Wood filler falls into a class of products used to repair, restore and seal wood. Each type of wood filler is designed for a special use. Wood filler consistencies range from thin to thick and come in adhesive, water-based and oil-based formulations. Furniture, crown moulding, exterior wood and flooring all have different wood filler requirements. Becoming familiar with the types of wood filler will help you find the right product for a particular project.
Woodworkers use tinted paste filler to fill porous wood grains to create an ultra-smooth finish, particularly on furniture pieces. The wood should be sanded to remove imperfections, then brushed with the paste filler and allowed to dry. Oil-based paste fillers require considerably more time to dry than water-based products. Remove the excess with a rubber squeegee and burnish it by rubbing with burlap. A final coat of wax, polish or varnish completes the process.
Use an adhesive epoxy filler to bond cracked or slightly deteriorated wood, such as a doorjamb damaged by water rot. The two-part filler can be shaped to match adjacent moulding profiles. Durable epoxy filler withstands extreme temperature changes, making it suitable for both indoor and outdoor wood repairs. Epoxy wood filler does not have the strength to support structural wood repairs. Use epoxy wood filler for cosmetic applications.
To provide sheer strength when restoring wood, consider applying a wood-hardening product. Choose from two types of wood hardeners, depending on the nature of the project. Thin, single-part adhesive hardeners brush on and penetrate deep into the wood. They strengthen soft wood species and restore moderately damaged wood. Use thick two-compound resin hardeners to fill and repair structural members of wood furniture.
Many homeowners have experience with wood putty. Typically used to fill nail holes in trim moulding before painting or staining, tinted wood putty resembles modelling clay. Use nonhardening wood putty to fill small-diameter finish nail holes. This type of putty takes stain extremely well. Sand before filling holes with nonhardening putty. Choose hardening wood putty to fill larger and deeper holes. Because hard fillers do not accept stain, it is critical to fill after staining and match the putty colour to the finished wood stain.
For small projects, homemade wood filler works quite well. Take a small amount of sawdust and mix it thoroughly with wood glue until it forms a malleable, dough-like ball. Homemade filler adequately tackles small surface holes in wood furniture and moulding, although it does not provide the strength of the manufactured versions. This type of filler accepts stain when completely dry and sanded.