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The following was written in 2012 by Andy Sivell, and published in his 'Diary of a Nervous Beekeeper' that same year. Although the prices may have changed slightly (and Maplin, sadly, has gone the way of so many high street retailers), both the subject matter and his advice remains as relevant today as it was then, and I'm therefore republishing it – with his permission – in its original format.

One of the joys for someone like me, who’s not very technical, is being told by builders, electricians and assorted handymen how easy it is to do something I find utterly baffling. Need to fix that leaking gutter? “Well, what you want to do is…” they start, before rabbiting on about soffits, fascias and rafters, but without really telling me what they are, where to buy them, or how one bit fits to the next.

Honey warming cabinet from an old fridge
"Just get an old fridge, sling some light bulbs in it, and Bob's your uncle: saved yourself the bother of having to read any further..."

I’m now going to add ‘building a honey warming cabinet’ to that category, because if I had a pound for every textbook, magazine article and website forum I read that talked about processing solidified honey in the same breath as remarking that, “you can easily convert an old fridge into a honey warming cabinet” – without explaining how – then I could have saved myself the trouble and bought one from Thornes.

How?! How do you convert a fridge into a honey warming cabinet? How do you ensure that it’s not leaking CFC gasses? How do you know whether it’s safe to drill holes through the sides? How do you wire it? How do you do prevent it from overheating? What I wanted was an idiot-proof guide.

But there wasn’t one.

That is, until now, ladies and gentlemen. I hereby present ‘The Nervous Beekeeper’s if-you’re-not-technical-you’re-in-good-company, Complete Beginner’s Guide to Building a Honey Warming Cabinet from an Old Refrigerator’. It may not be funny, but by golly it’s comprehensive. I’ve assumed that you can wire a plug, but not much else. Oh, and although I actually did everything described here myself, you follow these instructions entirely at your own risk (read the important notes at the end of this blog post). As and when others weigh in with their own advice – or contradict mine – I will publish their notes under ‘Comments’.

Click here for a printer-friendly version of this article, with more pictures and funnier captions (well, more pictures).

Making a honey warming cabinet from a refrigerator – materials list

I used the following (prices correct in 2012):

  1. Whirlpool fridge model ARC 0460 – free
  2. 5m 3-core 0.75mm2 round (electrical) flex cable; Homebase product code 386688 – £10.99
    (or just buy the 3m you actually need for £1.49 a metre from Maplins, I later found out)
  3. 13 amp fused plug – free (attached to fridge)
  4. 2x 100W BC daylight bayonet fitting light bulbs JD024T3 – £2.50 each
    (Possibly a bit over the top. You can achieve the same result with two 60W bulbs from Toolstation, price 98p each …I found out later)
  5. 2x light fittings to suit above; batten holder T2 straight; Toolstation product code 46677 – £1.05 each
  6. Corgi PCS Dual Pipe/Cylinder Thermostat; Toolstation product code 68281 – £8.98
  7. DC Brushless fan (as used to cool PCs); size 60 x 60 x 25mm; Maplin product code ZT88 – £7.99 (or pinch one from an old PC. See ‘Wiring the thermostat, fan and light fittings’ below)
  8. Power Pax UK 12V DC 500mA UK PSU (transformer); 2.1 x 5.5 x 12mm output connector, Maplin product code N93JU – £9.99
  9. Electrical connector block – free (lying around garage)
  10. Mastic – free (as above)
  11. Electrical and gaffer tape – free (as above)
  12. 1 inch wood screws – free (as above)

Total cost: £45.05 (or less, prices correct 2012)

Step-by-step guide to building a honey warming cabinet out of an old fridge

These instructions are for converting an old fridge into a honey warming cabinet using a pair of 100 watt light bulbs as a heat source, a thermostat to regulate the temperature, and a PC cooling fan to circulate the air and avoid localised hot spots. Wiring is based on UK (United Kingdom) protocols.

Finding a suitable old fridge

Whirlpool fridge model ARC 0460
Whirlpool fridge model ARC 0460

Refrigerators contain pollutants, and must therefore be disposed of responsibly, often via local recycling centres. These usually don’t take kindly to you skipping up and helping yourself. So how do you get hold of one? Well, I turned to my local independent electrical retailer [www.goddardselectrical.co.uk] Goddards Electrical of Saffron Walden. I guessed correctly that they receive a steady supply of old fridges and freezers from customers buying new ones, and as it turned out were only too happy to throw one in my direction. For several weeks I haunted their yard, searching for a small fridge with no icebox and as much internal space as possible.

