Wood knots are dark rings in planed timber. They are caused by the small branches, which grew from the main trunk of the tree and they need to be treated before the wood is finished. Loose knots in wood are a sign of poor-quality timber and, if the knot has fallen out completely leaving a hole, this will have to be filled with wood filler before finishing.
Most knots are resinous: they continue to seep sap even after finishing. This can cause bleeding through paintwork and a dark yellow stain will appear. If you are applying clear varnish, there is no need for knotting solution, as the varnish will seal the knot. But if you want to apply a paint finish, treatment with a knotting solution is necessary.
Using Knotting Solution
On new wood that has not dried out , knotting solution is used to treat knots so they don’t seep and spoil a finished paint effect. A treated area will not accept a colour wash as well as bare wood, so apply the solution to the knot alone. A fine artist’s paintbrush is ideal for this.
Treating Pale Woods
White knotting solution, which is transparent when dry, is ideal for use on pale woods. Dab a little of the knotting solution onto a clean dry rag then rub it well into the knot. The solution will dry very quickly, leaving little or no visible marks underneath any subsequent finish.