The main problem with wood is that it is natural. We have all become so accustomed to man made products designed to perform exactly as we wish and always in the same way, it’s easy to forget that wood is a living material.As such therefore, the source of the difficulty lies in that fact that timber, even after it’s been cut down, will keep on moving as it adapts to the surrounding atmospheric conditions. On top of this constant movement, we have natural defects that can cause us problems when finishing and fitting. Below I will highlight some of the main problems and what can be done to prevent or prolong the life of the timber around your home.
KnotsA knot is where a branch was connected to the tree. There are two different types of knot, a live knot and a dead knot. A live knot is usually lighter in colour and will generally never fall out. A dead knot is darker and can fall out leaving a hole which can have an effect on the strength of timber. Knots are more common in softwoods like pine. These coniferous trees have many branches growing along the length of the trunk, creating knots.
Knots can enhance the appearance of a usually plain timber and when varnished or stained can look quite appealing. The main problem with knots is sap seeping out of them.Knots can enhance the appearance of a usually plain timber and when varnished or stained can look quite appealing. The main problem with knots is sap seeping out of them. If you paint, stain or varnish over a knot without first treating it, you could end up with a stain appearing through your paint job and looking very unsightly. This is more apparent and common when painting over knots with a white paint. You often end up with a yellow stain spoiling your lovely new paint job. The remedy is to first apply a knotting solution. This is a natural resin in solution that seals knots and prevents the sap from seeping out. It is usually supplied in a small can with a brush attached to the lid and you simply paint on over the knot. It is available in most DIY stores and costs approx. €7-9. This will prevent that unsightly stain coming through.
Another way of dealing with a large knot is to remove it with a router, a drill or carefully chisel it out and set a piece in. This is normally done on high quality furniture or where the strength of the timber is jeopardised. The photo above shows an example.