Wood Filler

Match the filler to the substrate and use: water-based or acrylic fillers for interior, sanding, and painting; epoxy or polyurethane fillers for structural repairs, exterior use, or gaps needing strong adhesion; and stainable/wood-specific formulas when color-matching is important

Estimate based on the total volume of gaps or holes to fill; small touch-ups use tubes or small tubs, larger repairs require multi-ounce or two-part epoxy kits. For many small defects, calculate area and average depth to convert to volume and choose a container slightly larger than that volume

Cure times vary: water- or solvent-based fillers often set in 30 minutes to a few hours and fully cure within 24 hours, while two-part epoxies can cure in 1–24 hours depending on formulation. Only sand or apply finish after the filler is fully cured to avoid gumminess or poor adhesion

Many fillers are paintable; only some are stainable—epoxies and pigmented wood fillers accept stain better. Sand smooth, clean dust, and use a stainable filler or apply a stain-sealing primer/coating for consistent color before finishing

Use gloves and work in a ventilated area; follow label warnings for flammable solvents or isocyanates in some epoxies. Store unopened containers in a cool, dry place per manufacturer guidelines and use opened tubs within recommended time to avoid skinning or contamination

Two-part epoxies offer superior strength, gap-filling, and moisture resistance but require mixing, quicker working time, and more skill; premixed or single-component fillers are easier to apply, more forgiving for small repairs, and often easier to sand

Yes; single-component water-based or solvent-based fillers are typically lower-cost and suitable for cosmetic repairs and small holes, while investing in a midrange epoxy or polyurethane product is preferable for structural or exterior work where durability matters