Polyurethane varnish is easy to apply; you simply brush it on, taking care to work with the grain of the wood. Follow the manufacturer’s instructions as to the number of coats you should apply and the time allowed between each coat — at least 12 hours. You should sand down the surface lightly with flour-grade glass paper between coats to provide a key for the next coat, and remove any dust that’s accumulated during application with a damp cloth.

As with paints, it’s advisable to stir the contents of any can of varnish that’s been stored for a while. This ensures an even distribution of the solvents so that the varnish dries evenly when it is applied. Although the varnish will be touch-dry in about 4 hours, it may take as long as 7 days before the surface reaches full hardness — so avoid standing anything on the newly-decorated surface for a week or so.

1. After you’ve made sure the surface is clean and dry, use a clean cloth pad to apply the first coat. Rub it well into the wood along the grain.

2. Leave the first coat to dry arid then brush on the next coat. Make sure the brush is really clean, with no paint particles or loose bristles to mar the finish.

3. When brushing, it is important to work with the grain and brush out fully. On a narrow surface like a shelf upright, first apply the varnish in one stroke.

4. Then work the brush out towards the edges of the upright, working first to one edge and then to the other, using gentle but firm strokes.

5. To complete coating the upright, again move the brush in one upward stroke. This technique will ensure that there are no ugly ‘runs’ at the edges.

6. Leave each coat to dry for the recommended time (approx 12 hours) before re-coating. Rub down between coats with flour-grade glass paper.