Plastic wood filler is a type of putty that is formulated with wood fibres. It moulds easily to mimic the texture of wood, and both water-based and solvent-based formulas are available. Most plastic wood fillers are one-step products that are applied straight out of the can or tube.
High-quality plastic wood filler from a reliable manufacturer is convenient and easy-to-use for filling small cracks and gouges in wood. It can be used before staining, as well as for repairing damage to furniture that has already been stained and finished.
Choose the right colour plastic wood filler for the job. Match the colour of the filler to the colour of the raw or finished wood that is being repaired. If a proper match is not available, it is best to use the lightest colour so that it can be easily stained once it dries.
Make sure the wood is clean and dry. If the wood is to be stained, stain it and allow it to dry before using the filler. Do not varnish, shellac or otherwise glaze recently stained wood that is to be repaired with plastic wood filler.
Stir any canned filler product that show signs of separation, such as a layer of liquid above the putty. Solvent-based fillers can be thinned with common paint thinner if they have become too thick in storage, and water can be used to thin water-based fillers.
Use a putty knife or gloved finger to press the filler into the hole or depression. Build the fill slightly higher than surface level to facilitate sanding. Remove excess filler with a putty knife so as not to allow the filler to remain in contact with the surrounding area.
Let the filler dry, and then sand and stain as necessary. Drying time can vary between one and two hours, with solvent-based fillers usually drying more quickly than water-based formulas. Remember to clean all tools before the filler hardens; use white spirit for solvent-based fillers and water for water-based fillers.
Most major manufacturers of plastic wood filler produce colours of filler that match the most common raw woods and wood stain colours. Pine, mahogany, and walnut colour wood fillers are among the most widely available. Not all wood fillers can be used outdoors. Make sure to select an indoor/outdoor wood filler for outdoor surfaces.
Do not work with plastic wood fillers without wearing gloves. These products are known to irritate the skin.