R600a sticker on compressor
R600a stamp on compressor indicates that system uses Isobutane

Old, old fridges still contain CFC gasses, which are highly damaging to the environment. Newer fridges use Isobutane (R600a), which has negligible ozone depletion potential – but is explosive if mishandled! Goddards told me to look out for one with ‘R600a’ printed on the little sticker on the black tank at the back (the compressor). Eventually I found a Whirlpool fridge, model ARC 0460, that fit the bill perfectly.

Prepping and drilling

The next challenge involved trying to establish how much of the fridge’s internal workings to keep. Was it safe, for example, to drill holes through the sides and back? And how should one attach light bulbs and the thermostat to the internal walls?

Back of fridge, showing component parts
The black grill across the back is the condenser. The black tank at the bottom is the compressor.

Home brewing forums supplied the first answer. They use old fridges for – well I’m not entirely sure what exactly – but it seemed to involve drilling large holes through the side walls, so I was able to determine that if your fridge has a grill (called a condenser) on the back it’s probably safe to drill through the sides because you’re unlikely to encounter any pipe work. That said, this only really matters if you’re keeping said condenser and attached compressor. I actually completed the conversion of my fridge before deciding to remove both after reading on Wikipedia about the highly flammable, and potentially explosive, qualities of Isobutane [http://en.wikipedia.org/wiki/Isobutane]. Sparks from sawing the pipe work could ignite the gas, so a refrigeration engineer advised me to use metal snips to cut the pipes, and to do so outside. The small amount of gas thus released was relatively harmless to the atmosphere. The rest of it just unscrewed. He also pointed out that the compressor contained oil, so it had to be disposed of carefully at my local recycling centre.

As far as attaching things to internal walls was concerned, none weighed that much, so I found that wood screws worked perfectly well.

Fixing the component parts in place

In an ideal world the internal dimensions of the fridge would have allowed me to pack it to the gunnels with 30lb buckets, with just a few inches to spare for the heat source and thermostat. Although my fridge had a commendably voluminous interior, neatly parking 30lb buckets in it in such a way that the light bulbs wouldn’t be touching them, heat could circulate freely around them, and honey wouldn’t spill out of them, proved about as easy as - well, storing a turkey at Christmas. In the end I decided that warming two 30lb buckets at once would be more than sufficient. Which, given that in nearly three years of beekeeping I’ve only managed to produce two-and-a-half buckets of honey in total, probably wasn’t too unambitious.

Batten holder T2 straight Toolstation product code 46677
Heat source/light fitting screwed into side wall and floor. Gap in hole sealed with clear mastic.

That decision made, it was relatively easy to work out where best to place the two light fittings, thermostat, heat sink, and fan (see picture). I placed one light fitting on the floor away from where the buckets would stand, and the other on the wall above and to one side, with the fan high on the wall opposite, pointing down slightly to circulate the warm air. All reference sources agreed that the thermostat should be positioned centrally to more accurately measure the temperature. It also needed to be attached to a heat sink.

At this point I should flag my indebtedness to 'Steve' (not necessarily his real name, although it is), a fellow EBKA member who a paid a heavy price for striking up a casual conversation with me at this year's Essex County Show and letting slip that he’d already converted a fridge into a warming cabinet. His subsequent, and very detailed, written instructions not only bridged huge gaps in my own research, but also included the names of parts suppliers, catalogue numbers and prices.

Polystyrene heat sink holder
Polystyrene was cut using a fret saw and smoothed using fine sandpaper. Heat sink was an empty 200g Nescafe Gold Blend jar.

It was Steve who pointed out the need for a heat sink, and who suggested that an empty coffee jar filled with water would serve perfectly. I fashioned a jar holder out of cast-off polystyrene, and attached it with a long bolt to the raised block behind where the compressor would normally sit.

The fan was a standard 9 volt 60mm x 60mm PC cooling fan bought from Maplin, although in the unlikely and frankly bizarre circumstances of my ever building another honey warming cabinet I’d pinch one from an old PC. The problem was that – again – everyone advised me to use a PC fan, but no-one explained how to attach it to the fridge or how to wire it.

DC brushless fan Maplin product code ZT88
PC cooling fan fixed using two long bolts attached to IKEA kitchen shelf brackets screwed into the wall

Attaching it to the one of side walls actually turned out to be surprisingly easy, using two thin bolts and a couple of tiny IKEA shelf brackets (see picture). A very helpful assistant at Maplin then told me how to wire it and which transformer type to connect to.

