The Best Wood Filler For Large Holes
No one wood filler is best in all situations, considering the variety of wood species on the market and all the different finishes and techniques used in woodworking projects. Matching the filler material to your particular situation is the key to patching large holes in wood.
Two-Part Epoxy
Two-part epoxy is one of the top choices for patching large holes. Moldings, sills, doorjambs, baseboard or wood trim with damage or large holes can be repaired with epoxy. The two parts are mixed like dough and can be shaped before or after it dries. Epoxies:
- Can be used to patch the biggest holes.
- Accept paint readily.
- Won't accept stain.
- Can be shaped with tools when wet or dry.
- Have strength to handle structural repairs.
- Are available in exterior formulas that stay flexible.
- Typically require 24 hours to dry.
Polyester Paste
Polyester filler is used to repair holes in car bodies. It's also used for bigger holes in wood. It works much the same way as two-part epoxy, but the application is different. A wood hardener is applied with a brush to strengthen the wood, followed by a resin. This filler:
- Tends to sag.
- Typically requires at least two coats.
- Begins to harden in 15 minutes.
- Is best for rotten, deteriorated wood.
- Requires a hardener that is somewhat toxic.
- Won't accept stain.
- Sands and accepts paint readily.
Spackling Paste
Standard spackling paste is one of the top choices to patch holes in interior wood such as jambs, baseboard or trim of any type. Made with gypsum plaster, it's also used to patch drywall. Spackling paste:
- Tends to shrink.
- May pop out when wood expands and contracts.
- Dries hard.
- Sands evenly.
- Accepts paint readily.
- Doesn't stain well.
- Is not suitable for the largest holes.
- Typically requires more than one application.
Cellulose Wood Putty
Cellulose fillers are mostly for filling holes in woodworking projects like cabinets, mantels, trim or projects that you plan on finishing with stain and a topcoat. Cellulose filler is made with real wood. The putty:
- Won't shrink
- Sands flat and even.
- Accepts stain or paint just like real wood.
- Dries hard.
- Is not suitable for holes larger than about 3/8-inch.
Caulk With Silicone
Acrylic caulk with silicone is great for medium-sized holes in exterior wood. This filler:
- Is moisture-resistant.
- Stays flexible to move with the wood.
- Adheres quickly.
- Is available in colors to match wood or paint.
- Can be applied easily from a tube.
Old School
Woodworkers have been using sawdust and white wood glue together for many years. It's a simple procedure: mix equal parts white wood glue with sawdust until a paste forms. Trowel it into almost any hole up to about 3/8-inch. The mixture:
- Matches wood when the same species of sawdust is used.
- Shrinks.
- May require several applications.
- Can dry white if too much glue is used.
- Sands easily.
- Won't stain but accepts paint.
- Dries fast, requiring fast application.