Paraffin wax dipping is used extensively by beekeepers in New Zealand for
both preservative treatment and to treat equipment infected with AFB.
 
Earliest reference I have (as a preservative) goes back to 1939:
 
Robinson, D.S.  1939.  Paraffin wax for preserving hive parts. NZ Journal
of Agriculture 58:79.
 
It refers to the practice having been 'tried out for a number of years'.
Method has changed very little in the 50 years
since!
 
A follow up article appeared a few years later:
 
Line, S.  1953.  Preserving hive parts with paraffin wax 87: 249-250.
 
It refers to supers that had been in use for over 20 years, making the
practice appear to have been about for about 60 years now!  That article
also referred to the use in sterilising supers and bottom boards
contaminated with AFB.
 
I've seen dippers fired with kerosene and with two 2000 watt electric
elements.  The most basic unit is just a tank over a fire, with a
considerably higher consequent risk of fires.  Tidier 'over the fire' units
involve baffling to get more heat transfer into the wax, chimneys up
through the middle, etc.
 
There have been several designs in NZ Beekeeper mags over the years.  Two
on hand are:
 
Matheson, A.G. 1980.  Easily constructed paraffin wax dipper.  NZ Beekeeper
41(4):11-12.
 
Reid, G.M.; Matheson, A.G. 1978.  Waikato version of a paraffin wax
dipper.  NZ Beekeeper 39(2):27-28
 
Another reference to the method is:
 
Cook, V.A. 1968.  Preserving beehive parts with paraffin wax.  N.Z. Journal
Agriculture 117(1): 60-61.
 
When using paraffin dipping as a preservative, and yet still wanting to
paint the supers, you have to slap the paint on while it the box is still
VERY hot, letting the paint get sucked into the wood.  I've worked with
pre-soaking in Metelex (copper napthenate) as a fungicide, but not sure how
much stayed in/on the wood after the wax dipping...
 
And as there is no inherent fungicidal activity, if the wax surface is (1)
not really 'sucked' into the wood adequately or (2) broken through use,
etc, rot can still set in...  But redipping is a relatively simple matter,
too.
 
For use in sterilising gear, keep in mind that New Zealand does not feed
drugs to control AFB.  When AFB is detected, the 'general' rule is that the
bees and all gear are burned to destroy.  In fact, most commercial outfits
are geared up to wax dip the boxes, floors, lids, excluders, etc so as to
reuse them.
 
For use as a sterilant, the boxes/floors need to stay in the dipper for
about 10 minutes or so.  I can't remember the 'proper' temperatures, but
the rule of thumb is (for both purposes) to keep the wax below the flash
point (good idea that...) but damn hot.  There's a point that there's a
white vapour that comes off the surface of the wax that indicates 'hot
enough'.
 
Buying out an 'infected' outfit and *serious* dipping of all the boxes,
floors and lids has cleaned up many a ready-to-abandon outfit.  You can't
do anything about saving the frames and comb, but the economics are often
such that you can melt out the lot and get enough from the beeswax to get
at least some of the cost of frames and foundation back.  And I've been
repeatedly assured that the beeswax (after going through the foundation
process) no longer has active AFB spores.
 
Steam treatment can also be used, but you've got to have access to plenty
of and for a long enough period (10 to 15 minutes).  I'd be a little
concerned to make sure the steam was baffled about to get/stay soundly in
contact for the full period required.
 
NZ has used scorching of gear in the past, but general concensus is that it
simply wasn't consistently effective enough.  It can be done, the older
guys say, but the line I heard was 'The best way to make sure you've
scorched them properly is make sure the scorching from the inside of the
box meets up with scorching from the outside!'
 
-------------------------------------
          Nick Wallingford
      Bay of Plenty Polytechnic
 (East coast, N Island, New Zealand)
     Internet [log in to unmask]
-------------------------------------