking light inspection
Raise the Grain
Apply water to a board, let dry, sand back 220-grit. Repeat until no grain raises on the final coat.
- Grain raise understanding
- Knock-back technique
- Water-based prep discipline
Dye Application
Apply aniline dye to two boards — one sanded, one scraped. Compare figure clarity.
- Dye application technique
- Wipe-off timing
- Surface prep effect on result
Ebonize Oak or Walnut
Make iron acetate. Apply to oak or walnut. Observe the reaction. Re-apply for deeper black.
- Iron acetate preparation
- Tannin reaction
- Application layering
Hard Wax Oil
Apply Rubio Monocoat or Osmo to two test panels. Compare sheen and feel after 24 hours.
- Single-coat technique
- Wipe-off timing
- Cure assessment
Polyurethane Practice
Apply three coats of oil-based polyurethane. Assess runs, brush marks, and inter-coat adhesion.
- Brush loading
- Thin coat discipline
- Sanding between coats
Lacquer Test
Apply pre-catalysed lacquer in four thin coats. Compare build and clarity versus polyurethane.
- Spray or brush lacquer
- Re-coat window
- Clarity comparison
Shellac Wash Coat
Apply a 1lb cut shellac as a sealer before a waterborne topcoat. Assess grain raise.
- Shellac concentration
- Wash coat technique
- Sealer function
French Polish Attempt
Attempt French polishing on a small panel using a rubber pad. Assess depth after 10 passes.
- Pad construction
- Charging technique
- Progressive build
Compatibility Test
Test your chosen stain and topcoat on scrap. Some combinations wrinkle or lift.
- Chemical compatibility
- Test before committing
- Finish system planning
Repair Practice
Damage a finished surface deliberately. Attempt to repair it invisibly using the correct technique.
- Finish repair approach
- Blend-in technique
- Damage assessment