Evaporators & essential Oils
The Nassenheider Evaporator
Phone: +49 3342 303121
Fax: +49 3342 303123
1, Presence of brood throughout the treatment.Timing of treatment during the year
2, Placing the evaporator close to the focus of bee activity and the brood. Bees regulate a constant temperature of 35° C next to the brood, that is why the evaporation rate is largely independent of external temperatures.
1, Two treatments are recommended, lasting 10 - 14 days each. The first should be done in July/August after the harvest, with a repeat treatment before brood rearing ends in September/October.The Nassenheider evaporator consists of three components
2, In cases of heavy infestation or in warmer countries, where there is no clear break in flowering and brood production, at least two treatments, each following a harvest, should be contemplated.
1, A graduated plastic tank that holds the acid.Preparations for treatment
2, A fibrous, absorbant sheet wick (these can be cut from 'fume pads', sold by beekeeping appliance dealers.
3, A ventilated plastic cover shroud that surrounds the wick.
1, Remove any honey supers for extraction before treating the remaining colony.Instructions for use
2, Temporarily cover the mesh of Open Mesh Floors.
3, Install an entrance block with entrance about 125 mm x 9 mm.
1, Detach the ventilated cover.Selection of the wick
2, Fix evaporator in the upper portion of a divided brood frame using two noncorrosive screws. (Nylon nuts and bolts can be used here... M5 or 2BA.)
3, Tilt the frame and slowly deliver 80 cm3 of 60% formic acid into the holding tank using a measuring cylinder, injection syringe or squeeze bottle.
For a continuous treatment of 3 - 4 weeks the evaporator has to be completely filled (180 cm3).
4, Always use a new wick (shown red) for each filling. Insert the wick into the slot in the cover, clip the cover back in place while locating the wick positively in the forked holder.
5, Place the prepared frame inside the first brood-free frame.
6, If the colony is using two brood chambers, a second evaporator should be installed in the second brood chamber in the same position, but on the opposite side of the nest.
7, Within the first 2 or 3 days remove the frame to check the acid level and calculate the daily evaporation rate.
Maintain the following average daily evaporation rate when using 60% formic acid:-
15 - 20 cm3 (ml) in Summer, or 6 - 10 ml in AutumnIf the evaporation rate is below 6 ml per day, the treatment may not be successful!
8, If there is a measurably higher evaporation rate (caused by a large amount of fanning activity) shorten the wick to reduce its size. This will allow the evaportion rate to be brought within the limits in 7, above. If a high evaporation rate empties the chamber in less than 10 days, it is recommended to top up the acid. A higher rate of evaporation or a longer lasting treatment causes no apparent harm.
Wicks are nominally 50 mm wide.Important... The cover of the main tank is welded and must not be removed, its sealing is essential for proper functioning.
Small wick:- (50 mm x 58 mm) has an effective evaporating surface of 36 mm x 50 mm = 18 cm2 per side.
Large wick:- (50 mm x 82 mm) effective evaporating surface 60 mm x 50 mm = 30 cm2 per side.
Manufacturer's note, due to the cutting process the sizes of the wicks may vary by a few millimeters. These small area differences are too small to affect the evaporation rate seriously. The other influences on the evaporation rate (ventilation by the bees etc.) are always much larger.
Generally the smaller wick is used... (50 mm x 58 mm). However if the evaporation rate is found to be below the recommended rate of 15 ml per day in Summer or 6 ml per day in Autumn), the larger wick (50 mm x 82 mm) should be used. If the rate is too high (> 40 ml per day in Summer and > 20 ml per day in Autumn), the wick should be shortened to reduce evaporation.
1, Pay attention to the formic acid manufacturer's safety instructions!Safety is important always have available... a two litre plastic soft drinks bottle full of plain tapwater. Stand this upright, and with it's top OFF, close by where you are working. In the event of an accident the water can be poured immediately onto a splash or the bottle can be squeezed to force water into an eye that has had a splash. Hopefully you will never need to use it, in which case it can be drunk.
2, Wear Neoprene safety gloves and safety glasses while working with formic acid, do not inhale the vapour.
3, Formic acid causes cauterisation (Burns) on contact with skin.
4, Splashes on the skin or in the eyes should be drenched with copious amounts of clear water, consult a doctor after contact with formic acid.
5, Keep formic acid away from children!
Thyme oil,One problem that I have considered is that some oils may form a skin on the surface of the wick and thus limit further evaporation.
Methyl salicylate (Oil of Wintergreen)
Another 'aromatic' is Turpineol, which is referred to in some elderly texts as a treatment for acarine.
Written... 25 Feb - 05 Mar 2002