Pore Filler — Lutherie Encyclopedia

Pore FillerType: toolA paste or liquid product applied to open-pored tonewoods to fill grain pores before finishing for a smooth, glass-like surface.## Description Pore filler is a finishing product designed to fill the open pores in ring-porous and semi-ring-porous woods such as rosewood, mahogany, koa, and walnut. It is available as an oil-based paste, water-based paste, or epoxy-based liquid. The filler is worked into the wood grain, allowed to partially set, then scraped or wiped off the surface, leaving the pores filled while the surrounding wood surface remains clean. This creates a level surface for subsequent finish coats. ## Use in Lutherie Many tonewoods used for guitar backs, sides, and necks have open pores that, if not filled, create a textured finish surface regardless of how many coats of lacquer or polyurethane are applied. Pore filling is typically done after sanding the bare wood to final smoothness and before applying any sealer or finish coats. On rosewood and mahogany, pore filling can save many hours of extra finish coats that would otherwise be needed to fill the pores with finish material alone. Some luthiers prefer to leave pores unfilled for a more natural, open-pore aesthetic. ## Selection Guide Timbermate, Aqua Coat, and Z-Poxy are popular choices among luthiers. Water-based fillers are easier to clean up and less toxic. Epoxy-based fillers (such as Z-Poxy thinned with alcohol) offer the most durable fill and are popular for rosewood. Oil-based fillers like Behlen Pore-O-Pac are traditional but slower to dry. Choose a filler color that matches or is slightly darker than the wood. Budget 10 to…