As the cost of labour and materials continues to increase, it is important for woodwork to have a long, serviceable life. The cost of labour needed to repair rotten boxes etc., may be higher than the cost of treating and building new equipment. Most of the timber used in the beekeeping industry is from plantations of hoop pine (Araucaria cunninghamii). This timber does not seem to have the durability of timber from large, naturally occurring trees.
Timber rots quickly in hot, wet climates. Therefore it is essential to treat timber to avoid unnecessary waste.
Solvents and additives
Choice of solvent is influenced by workplace, health and safety legislation. Mineral turps is recommended.
Pale boiled linseed oil is occasionally added to the mixture (up to 15 %) to help reduce cracking in drier areas. Reduce the volume of solvent by the volume of linseed oil added.
Make sure you to know the strength of the copper napthenate, because only 10 % of it is available copper, for example, the maximum strength on the market is 50 % copper napthenate or 5 % copper.
There are two treatment methods.
Soak and wrap
The timber is soaked in 1.25 % copper solution for one hour, tightly wrapped in plastic for three days and then aired for 10-20 days, depending on temperature (penetration is faster at higher temperatures).
This is the most commonly used technique. Timber is soaked in a 1 % copper solution for 12-24 hours, drained, and aired for between five and 60 days, depending on the air temperature.
It is essential to air the treated timber so that the paint will adhere. It is recommended to air the timber using either of two methods:
- assemble the equipment and allow it to dry
- stack the timber parts using pieces of wire or timber of the same thickness to separate the hive timbers.
Once the equipment has been assembled and nails punched etc., dip the woodwork again to ensure that cracks and nail holes are covered with preservative.
Joints can be painted before assembly, with the paint acting as a glue and sealer (particularly if oil-based undercoats are used). Paint both outside and inside the box with a coat of suitable primer or undercoat. Putty all cracks, punch holes and other defects using a filler recommended for external use.
Oil or water-based paints may be used for finish coats, depending on the manufacturer's recommendations. Remember that white is the coolest colour in summer and warmest in winter, and that enamel paint has a harder surface than acrylic. Acrylic paint blocks up sanding discs or paper but can be re-coated easily and has a long life. Brushes can be washed out in water. Aluminium paint has a degree of fire resistance compared with other paints. It lasts well, but is unsuitable for honey supers and lids during summer months in hot western areas.
Timber can be preserved by soaking for 12 hours in either of the following mixtures:
- 5 L 5 % copper (50 % copper napthenate) + 20 L solvent
- 12.5 L 2 % copper (20 % copper napthenate) + 12.5 L solvent.