I was concerned that treating my Purdue Ankle Biter breeder queen hive with MAQS could potentially harm the queen. Published data indicates Oxalic acid vapor does not have the same risk. Beekeeper Jon pointed out the new Kelly vaporizer to me recently. It has a few features making more user friendly. My new toy (special tool) arrived on Monday, but today was the first time I could give it a try.
The vaporizer comes with about a 10 foot electrical cord and runs on 12v from a car battery. I would have preferred a 20 foot cord so I could do more hives prior to re-positioning the vehicle housing the battery. Adding the extra length will be a quick winter project.
The vaporizer has a built in timer; so no need for a stop watch. Depressing the start switch starts the 2 1/2 minute heating cycle which vaporizes the powdered oxalic acid. During the heat cycle a red LED flashes rapidly. Unfortunately the LED is hard to see in the bright sun. The vaporizer then automatically switches off. The red LED then flashes at a slow rate during the cool down period of about 2 minutes. The vaporizer can be removed after the cool down is complete, however, the hive is kept sealed for another 10 minutes.
The fact that the light was not readily visible bugged me. So last night I took the cover off the vaporizer handle. I could see the red LED was bent over. After straightening the LED back to vertical I carefully re-installed the cover on the handle. The LED now projects above the handle surface. Today I used the vaporizer in bright sunlight. It was now readily visible while blinking.
I did not time myself, but I think I treated 5 hives in about an hour. Another tool in the fight against varroa.