Wiring the thermostat, fan and light fittings

PC fans tend to have three wires attached to a tiny plug. Transformers tend to be moulded into a three point plug at one end, from which two wires, encased in plastic and fused together, emerge and attach to another – mismatching – type of plug. (I’m not going to pretend that I know the correct name for either plug type, and it doesn’t really matter). Cut the little plugs from the ends of both the fan and transformer wires. Examine the transformer wires closely and you’ll see that one side of the plastic casing has white dashes painted on it. The fan wires are coloured red, black and yellow. Attach the white dashed wire from the transformer to the black wire on the fan, and the red wire from the fan to the other wire on the transformer. Don’t attach the yellow wire from the fan to anything. Test that it works by plugging the transformer into the mains.

wiring a thermostat
Test rig proved hopeless at providing answers, but remarkably efficient at blowing fuses

You’d think that a thermostat would come with a wiring diagram that spelled out which colour wire is attached to what terminal, and how this in turn is connected to the heat source. Think again.

Corgi PCS dual pipe/cylinder thermostat correctly wired
Corgi PCS dual pipe/cylinder thermostat correctly wired

Mine came with an ambiguous drawing of a straight line, punctuated at three points with the cryptic labels ‘Common, ‘Demand’ and ‘Satisfied’, and interrupted by a little squiggle that was meant to represent a switch. Nor could I find much help online. How you wire up a thermostat varies depending on the thermostat, apparently. Best guesses and trial and error resulted in me blowing the fuse in my garage several times. Understandably deterred, I then went over to Deryck Johnson’s house and blew the fuse in his too. My best advice to you therefore is to buy the same make and model thermostat I used, and to wire it exactly as shown in this wiring diagram, which does label and colour-code all the wires. (You do so entirely at your own risk however. Always use an RCD device when connecting to mains electricity). I eventually got the answers from Steve, to whom I shall remain eternally grateful, and without whose help I would now more than likely just be a wispy lump of charcoal hanging by two threads from an electrical socket.

Corgi PCS dual pipe/cylinder thermostat with improvised heat sink
Fully assembled thermostat attached to improvised heat sink (the jar is filled with water)

Wiring the light fittings was one of the few things I could manage completely unaided. There are three terminals, one of which is clearly labelled ‘earth’. Attach the green and yellow wire to the earth terminal and then the blue and brown wires to each of the other two. It doesn’t matter which way round you do it. I mounted the two light fittings ‘in parallel’, the other way of doing it being ‘in series’. The only difference is that ‘in parallel’ both receive power directly from source, whereas ‘in series’ the power flows through one light fitting before going on to the other. I used a connector block to connect the wires from the thermostat to the light fittings.

Initially I used old-style bayonet fitting 60 watt light bulbs to supply the heat, but I wasn’t convinced that they were powerful enough, so replaced them with (much more expensive, and harder to find) 100 watt bulbs. Indeed, 100 watt bayonet fitting light bulbs proved so hard to find (because EU legislation is in the process of outlawing them) that I had to resort to ‘daylight’ bulbs at £2.50 a piece.

Calibrating the thermostat

The only thing left to do after all this was to calibrate the thermostat. It came with a temperature dial on the front, but I presumed that it may not be that accurate. Using a garden thermometer that records highs and lows I therefore set the thermostat to first 30, then 40, and finally 50 degrees Celsius (oC) and recorded the actual ‘on’ and ‘off’ temperatures inside the fridge. From that I established that 50oC on the dial equated to an actual temperature range of 46-54oC.

The big roll-out

Fridge converted into honey warming cabinet
Cabinet doubles as naff Christmas decoration

You know you’re being indulged when your enthusiasm for having achieved something obscure is matched by family and friends not even remotely involved in the process. Of course it’s perfectly possible that they were all just relieved to be finally getting their hands on some honey, having been promised it for two years. Nevertheless, while even they could then only muster polite interest in my subsequent dissertation on the journey their honey had undertaken, all agreed that it looked good and had retained its original flavour.

Long before I’d finished I began to think about honey jar labelling. Now I run (among other things) a studio with full design facilities, so I wanted to know what the precise food labelling regulations are regarding label dimensions, font type, letter size and width.

“It’s all available online,” I was told.

Yeah. About that…

Print this blog post

View and print the thermostat wiring diagram

Important: As ‘hilarious’ as these instructions may be this next bit is deadly serious and you should read it carefully, because if it ever comes to it, it is what I will read out in court.

