Sciencemadness Discussion Board - Looking for a UK source of aluminium granules for a heat bath

Looking for a UK source of aluminium granules for a heat bath

DavidJR - 8-3-2018 at 16:33

I've seen mentions on this site of using aluminium granules/shot/pellets in a heat bath as a replacement for oil, sand, water, etc. I'd quite like to try this but I'm having issues finding suitable aluminium shot in the UK. Got any ideas?

Bert - 8-3-2018 at 17:33

It's a bit expensive, but airsoft players use solid Aluminum 6mm balls for their "sniper rifles".

https://m.ebay.com/itm/1000-RD-New-Aluminum-Metal-3g-0-30g-6...

Metacelsus - 8-3-2018 at 20:40

It might be possible to make your own if you have a furnace that can melt aluminum (660 °C). See: https://en.wikipedia.org/wiki/Shot_(pellet)#Manufacture

[Edited on 3-9-2018 by Metacelsus]

DavidJR - 9-3-2018 at 04:47

I've seen the aluminium airsoft pellets but like you say that would be pretty pricey to buy enough.

Unfortunately I don't have the facilities to melt aluminium.

yobbo II - 9-3-2018 at 06:29

Try cooking shops. I have seen pellets for sale used for putting into pastry molds (the things you would put jam into when cooked ) to keep them in shape when they are being baked. Also called pie weights.

Yob

Bert - 9-3-2018 at 07:38

I briefly considered making my own, if you have some time on your hands and access to scraps of the Aluminum power cable used for mains electric supply, you might source cable scraps from a metal recycling company or an electrical installer?

The individual strands of conductor inside the cable are soft, pure Aluminum and very easy to shear. If one were to strip out and unwind several pounds of these Aluminum conductors and more or less straighten them out, one could feed several at a time through a sheet metal shears with the material stop set just about 1 diameter of the individual strand, producing little cylinders about as long as wide.

Once you had enough of these pellets, you could tumble them in a ball mill (rock polisher!) until the cut ends were well rounded, or possibly just use them as they came out of the shears if the sharp cut ends were not objectionable.

DavidJR - 10-3-2018 at 10:41

Hmm that sounds like a lot of work, I was kinda hoping for an off the shelf solution...

yobbo II - 10-3-2018 at 15:34

AAAAAAAAAAAAAaaaaaaaaaa no it would not!!

Would copper do the same job just as good. Easier to obtain the cable too.

Yob

[Edited on 10-3-2018 by yobbo II]

LearnedAmateur - 11-3-2018 at 06:05

Copper would be even better in fact, higher thermal conductivity and lower heat capacity, meaning it takes less energy to reach a higher temperature.

DavidJR - 11-3-2018 at 06:16

True, but copper has roughly 3 times the density of aluminium, and it's more expensive per unit mass. So a copper granule bath is going to be more expensive.

Sulaiman - 11-3-2018 at 06:20

Copper would give a lot of 'bouyancy' as it is quite dense.
Perfect spheres conduct heat poorly,
shapes more like a water drop on plastic would still be smooth but conduct heat better,
- very oblate spheroids.

I hope that you find a suitable medium for high temperatures as I'm going there soon.

What temperatures do you wish to operate at ?
(e.g. infra-red or hot-air can boil Az. H₂SO₄, mantles can heat to near glass m.p.)

DavidJR - 11-3-2018 at 06:42

I won't be routinely doing anything above around 200c, on occasion might go up to the BP of azeotropic sulphuric acid. I want something for general use which is less messy than oil (and less hazardous re accidental introduction of drops of water) and has better thermal conductivity than sand. Preferably reasonably cheap too...

Aluminium (and other metals) in powder form is relatively easy to get but that would be messy and possibly an inhalation hazard depending on particle size.

[Edited on 12-3-2018 by DavidJR]

Bert - 11-3-2018 at 06:42

Quote: Originally posted by DavidJR

I'm having issues finding suitable aluminium shot in the UK. Got any ideas?

Perhaps you could look OUTSIDE the UK, if none are to be found and you do not have the time to make your own.

Or you could call a few metal salvage/recycling businesses and ask if they receive Aluminum punch press scrap such as this.

DavidJR - 11-3-2018 at 06:49

"Shipping: Does not ship to United Kingdom"

DavidJR - 11-3-2018 at 06:54

I have emailed this company: http://www.lowdenlimited.co.uk/PureMetals/Aluminium.html but yet to receive a reply.

S.C. Wack - 11-3-2018 at 08:08

BTW are there BB guns in Britain? 2 kg of copper coated steel .177 caliber shot goes for $8.49 with free shipping on USA amazon.

DavidJR - 11-3-2018 at 08:53

Steel is much less thermally conductive than aluminium or copper, and as mentioned above perfect spheres aren't great for heat transfer either.

edit:

Though I suppose the real question is would steel work anyway?
You can get steel bead blasting media for cheaper than that, and some types are irregular rather than perfectly spherical.

[Edited on 11-3-2018 by DavidJR]

Twospoons - 11-3-2018 at 12:44

Have you tried a machine shop? They may have aluminium swarf you can try for free.

DavidJR - 12-3-2018 at 09:33

Got a response from Lowden Limited, they have quoted £54 per kilo excl vat and shipping. Eek! Perhaps not.

I also contacted Guyson, who manufactures/sells shot blasting equipment and media, and they have quoted about £310 incl shipping for a 25kg bag of their Alusad A16 aluminium granules. That is a more reasonable £12.40 per kilo but I really don't need 25kg so unless anyone wants to group buy then that's a no-go.

[Edited on 12-3-2018 by DavidJR]

yobbo II - 2-4-2018 at 13:49

If you were to get some Al drink cans and cut into small squares using a scissors, or perhaps cut lots of strips, curl the strips and them cut to give each square a three dimensional lift.

Getto

Sulaiman - 2-4-2018 at 16:53

At those costs it is worth buying a heating mantle.
I use one of these https://www.ebay.co.uk/itm/500ML-250W-Hand-Woven-Adjustable-...
one of these https://www.ebay.co.uk/itm/New-4000W-AC-220V-SCR-Voltage-Reg...
and a tin can.
Less than £10 total.
(magnetic stirring still under development

S.C. Wack - 2-4-2018 at 18:09

If anything is to be cut, it should be rod such as from hardware stores here.

DavidJR - 3-4-2018 at 14:43

Quote: Originally posted by Sulaiman

At those costs it is worth buying a heating mantle.
I use one of these https://www.ebay.co.uk/itm/500ML-250W-Hand-Woven-Adjustable-...
one of these https://www.ebay.co.uk/itm/New-4000W-AC-220V-SCR-Voltage-Reg...
and a tin can.
Less than £10 total.
(magnetic stirring still under development

You know what, that's not a bad idea...