Wood fillers fix mistakes, fill holes and cover imperfections in a piece of wood or woodworking project. Certain wood fillers work better in a given situation than others and appear different on separate species of wood. Some wood fillers may also act as a glue or adhesive so that joints appear seamless within a woodworking project.
Epoxy is a very hard, durable wood filler that can be used to fill any sized hole from large and gaping to tiny and minuscule. Epoxy is commonly used to fill large spaces since it doesn’t react to heat and cold by expanding and contracting like other wood fillers. It generally comes in two parts, in a resin and an adhesive, that mix together to form a paste. Premixed wood epoxy paste is also available. Epoxy molds, shapes and stretches easily when wet, making it ideal to build up, repair or replace extremely damaged or missing areas of wood or woodworking projects. This type of wood filler doesn’t move, shift or degrade within the hole once hardened, so it doesn’t risk the hole having to be patched again at a later date. Because of its durability and strength, mistakes in patching with epoxy are not easily resolved. Epoxy may dry clear, white or in a wood tone depending on the brand and specific type used.
Putty comes in different colors and shades to match the species of wood or stain used. Colors may not match perfectly, but closely resemble the wood or stain so that no extra stain or coloring is required to cover the patch. If a premixed color doesn’t match the damaged wood, mixing two or more colors together may achieve the desired match. Wood putty performs best on small- to medium-sized holes, and shouldn’t be used to repair larger holes as it is not as durable as other types of wood filler. An oil-based wood putty is available for filling small holes such as nail holes and joints for a finished look, and remains flexible after drying.
For small holes or imperfections in a woodworking project, a quick wood filler is a clear drying wood glue mixed with some fine sawdust. This method creates a patch that closely or completely resembles the original wood. Glue and sawdust should only be used to patch very small holes or damages, as it will not hold up structurally or look as good on larger holes. Sawdust should be made from the existing wood if possible. If sawdust is unavailable, clear wood glue or super glue creates a temporary patch that will stop the hole from growing until a more permanent wood filler can be applied.