Sciencemadness Discussion Board

Cutting sodium 25lb ingot

jamit - 24-8-2014 at 02:41

Does anyone have any experience in cutting a large 25lb ingot of sodium? I realize this is an enormous amount...but I was able to obtain it and want to cut the sodium into manageable amount...preferable into 1lb chunks.


I suppose I can just try cutting it with a steel knife, but before I try, I would like some help and precaution I should know on how best to do this.

Fantasma4500 - 24-8-2014 at 03:54

about 12kg?? wow
perhaps you could try using a saw, depending on its width and so forth, ofcourse.. perhaps hammer it, as its relatively soft you could perhaps hammer it into a spiky shape that would be easy to break off? please look deep into this before grabbing a hammer.. burning sodium is bad news, especially with 12kg
but with 12kg you really gotta mind where you put it.. one drop of water could potentially set the entire thing burning

bismuthate - 24-8-2014 at 04:39

I have no experience with this but if you did use a knife I would use the largest unserated knife you have (if you have a stainless steel axe or large hatchet that would be better) slowly with a lot of force on it (no striking it with the knife).
EDIT: you know what just get a big unserrated blade the knife bit doesn't matter. Use a butcher knife, a katana (actually pretty good for this occasion),, a really big straight razor (also pretty good) just what ever you can find.

[Edited on 24-8-2014 by bismuthate]

unionised - 24-8-2014 at 06:05

Among the things I'd not want to deal with is sawdust made from sodium.
Roughly what size/ shape is the ingot?

BromicAcid - 24-8-2014 at 06:06

For large chunks of lithium I have seen it done with a wire knife, looked like a wire cheese slicer but I do not recall if it was serrated or not. I think it was just really thin. Considering they used it for cutting lithium which is harder it seems like it should make quick work of sodium. Plus it shouldn't build up heat from friction.

S.C. Wack - 24-8-2014 at 07:06

Going to beating something into it with a sledgehammer territory, almost a 9" cube.

subsecret - 24-8-2014 at 08:11

First, get a bucket of dry xylene ready...

IrC - 24-8-2014 at 13:25

If you are going to try sawing thus generating fine particles I think it would be best if it were completely under mineral oil at the time.

Pyro - 24-8-2014 at 15:30

melt it under oil, pour it into a long mold under oil, then you can cut off pieces with a knife.
how about a chisel?

jamit - 24-8-2014 at 16:09

Quote: Originally posted by unionised  
Among the things I'd not want to deal with is sawdust made from sodium.
Roughly what size/ shape is the ingot?



The ingot is roughly the size of a 5 gallon bucket.

Amos - 24-8-2014 at 16:15

Maybe take some good hard wire and pull it down and through from both sides? And use a warmer environment if possible.

careysub - 24-8-2014 at 16:33

Quote: Originally posted by Pyro  
melt it under oil, pour it into a long mold under oil, then you can cut off pieces with a knife.
how about a chisel?


I vote for this method. Properly set-up it should go without a hitch without any chance of loose particles of sodium flying about.

I used this method to cast weights using Wood's Alloy, due to its low melting point. Only after I ordered it did I recall that it contained cadmium, which is regulated 10 times more strictly than lead due to its even greater toxicity. SO I decided to metal and cast in under water, so that there would be possible fume release. It worked very well.

With such a large amount it justified building an apparatus for this purpose, a melt hopper and a submerged mold so that heat and gravity can do their work. You might even be able to run it batches, casting only part of the hopper load each time.

WGTR - 24-8-2014 at 17:10

Approaching this from another direction, what would you do if you had 25 lbs. of burning sodium? The chance this would happen is remote, given the proper precautions. However, one has to think not only if something will or won't happen, but also how badly your day would be ruined if it did happen.

In other words, it might not be wise to section this on your kitchen counter. Perhaps do it in a storage building away from the house, and away from anything flammable or valuable.

Generally, I'd recommend against melting the whole lot of it at once. 5 gallons of water can spread out pretty far on the floor. 5 gallons of molten sodium might not go quite as far, but...


