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"All measures that are taken to ensure a long life of wood fall under
the definition wood preservation (timber treatment). Apart from
structural wood preservation measures, there are a number of different
(chemical) preservatives and processes (also known as timber treatment
or lumber treatment) that can extend the life of wood, timber, wood
structures or engineered wood. These generally increase the durability
and resistance from being destroyed by insects or fungus.
As proposed by Richardson, treatment of wood has been practised
for almost as long as the use of wood itself. Some accounts reach
back to the beginning of recorded history. For example the Bible in
Genesis, 6:13-14 “And God said unto Noah… make thee an ark of gopher
wood; rooms shalt thou make in the ark, and shalt pitch it within
and without with pitch.” There are also records of wood preservation
reaching back to ancient Greece during Alexander the Great’s rule,
where bridge wood was soaked in olive oil. The Romans also protected
their wood by brushing their ship hulls with tar. During the
Industrial Revolution wood preservation became a corner stone of
the wood processing industry. Inventors and scientists such as
Bethell, Boucherie, Burnett and Kyan made historic developments
in wood preservation, with the preservative solutions and processes.
Linseed oil
In recent years in Australia and New Zealand, Linseed has been
incorporated in preservative formulations as a solvent and water
repellent to 'envelope treat' timber. This involves just treating
the outer 5mm of the cross-section of a timber member with
preservative eg Permethrin 25:75, leaving the core untreated.
While not as effective as CCA or LOSP methods, envelope treatments
are significantly cheaper as they use far less preservative. Major
preservative manufacturers add a blue dye to envelope treatments.
There is an on-going promotional campaign in Australia for this type
of treatment. Linseed oil is used to preserve Wood fences, log cabins,
and wood furniture.(Such woods as Willow, Pine, oak and exc.) The
function of linseed oil as a preservative is believed to be related
to its action as a water repellent and drying agent rather than a
direct biocidal activity. A number of European companies have
developed natural-oil-only-based treatments; no synthetic preservative
such as permethrin is added. Menz Holz OHT use autoclave impregnation
with linseed, sunflower and rapeseed oil for 6 to 8 hours.
Wood treated with linseed oil is resistant to denting and scratches
and is easily repaired, but the surface is not as hard as a modern
varnish, and the wood will slowly absorb moisture if allowed to
stay wet.
Boiled linseed oil is used as a paint binder or as a wood finish on
its own. Heating the oil causes it to polymerize and oxidize,
effectively making it thicker and shortening its drying time.
Today most products labeled as "boiled linseed oil" are a combination
of raw linseed oil, petroleum-based solvent and metallic dryers. The
use of metallic dryers makes boiled linseed oil inedible. There are
some products available that contain only heat-treated linseed oil,
without exposure to oxygen. Heat treated linseed oil is thicker and
dries very slowly. This grade of linseed oil is usually labeled as
"polymerized" or "stand" oil, though some types may still be labeled
as "boiled".
From: Wikipedia.com
Efficacy of hot wax dipping
"Robinson and French (1984) indicated that some apiarists found that hot wax
dipped treatments lasted in excess of 15 years before retreatment of the material
became necessary. Some beekeepers have indicated that well-treated boxes will last
for more than 20 years before further treatment is required.
The extent of microcrystalline wax penetration was determined in trials
conducted in Australia by Robinson and French (1986)"
From "HOT WAX DIPPING OF BEEHIVE COMPONENTS
For preservation & sterilisation "
http://www.apiculture.co.za/ (Free On-line books)
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