Electricity is dangerous. Hot light bulbs are dangerous. A combination of electricity, hot light bulbs and liquids is potentially fatal. Fridges are not designed to have done to them what is described here. I'm not an electrician. I'm not a refrigerator technician. I'm not even a very good beekeeper. I have no qualifications that have any bearing upon what is described here. You are therefore strongly urged to check absolutely everything written in this blog post with a qualified individual – and to follow their advice over mine. I am not offering advice. I have simply described what I did. I make no claim whatsoever that it was safe, legal, clever or effective.

You should never connect any electrical appliance to mains electricity without using a residual current device (RCD). You should never leave a home-made electrical appliance unattended. You should always consult a qualified electrician before connecting anything to mains electricity. Goddards of Saffron Walden played no part in this undertaking beyond supplying me with a fridge and advising me on how to dispose of it responsibly. ‘Steve’ never claimed to be an expert and was completely unaware that I might use his notes as I have. He did not approve this blog post and had absolutely no say or involvement in its drafting or publication. You have been warned.

This month sees the start of foraging in earnest and also the start of swarming.

Although the oil seed rape was only just down the road the bees only worked it for pollen. The bees foraging for nectar went in the opposite direction. I am now beginning to wonder if modern varieties of rape have significantly reduced amounts of nectar.

Whatever it was they preferred, half the hives worked it vigorously. One hive got up to four supers and the others to two or three.

The colonies which only just made it through the winter have struggled to reach supering size but as two of these have 2016 queens and will be requeened this season.

The first swarm I was called to remove was a poor little bedraggled specimen hanging from a tree near Thaxted Fire Station. It had been there several days and was trying to set up home out in the open.

Thaxted swarm

It was nearly dark when I arrived so it had to wait until the next morning; a night of torrential rain and it was still raining next day. Half of them had been washed down in the night and were comatose mixed in with the recent lawn mowings. It was a ladder job to reach the little swarm and I then swept up as many as I could from the ground hoping that once they were returned to the bosom of their family they would become resuscitated. This did in fact work and most of them recovered. They were a pathetic little bunch when they were eventually hived; just over one frame of 14 x12 in a nucleus hive.

The rape finished flowering two weeks ago and any resulting honey would normally have started crystallizing by now. It’s all still clear which again leads me to conclude that the nectar came from elsewhere. The eventual analysis will be interesting.

I’ve had to perform three Pagden artificial swarms so far with another one to do this week. At the same time as creating the artificial swarm I also take a two-frame nucleus with a queen cell so I have a second string to my bow in the event of a loss on mating flight. The apiary is getting rather crowded now with sixteen hives.

Three flying days in a row now which seemed to herald the glorious anticipation of yet another season but then things turned.  Three weeks of arctic winter has kept them all indoors..

All eight colonies have been flying well and vigorously foraging on the Winter Honeysuckle, the Hellebores and now the crocus. The latter have very deep nectaries so the bees have to stand on their heads and struggle to get their reward.

I have been hefting the hives since the new year just to ensure that their stores are lasting them and all seem to remain fairly heavy.

Unfortunately, the winter oxalic acid treatment was not as successful as I would have liked so I have had to give them another course of Apivar. Weekly counts continue and some hives are now down to two successive zeros whilst others are down to single figures.

The field of rape down the road, easily within flying distance, seemed to have resisted the ravages of the pigeons for a long time but eventually the vermin found it and are now tearing it to pieces.

Once the feeding is all done and the feeders removed, beekeeping becomes a more relaxed pastime. In effect, there is little to be done apart from the oxalic acid varroa treatment and repairs to equipment.

Oxalic acid will achieve an approximate 95% knock down of varroa. Not a complete cure but sufficient to seriously deplete their numbers before the brood rearing starts in earnest.

I mix a 50:50 solution of sugar water and add 18.75g of oxalic acid dihydrate to the mix. This is then dribbled 5ml into each between-frame seam of bees. Having the crown board up on matchsticks makes its removal almost vibration free.

The acid will only kill the mites which are outside the brood cells and cannot touch any beneath a wax capping. It is best therefore to do the treatment after a seriously cold spell which will have reduced the queen’s laying to almost nil. i.e. less sealed brood and hidden varroa.

Charging needle-less hypodermic
Trickling oxalic acid between the frames

 

 

 

 

Each colony can be done in less than a minute and the hive quickly closed up again before the cluster suffers heat loss.

The varroa trays go underneath just to give me an indication of efficacy.