Dr.Bob - 24-8-2014 at 17:49

I agree, try to do it outside, far away from your car and house. Have some containers of mineral oil ready to put the pieces into, otherwise they will quickly corrode or catch fire. Just cut through it somehow into pieces, trying to get pieces sized to fit into the containers. I think any old kitchen knife will do, the bigger the better. i would also have some sand around to put out the fire if it happens. Melting it is a very bad idea on that scale. It is pretty soft, so it should be able to be cut into pieces.


Pyro - 24-8-2014 at 18:47

a metal shop has these big presses, take it there and have it cut into manageable pieces.

OK, heres an idea:
get 2, 1/2 inch boards of plywood. one will be just something to protect the floor.
in the other one, make 2 parallel grooves (1inX1/2in) far enough apart that your Na will fit in between (if you Na is 10 inches, make the grooves 11 inches apart)
Next, get a long blade of some kind, embed it in the block of sodium. now put it (knife side down in the plain (non-grooved board)
Put your grooved board on top of the sodium. now place a line over each side of your blade (you may need to notch it so the line stays in place, 1/8 or 1/4 inch nylon should do fine).
find a +-1/2 inch round metal object (pipe or bar) and place it perpendicularly over both grooves.
now get 2 short lengths (approx 10 inches each) of something similar.

make a single loop around the bottom edge of the cutting instrument, the long metal bar and a short one, do this on each side, it doesn't have to be very tight.
once this has been done on both sides, get a friend to twist one, or twist both short bars yourself, this works as a Spanish windlass and will pull the cutting object towards the top plank.

This sounds complex, but it is actually very simple, uses what most people have lying around. you should be able to do it within an hour.
below is a rough diagram


twist twist
----------- -------------..................shorter pieces of pipe, bar,... that you actually twist
" "..........................the line here will start to twist, pulling the cutter up
--------------------------------------------------------........metal pipe, bar,...
==========================................plywood sheet with grooves
' NaNaNaNaNaNaNaNa '
' NaNaNaNaNaNaNaNa '
' NaNaNaNaNaNaNaNa '
' NaNaNaNaNaNaNaNa '
' NaNaNaNaNaNaNaNa '
' NaNaNaNaNaNaNaNa '..............................line connecting cutter with bar=', sodium=Na
/////////////////////////////////////...........................cutter
============================................bottom plywood piece

I hope that cleared things up

[Edited on 25-8-2014 by Pyro]

jamit - 25-8-2014 at 02:50

Quote: Originally posted by Dr.Bob  
I agree, try to do it outside, far away from your car and house. Have some containers of mineral oil ready to put the pieces into, otherwise they will quickly corrode or catch fire. Just cut through it somehow into pieces, trying to get pieces sized to fit into the containers. I think any old kitchen knife will do, the bigger the better. i would also have some sand around to put out the fire if it happens. Melting it is a very bad idea on that scale. It is pretty soft, so it should be able to be cut into pieces.



Thanks Bob. I'm going to attempt to cut the sodium this week.

MrHomeScientist - 25-8-2014 at 05:07

Theodore Gray has a page about his 'sodium party', where he throws big chunks of Na into a lake on his property: http://www.theodoregray.com/Periodictable/Stories/011.2/inde...

The second video in the list at the bottom shows how to cut large blocks of sodium: http://www.theodoregray.com/Periodictable/Stories/011.2/Vide...

I can't watch the video on my work computer because we are stuck in the stone age (IE), but I believe he uses a wooden chisel and a rubber mallet. Pretty simple, really. Take heed of Bob's advice as well.

unionised - 25-8-2014 at 08:14

I also can't see the vid (don't know why).
But the web page that points to it says
"Click here for a video showing how this lump was cut off of the main block: A wood chisel and some pushing is all it takes, because this stuff is very, very soft."


There's a difference between a wood chisel and a wooden chisel.

jamit - 25-8-2014 at 14:00

The video page does not work. but thank you "mrhomescientist" for the link -- for trying to help. I noticed on your Utube video that you've acquired some large amount of sodium too.

