Hello Forum!

Its been quite some time since my last post, but anyway...

I did a search in the Forum and could not find any reference, so i thought you might be interested in a few experiments i did with the metal Gallium.

It is not explosive, not even chemical, more physical but it is interesting, destructive and could be pretty useful in the modern Battlefield.

Gallium has a Melting Point of about 37C, but remains in Liquid State even below this temperature.
It is non-toxic and is not a regulatet substance, as far i know. I bought mine from Ebay, 15g about 20$.

Somewhere I read that Gallium corrodes aluminium pretty fast, and I wanted to test this.
Yes, its true. And it happens at an amazing speed and with amazing results.

I used a 10cm*15cm*1.5mm aluminium sheet made out of very strong aircraft aluminium for first experiments. I just made small scratch on the surface and rubbed some Gallium into that scratch. After a few minutes i could break the sheet with no effor at all, just like cardboard. Unbelieveable!!!
About an hour later, the aluminium to both sides of the crack was
very brittle in an about 1.5 cm broad area.

Next test object was a surplus aluminium heatsink with about 4mm thickness.
Again, I made a small scratch on the surface and rubbed some Gallium onto it.
I left it at the office, and when I returned there I could easily break the whole thing apart.
Last Experiment was a empty deodorant Can. I rubbed some Ga at the bottom. After 1 Hour i could easily poke through the bottom with a pencil.

As far as I could find out in literature, gallium is soaked into the aluminium along the crystal borders and thereby greatly lowering its strength.
Now I understand why gallium is not allowed to be transported on an Airplane (same as Mercury).

Conclusion:
Gallium is very well suited to desintegrate aluminium structures. It is non-toxic, odourless and silent.

Mercury does the same thing and if my memory serves me does it faster and better than galluim.

Yeah, the famous rusting bar...

http://www.popsci.com/popsci/how20/09550e0796b84010vgnvcm1000004eecbccdrcrd.html

While gallium is absorbed into the aluminium with no visble change in apperance, mercury forms an amalgam in which the Aluminium gets oxidized , eating through the aluminium quickly.
You can also induce this by coating it with with Mercury Cloride
solution.

The disadvantage is that Mercury and its fumes and saltes are poisonous.

If i find some Mercury , i will try this out..

If you had a business need you could purchase it, though it is a restricted item and the government tracks all purchases of this nature. They do this for lead compounds now days too :(

I bought mine from Ebay, 15g about 20$.

Also Gallium is pretty cheap compared to Mercury.
Mercury is as much as gold, I think.

I just tried Hg and Al it wasnt fast nor fantastic.
I scrached a 4mm Al plate alot and aplied a 7mm Dia Hg drop onto the scrached surface and went to smoko 45min later( jealous ;) ) there was a very small amount of Al oxide apparent on the Hg drop and the plate was still tough as it was before i started. my lab is 20 C and my mercury was redistilled liquid Hg

Yeah, the famous rusting bar...

The disadvantage is that Mercury and its fumes and saltes are poisonous.



Why is that a disadvantage? :D

The main uses of gallium are for high-temperature thermometers (enclosed in glasses with low coefficient of thermal expansion), due to its wide liquid range; and in gallium arsenide semiconductors for transistors (in which there is a very slight surplus or deficiency of Ga compared to As, to gve positive and negative semiconductors) and Ga-doped silicon and germanium semiconductors (in which a small amount of Ga produces p-type semiconductors). That reminds me: I wonder if Al has ever been tried instead of Ga (or In) in Si or Ge semiconductors as a dopant - it would be much cheaper than Ga, and its atomic size is much closer to that of Si than is that of Ga or In, resulting in less distortion of the crystal lattice; or if AlP (with a slight excess of either Al or P) has been tested for suitability as a semiconducting material.

I've always thought gallium would be an interesting assasins bullet, since it melts at human body temperature the body (dead or alive) would turn the bullet liquid, hence no rifling marks, if the bullet was found at all.

The question I have is, would the bullet completely deform when fired or would it simply "slick" the barrel with a thin layer or gallium? This of course would be a short range weapon.

