Varnishing is the perfect finish for outdoor projects. When selecting the varnish, ensure that the one you pick is suitable for outdoor use, even if the project in question is actually for a bathroom or kitchen. This is important as it is necessary to choose a waterproof varnish for most projects. Marine-type varnish is usually the best choice as if it is good enough for a boat, it will certainly suffice for the more mundane outdoor projects.
Before applying the varnish, use white spirit to clean to wooden surfaces. Use this sparingly on a clean cloth, and then wait 30 minutes to allow the wood to dry.
The trick with varnishing is to apply very thin coats, and many of them. If the varnish is applied too thickly, it will not dry correctly and will look odd. Also, make sure that the workshop is not too cold (or hot) for the application of the varnish as this will also ruin a perfectly good project. To find the correct temperature range, consult the instructions on the side of the varnish tin.
Before applying a second or third layer of varnish (we recommend at least three layers), lightly sand the previous layer of varnish. For this you should use very fine sandpaper as the idea is to roughen the previous layer, not remove it completely. The reason for doing this is to create a surface that allows the new layer of varnish to bond correctly -- smooth, gloss surfaces will not bond too well.