Leben - 25-8-2014 at 16:11

In case you are planning to do this outside..... be sure to check the weather forecast first.

jamit - 25-8-2014 at 18:18

Ok, I've finally opened the 5gallon can of sodium and discovered that it has been already cut into 2lb chunks, which is great, but it has already reacted with the air and formed a hard crust of sodium hydroxide. I don't know how deeply its encase in the sodium hydroxide. I'll have cut it open to find out. But here's picture of one of the chunks of sodium (15 chunks in total).

I can try cutting the edges off to expose the pure sodium or is there a way to clean it without cutting it. Can I clean it with xylene or toluene? Or is that inpractical? Any suggestions?



IMG_3402[1].JPG - 2.3MB

Oscilllator - 25-8-2014 at 18:52

I think at this point your best option is to melt the sodium. Scraping off the sodium hydroxide is likely to be difficult, ineffective and unsafe.
Because your sodium is in 2lb chunks, you could try melting it in a medium-sized metal container, then finding a way to draw off the sodium from the bottom of the container. You could use a syringe, but this would be painfully slow and besides, the sodium could well freeze in the syringe.

[Edited on 26-8-2014 by Oscilllator]

DrAldehyde - 25-8-2014 at 19:08

The 40's were a simpler time.

disposal of sodium, 1947: http://youtu.be/HY7mTCMvpEM

jamit - 25-8-2014 at 20:29

I actually had a chance to cut the sodium and the white crust is not too thick. It's not bad at all. I'm going to cut away all the white crust and divide the sodium chunks into 4 large pieces for storage in paraffin oil and mineral oil.

Now I can see that cleaning the sodium will leave behind lots of small pieces of sodium mixed with white crusted NaoH... What is the best way to clean that? Melting it? Or clean it with toluene or xylene?

gdflp - 26-8-2014 at 05:17

Melting those small pieces would be the best way to recover the sodium. If you just wanted to to destroy the sodium, try slowly adding it to an anhydrous alcohol and wait until the bubbling stops. Alternatively, get all of the pieces, melt them together, and throw them in a large pond.:D

MrHomeScientist - 26-8-2014 at 05:19

Quote: Originally posted by jamit  
The video page does not work. but thank you "mrhomescientist" for the link -- for trying to help. I noticed on your Utube video that you've acquired some large amount of sodium too.

Not nearly as large as yours! Mine was just one pound. It's so lightweight, though, that it takes up quite a bit of volume (as I'm sure you know by now). To cut mine up I just used a big kitchen knife and lots of mineral oil.

I think your best bet for cleaning up the 'cuttings' from cleaning the larger pieces is to melt it under oil and siphon it off with a syringe, since you'll have so much junk to get rid of. The clean sodium will sink to the bottom.

chemrox - 26-8-2014 at 10:02

Quote: Originally posted by Awesomeness  
First, get a bucket of dry xylene ready...

It'll be dry after the first chunk goes in hehehe

jamit - 26-8-2014 at 12:15

Here's my sodium in paraffin oil (large hdpe bottle and small jar) and the small mixture of sodium and sodium hydroxide in toluene. The sample in the toluene is much cleaner and shinier.

IMG_3415.JPG - 1.6MB
sodium in paraffin oil

IMG_3419.JPG - 1.9MB
sodium in toluene

IMG_3423.JPG - 1.8MB
sodium chunks in paraffin oil

jamit - 26-8-2014 at 23:12

Here's more picture.

image.jpg - 234kB

Sodium 2lbs!

Is anyone interested in buying some sodium? 1 lb for 100.00 includes shipping.

[Edited on 28-8-2014 by jamit]

Praxichys - 25-10-2014 at 11:32

I just bought 2lb from jamit and I must say that the service and communication was excellent. It was well-packed and shipped very fast.

Cutting it was not an issue:

https://www.youtube.com/watch?v=UsSnFEUDKtw&list=UUR3CEA...