Cleaning perspex crownboards

Perspex crownboard

Perspex crownboard …

I’ve previously described the perspex insulated crownboards I use. These allow me to determine how the colony is expanding in Spring, or how much fondant remains during autumn feeding, with minimal disruption to the colony. The poly Everynuc I use is also supplied with a semi-flexible clear polycarbonate sheet to be used as a crownboard. Note that the terms ‘perspex’ and ‘polycarbonate’ are almost certainly incorrect, but I’m sure you are familiar with the sort of material I’m talking about (and may even know the correct names for it).

My crownboards have bottom beespace and the polynucs are nominally top beespace. Nevertheless, perhaps because of the inherent flex in these materials or my shoddy workmanship, the bees often start to build wax fillets between the top bars and the crownboard. When replacing the crownboard after inspecting the colony this can trap bees so periodically needs to be removed. If you have one of the blade-ended hive tools this can be used but I’ve found a much better solution is a Stanley-bladed window paint scraper. However, don’t use a brand new blade as it will inevitably catch and stick into the relatively soft perspex/plastic/polycarbonate of the crownboard. Instead use an old and blunt blade which makes short work of the wax and propolis adhering to the crownboard.

Inevitably the bees will have started to refill the gap when you next inspect the colony but at least you won’t be faced with a little row of corpses trapped along the top of the frame. The wax can be collected and eventually melted down in a steam wax extractor and turned into something more useful, like candles, firelighters or soap.

made by Bayer, the German agripharma company, if you bother to read the shrink-wrap plastic that covers it when supplied …

4 thoughts on “Cleaning perspex crownboards

  1. Peter

    Perspex is the trade name (the ‘P’ should therefore always be upper case) used by ICI for a plastic material known as, ‘poly methyl methacrylate’ or more commonly as, ‘PMMA’ or simply ‘acrylic’. I’ve waited for forty five years to find a reason why I attended a materials science lecture on a hot summer afternoon. This is the first time I’ve ever needed to trawl up my plastic polymer knowledge. Thank you – I could by dynamic in a pub quiz team.

    Have you tried wiping the acrylic with a cloth smeared with a small amount of petroleum jelly? That should make it easier to remove any wax build up and will fill any slight scratches (well that’s the theory – the lubricants lectures were much more interesting).

    1. David Post author

      Thank you Peter … very useful. Although I don’t think I’ll go back over the last 100+ posts and substitute perspex for Perspex (or for that matter poly methyl methacrylate) I will endeavour to use it properly in the future.

      I’ve not tried using petroleum jelly. When I first built them they were fantastically clear. Taking the roof off was like opening a window directly into the hive. The last thing I wanted to do was obscure the view in any way (before the wonders of Photoshop a thin smear of petroleum jelly was often used to achieve a soft focus effect in photography). I’ll try … they’re so scratched and tatty now it can’t make the view much worse. Even though they’re nothing like as clear as they were originally, I still like being able to see the activity without opening the hive.


  2. Mike

    Hi, Great to hear practical experiences with poly nationals. It’s very hard to find anything other than marketing and reviews by people who haven’t actually used them.
    I bought one of the Bee Hive Supplies poly nationals as an experiment and had great success. It’s properly compatibly with wooden equipment – the tops and bottoms of the boxes being flat. Essential as I like to use framed queen excluders & clear crown boards with bee space. (The sheet of correx supplied with it will find another use.) It has good thickness of material all round – only two sides have recesses and they still seem quite thick. After a shook swarm this spring the bees really did fill it wall to wall with brood.
    Only downsides:
    I don’t like the floor – the meshed area is quite small, the entrance is unusual and takes a custom piece of polystyrene to close it off. Also the mouse guards are supposed to slide in horizontally which I’m not sure will work well – I might try it on a wooden floor for the winter.
    Cleaning – as with all poly hives you can’t blow torch it. I’ve invested in a huge plastic tray so after scrubbing it I can soak each side of the brood box in the recommended bleach solution.

    BTW For painting B&Q will mix up 250ml sample pots in any colour you like and it’s cheaper by volume than the tins on the shelf.

    1. David Post author

      Thanks for these comments Mike. I think this comment would best be linked to the post on Swienty poly Nationals but I can’t see a way to easily move it. I’m pleased other designs/makes are also satisfactory. I’ve only got experience of the MB floors which are OKish as far as the meshed area is concerned, though I don’t like the way the entrance block works … again a custom design but with no way to reduce it to a very narrow entrance for protection from wasps or robbing. The Hammerite Garage Door paint costs ~£1/box for two coats and looks very smart … only time will tell whether it is sufficiently hardwearing.

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