Oxalic acid sublimation devices: there are too many devices in the market and home made. Toni Imdorf and others tested several devices. They found a wide range of efficacy when tested several devices. There were only a couple provided consistent results. One of them is Varrox device.
The trick you need to follow the instruction to get consistent  results. One step in the instruction mostly ignored is to dip the cup in cold water in between hives to cool it off before putting the acid for treatment. This is to protect the person from exposures I the acid during application and reduce the heat to start all over again every time you apply to a hive. Thus following applying the acid crystals the temp will increase and acid will sublimate. Keep in mind acid fumes are spreading in the hive passively.

In our system my beekeeper and I worked on standardizing the system by taking care of several points:
1. Use one device that is available and tested. Based on Imdotf advice we used Varrox

2. Keep the heater on at all times during application to minimize time and energy used for heating in between hives

3. Use airflow to push the acid into the hives. With adjusted air spread enough to push the acid and maintain the temperature inside the contraption around 160+/- 10 C to keep OA as a gas

4. For safety we don't insert the cup of Varrox in the hive but only a short pipe to blow the oxalic acid into the hive. This you also don't BBQ bees or Queens.

5. The oxalic acid fumes getting out of the pipe has a temp with 20C to avoid burning bee wings. It also penetrate the bee cluster and provide better exposure of bees to the acid

6. This modified device can deliver the oxalic acid dose 2-3 g in 90 sec . By that time you will see the gas coming out of the top entrance. You then remove the applicator from the hive otherwise you continue to below air inside the hive instead of acid

7 to ensure applying a consistent dose we developed tablets to use (optional). Safer clean and easy.

8. The design has 4 outlets to apply OA to 4 hives at a time. Also we have single unit or 2 units

At all steps during the design we monitored temp, air flow, recovery of acid coming out of the tube.  We did not want to use electronics sure to acid is crossover and can destroy them. We used electronics to convert the voltage and amp to meet required ones for the Varrox. The idea is also to be safer for use no electrical shocks... Or......

I am sure there are devices out there could work. For us we needed a standard system tested, safe, efficient to be used in commercial operation as well as small operations and provided measurable consistent results.


Medhat Nasr


Edmonton Alberta Canada

This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail.

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html