Paraffin Wax for Disease Control and Preservation of Woodware

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.

Fire risk is generally dealt with by having some sort of tightish fitting lid that can be thrown over the tank if it 'flames' and/or a quantity of wet sacking to serve the same 'smother' purpose.

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'.

The boiling point of paraffin is about 360 deg C (680 deg F). At approx 160 deg C (320 deg F), white vapour comes off the surface of the wax, indicating it is hot enough for sterilisation. The wax should be hot enough to bubble around the equipment when it is immersed, rather like in deep-frying in fat. Don't boil the wax too vigourously of course because of the fire danger. Ten to fifteen minutes immersion are required for sterilisation.

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.

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!'