This treatment can only be done once a year as the acid burns the carapace (the dorsal exoskeleton) of the bee and must also burn the bee’s mandibles.

In the workshop I have reinforced the bellows on the stainless-steel smoker, repainted the numbers on the hive roofs and made a new aluminium cover for roof 8.

Apple weekend at Audley End House was once again a terrific weekend. English Heritage say the foot-fall was 4500 over the two days. Talking bees, pollination and honey for two days solid was very tiring but greatly rewarding. One very interesting visitor who introduced herself to me was none other than Ted Hooper’s granddaughter Lauren who told me that sadly, they no longer have a beekeeper in the family.

Winter Feed 2017

The bees have all had their usual amount of winter feed; 8l of sugar solution and 3l of waste honey. Hive 1 had the container of Apikel which I was given. Interestingly not all of this had been taken down but it could have been a case of them not liking it. I removed the feeder, gingerly removed the middle frame to find brood in all stages so carefully replaced it knowing they were queen-right. Had there been a problem, some of the earliest brood would have had emergency queen cells. As it was, the reason was that apart from the brood in the centre, the brood box was chock-a-block with stores.

Three other hives have only taken some of their feed and I’m hoping they are in a similar state because they had ample nectar flowing from all the volunteer borage in the field behind. As Tom, the farmer, freely admitted to me, "Yes, we cocked up there."

Volunteer borage amongst the wheat

The Apivar is almost at the end of its recommended insertion time but the varroa are still dropping high weekly figures. Some are still up in the hundreds per week.  Hopefully they should fall to single figures any day now and the strips can be removed.

All the honey has now been extracted. This year was the first year I noticed such a strong floral smell as I lifted each crown-board. It was possibly the hawthorn which has a strong pungent aroma and is a most erratic yielder. All the honey this year is dark in colour, strong and loth to crystallize. I fear my creamed honey regulars are going to have to get used to clear honey .

One super was simply fitted with eleven starter strips rather than foundation. As the bees drew out this 100% fresh comb, one frame was removed and the remaining ten spaced a little more widely. This gave a slightly wider and heavier comb to cut into blocks. Much of it was also drone comb which, with its larger cells, meant less wax and more honey.

Having removed all the supers I can now complete my records of honey-yield per hive in order to make my decisions as to which queens to over-winter. Eleven colonies and one nucleus are going down to 8 hives. The queen in hive nine was culled and the colony moved around the apiary further than three feet each time placing it alongside other colonies whose number I wanted to boost. Each time it was moved, the flying bees returned to the hive nearest its old position. This way I gradually bled half the colony into other hives. The remainder was then united in its full-sized box with the nucleus colony. Each frame of bees was gently misted with a dilute sugar solution with a drop of oil of lavender to mask the colony aromas and the frames placed alternately into the 14 x 12 box and left for a few days to settle down. This box was then united with hive 1 using the newspaper method. The queen was removed from colony 1 and then later in the evening, this queenless colony was placed above the queen-right colony with a sheet of paper between them. By the time they had nibbled through, their aromas were sufficiently blended as to avoid any confrontation.

The varroa counts have reached scary levels so I decided to treat with Apivar before I feed. Having had Deformed Wing Virus and Chronic Bee Paralysis Virus during the year I thought it best not to just leave it to the beegyms. The hives fitted with beegyms have registered noticeably higher mite-falls but the beegym instructions do say ‘use as part of your integrated pest management’.

Next week we have the ‘Taster Session’ for prospective beekeepers followed by Audley End Apple Weekend. Lots of hard work to finish the season.

Getting an oil-seed-rape harvest gets harder as each year goes by. This year, what the bees were able to forage in the first week of flowering they ate themselves in the five terrible weeks that followed. Fortunately the field beans over the road played a part in bringing the harvest up to an acceptable level. No nice creamy white stuff with which to blend unfortunately.

I have now completed six extraction sessions. Clearer boards, of which I have quite a selection were put on first thing in the morning beneath the full supers. Put them on any later in the day and the bees have had an opportunity to gather more nectar and fill any unfilled or partly filled cells. This is all unripe so raising the average moisture content of the honey.

So, clearer boards on very early then supers gently off late in the day without disturbing them. Next morning can then be devoted entirely to uncapping and extracting with the wet supers going back on late in the evening. Put them on earlier and the sudden blast of honey aroma can cause great excitement with consequential robbing

As an afterthought; how pleasant it is to work with such well behaved bees. Queen selection and rearing means that usually, I can do a brood-box inspection with just one or two puffs of the smoker.