If a gallium gun worked it could also be used for sabotague, just fire some gallium bullets at an aluminum target and the impact should cause enough impact damage to introduce gallium into the aluminums surface. The only problem seems to be keeping the gallium cool enough to remain solid before use. (Mabye Thermos makes a holster? :) )

This is a very interesting idea, and it may work if the gallium and the barrel are cooled enough. I could not find any information about how much heat is built up when a lead or copper jacketed bullet is fired, but I imagine that if you kept the bullet and the barrel cool enough, the gallium would not deform or melt too much. The problem of galliuming (equivalent of leading?) of the barrel would be potential incriminating evidence, and you would most likely want to rid yourself of the gallium impregnated barrel.

The problem of galliuming (equivalent of leading?) of the barrel would be potential incriminating evidence, and you would most likely want to rid yourself of the gallium impregnated barrel.

That could be kept to a minimum by using a sabot. It'd still likely be only good for one shot, though, since the one shot would heat up the barrel enough to allow the melting of the next round. Besides, heat differences in the barrel always provide inconsistancies in shot placement. Sight in by replacing your barrel into a cooler of dry ice between shots...

Interesting idea for a one shot kill, though. Keep 'em scratching their heads for awhile, anyway.

Frankly I am not addressing the use of gallium so much as I'm underlining the fact that "CSI" really is a TV show.....they mostly don't have anywhere near the resources that are displayed in the show.

There was a serious issue of tainted evidence and mishandling in one state that was the undoing of that state's police lab. One of the examples was a hand loaded 9mm bullet in a 357 revolver cartridge. the deformity of the bullet resulted in the idiots simply weighing the bullet, measuring the base and concluding that the weapon WAS a 9mm.

One of the most unfortunate misjudgments on the part of a perpetrator is the focus on the weapon. The action and witnessing of that action is the basic undoing of most all cases. Those which rely on material evidence are so shallow that the DA usually declines to proceed with prosecution.

So while gallium is a fun element, the use of unique materials is not the answer to the "perfect crime". Just the opposite: the gallium would be a focus of material evidence leading to a paper & people trail. And THAT would be the start of a long stay in a unique environment for someone focused on the object instead of witnesses and the like.

but it's not to make bullets out of.

1) The friction high temperature of the combustion gasses at the base form a liquid layer. This is unstable and uneven, and gets slung off the bullet in a random way by centrifugal force as it leaves the barrel. That leaves the bullet unballanced about it's long axis - and so it veeres off in some random direction. The same is true of bullets made of ice. A gas check helps a little, but not much. You might get an effective load made of ice buckshot, but I doubt it.

(Oak buckshot, on the other hand, is very useful in case of vampire attack)

2) It IS useful in taking casts of chambers, to find out exactly what diameter your lands and grooves are, if you're handloading for sub-minute of arc accuracy.

3) The presence - even at minute, sub-ppm levels - of gallium in your shop, home, rifle barrel, gun case, ammo case, car trunk, etc - would be proof beyond doubt that the mystery bullet came from you.

A quick thought. If you really wanted to use gallium bullets, you may be able to build/rebuild a high pressure pneumatic gun and use a rifled barrel for higher accuracy. If you used paintball CO2 tanks, the cooling down of the tank (caused by the conversion from liquid to gas) and gas being excreted would help a lot with keeping the gallium cool.

Another issue with gallium would be its density (5.91 g/cm³ vs lead's 11.34 g/cm³).

If gallium bullets wouldn't work with firearms then airguns could be a good alternatives.

Gallium pellets could be loaded with toxins, say ricin or arsenic (which we all know is made out our arse :) ), fire the pellet from the airgun into your target, (hopefully it will penetrate the clothing) and when it melts the target will be history.

The best two methods would be a high power pistol in a pocket and a hard bump against a target in a crowd and a high power air rifle in a car washington sniper style, I'd assume.

Oh and if the high power sniper method works well you could load the gallium pellets with psydelic compounds and spread the luv! :p

Someone mentioned CO2 paintball tanks... why not just pb guns? Take one pellet, extract ink with syringe, replace with molten gallium, top off with a little glue. Keep in a cool place (Small thermos with screw top). Useless for killing an individual, but, in the case of aircraft landing gear, or suchlike vulnerable chunks of aluminium, it could be a valuable destructive tool. If the mass of the metal, as opposed to relatively light ink, could be a problem, tweaking the valve of the gun could be a simple operation.