Disturbing technology: the defrost-o-plate
A few years ago, my dad bought a mad thing from JML (they advertise on TV and their slogan should be “we sell weird shit for your house”). I dubbed it the defrost-o-plate: it claimed to defrost food in record time, without heat. Bollocks! I cried. My dad showed me it in action. I bought one for myself.
My defrost-o-plate (I’ve no idea what it’s officially called) is a rectangular metal tray, painted matt black, with a half-dozen grooves in it (although as the photo shows, there are other designs out there). You don’t need to heat it up, it has no power source, it doesn’t seem to be made of anything unusual, and it is clearly of human origin: the feet fell off within days. And I have absolutely no idea how it works.
I tried an experiment: I got two ice cubes and put one on the defrost-o-plate, with the second ice cube on a normal plate. After half a minute, the normal-plate ice cube was starting to look a bit shiny; the defrost-o-plate cube was a puddle of water. If I leave a couple of steaks out to defrost, they take a few hours; on the defrost-o-plate, half an hour.
Naturally, I think it’s a great thing – but my complete inability to work out how it does its magic is driving me daft. There are lots of sites offering defrost-o-plates on the net, such as this one, but nobody tells you how it actually works. So I’d like to turn this over to you, as you’re all much smarter than me. How can a bit of metal perform such magic? Is there a scientific explanation, or is it witchcraft?
68 Responses to “Disturbing technology: the defrost-o-plate”
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GillKaye on November 14th, 2009
I’ve spent so long happily reading this, and discussing heatsinks etc etc with the motley assembly of people here, with their varied knowledge of Physics, that the mini-chicken-fillets have defrosted all on their own ……..
GillKaye on November 14th, 2009
(I wrote ‘ten’ in the human slot, and upset the finer aspects of the site … SORRY!)
I’m going to bed now, night all xxx
Gary on November 16th, 2009
> the mini-chicken-fillets have defrosted all on their own
OH MY GOD! YOU HAVE DISCOVERED SPONTANEOUS DEFROSTING!
It’s not as dramatic as spontaneous combustion, I’ll admit.
Anonymous on November 17th, 2009
the plate is a slab of steel which absorbs heat from the air. (metal is a very good conductor of heat, and air is about the worst.)
mupwangle on November 17th, 2009
Yes, but steel is crap for that sort of thing. It’s aluminium usually.
tm on November 18th, 2009
>the plate is a slab of steel which absorbs heat from the air. (metal is a very good conductor of heat, and air is about the worst.)
yes, but that’s true for any bit of metal, and as we pointed out before this idea works with any bit of metal juts not as well (I believe frying pans was the example we used). I know it’s a long thread, but please try to keep up…
And I too expect it was something other than steel tool – if only because steel is really quite heavy for use around the kitchen for more than cutlery. More likely something like aluminium as David says.
tm on November 18th, 2009
>absorbs heat from the air
Actually, before someone else jumps on it, that is really nonsense – but I can’t be bothered with a physics argument. Suffice it to say most pieces of readily available metal would work to some extent.
Dave The Rave on January 10th, 2010
The reason it works so well are as follows:
1) (As already pointed out) it uses a metallic substrate. Most use Aluminium as it’s a good thermo conductor. That’s why electronic component heat sinks are made if it; better ones are copper based, but cost loads more.
2) The groves in the design increase the surface area of the material thus exposing more of it to the air and increasing it’s efficiency.
3) (And this is the nice bit) JML have used a black (again because black is a better thermo-radiator, better that the white used to paint your radiators with at home) ’super-thermo conductor’ apparently the same stuff as used by NASA et al., to cover the base metal.
I found this article as I wanted to get hold of a tin of the stuff to paint some heat-sinks with…
I hope this helps.
BTW: I use my JML Defrost-O-Matic what-ever-it’s-called as a laptop cooler too. Just sit the laptop ontop of it and it keeps things at just the right temperature!
Lots of love,
Dave xxx
benjiboy on January 14th, 2010
any body ever wonder how planes keep from forming ice?
the answer is aluminum.
especially when treated with a finishing agent.
same thing that melts your ice or frozen chicken.
Gary on January 14th, 2010
This is my favourite post… ever!
mupwangle on January 14th, 2010
My chicken is rarely defrosted by planes.
Why would I want my ice defrosted? Surely I would just buy water? I suppose if I wanted to store it for a very long time and had no access to big plastic bottles. Or if I wanted to transport my ice somewhere and had no refrigeration equipment.
Stephen on January 17th, 2010
Actually planes are kept ice-free by big de-icers that spray the wings before take-off; aluminium no less susceptible to ice than any other metal.
Squander Two on January 18th, 2010
Surely the some properties of aluminium that make it good for defrosting in the warm also make it quicker to ice up in sub-zero temperatures.
Metal on January 18th, 2010
I honestly am going to suggest this is some form of Witchcraft…
These things are manufactured far away in a small African village where teams of witch doctors are lined up in an assembly line and spray their voodoo juices using chicken’s feet on the metal as it goes past them on the assembly line before being packed in a box and shipped to the developed world… :| scary but its true!
(Great post by the way!)
Squander Two on January 18th, 2010
Modern outsourcing is getting really ridiculous if the Caribbean is offshoring its voodoo to African witch-doctors.
mupwangle on January 18th, 2010
They’ve had to since the earthquake, unfortunately.
the bishop on February 5th, 2010
the plate is made from “krakiti” a rare type of metal found only at the base of the krak tree in rhyll north wales.j.m.l the popular pop group discovered it while looking for their lost budgie in 2007 duing a cub outing.they coated it with black dulux silk and now market it as “magic defrost” avail in all good stores
sidney pwatier on February 6th, 2010
the bishop is speaking utter garbage .Krakiti,is also available in abundance at the entrance to the dhss benefit office in prestatyn