A few people on the forum have tried different cleaning techniques:
I remember @busso put them in the dishwasher which seemed to help the Flow Frames, but left a big lot of gunk in the machine.
Our Cleaning/Sterilisation faq has been updated on our website:
I know it refers to a few other things other than mold, but thought you might find the chemical information useful anyway.
Under normal conditions, it is not necessary to clean your Flow Frames (click here for information on routine cleaning and storage of Flow Frames).
In some jurisdictions cleaning may be necessary prior to sterilisation as a means of disease control—please contact your local department of primary industries for region-specific advice.
Cleaning and wax removal for sterilisation
Following are some options for removing wax and propolis from Flow Frames. We have tested these treatments and found them to have no effect on the mechanical function of the product.
Prior to treatment manually remove excess wax, by placing the frames on newspaper and scraping. We have achieved best results at wax removal by disassembling the Flow Frame prior to treatment, however, please note that this will void your warranty.
These are maximum exposure recommendations and should only be used under conditions where sterilisation of the frames is necessary. Do not exceed temperature and time for optimum function of your frames. Destroy all debris by burning.
#Ethanol is highly flammable. Do not heat ethanol on or near a naked flame.
*The use of casutic solutions (Caustic Soda/washing soda) requires great care and caution. You must use suitable protective clothing, protect your eyes and use rubber gloves.
The safety of your bees is very important—after any treatment of your frames please ensure they are rinsed thoroughly in water and dried prior to storage or returning to your hive.
Please note that if you are treating AFB this is a notifiable disease. Legal requirements differ between jurisdictions. Please contact your local authority for advice on appropriate disease control measures.
In some jurisdictions, it is acceptable to use bleach to sterilise AFB contaminated hive components. Research has shown that immersion for twenty minutes in a solution of 0.5% sodium hypochlorite kills AFB spores and other bacteria. The solution must be in direct contact with the spores. It is, therefore, necessary to remove wax and other debris prior to sterilisation (see above cleaning options).
In some countries, Gamma irradiation is used to sterilise equipment infected with American Foulbrood (AFB). A dose of 10 kGy is sufficient to eliminate AFB spores (Hornitzky&Wills, 1983; Australian Honey Bee Industry Biosecurity Code of Practice, 2016, Pg 11). Flow Frames can withstand a maximum of 20 kGy Gamma irradiation, above this, the plastic will become brittle and the mechanism may fail on harvest.
What you should do when treating with irradiation:
Flow Frames should be exposed to a maximum combined dose of 20 kGy irradiation. This enables 2 rounds of AFB sterilisation at 10 kGy. Some Irradiation facilities use beehives as ‘gap filler’ in larger loads. This means a single round may expose your frames to more than 40 kGy.
We recommend you contact the facility to discuss maximum doses. If you are in Australia (excluding Tasmania) we recommend that you send your frames to Steritech’s Brisbane Facility. This facility is capable of controlling the irradiation dose. If you need to send your Flow Frames for irradiation please mark them clearly for future reference.