Thread: Gas maker

They're no longer in use as calcium carbide is one of those hard to store chemicals - ie contact with water and it starts producing acetylene, which is flammable in concentrations between 3 and 97%.

I recall local plumbers and blacksmiths (in Germany) carting acetylene generator around with them to job sites when I was a kid. They were a single cylinder which contained water that could only reach the calcium carbide when the pressure dropped. Any gas generated lifted an internal floating cylinder and dispaced the water from the carbide container. So it was self-regulating. I believe it was a fairly safe device as they carted it about behind a pushbike in the early days and on the back of small trucks later on. They also had larger versions in the blacksmith shop.
It should not be difficult to build a small version for the hobby shop and the pressures in them are fairly low.

I have seen small units (couple of times bigger than a foot ball) used in Indonesia.
Will see if I can get some Pix next trip.

Any carbide device would not be considered stable by todays standards.

In the past carbide and the acetlyene made from it was used for all sorts of things.

Spelunkers ( cavers) used to use it ( as recently as the 70's)in their head lamps, some of the early vehicle lighting was carbide.

Carbide was the brightest portable lighting till the tilly lamp came along.

Banana farmers and some other friut growers used to use acetylene to force ripen the fruit........UM...that sort of activity would be frowned on these days.

Because some farmers had carbide in qualtity around the farm they often had acetylene generators and used it for welding.

I don't know how carbide would be regarded these days...it would certainly be considered dangerous goods.
I expect it to be a controlled substance.....I know of a number of far more inocuous chemicals that the police and national securty are keen to keep close tabs on.

I believe they still make Acetylene from carbide in some gas plants.


One device that IS most certainly in current use is hydrogen/oxygen generators..a very large proportion of the jewlery trade have gone across to them.

increasing control and high bottle rental have pretty well killed oxy acetylene among jewlers.

A bloke I knew was a jewlers apprentice back in the 80s.....he reconed it was comical that they had this pair of G sized bottles hooked up to a manafold supplying 4 blokes using these pissy little torches about the size of a biro.....nobody could remember when the cylinders where last filled.

I don't know how big these generators get or what sort of heat oxy hydrogen generates.

cheers

Originally Posted by soundman

I don't know how big these generators get or what sort of heat oxy hydrogen generates.

wikipedia says

Hydrogen-oxygen flame 2800°C
Oxygen-Acetylene flame 3300°C

Yes, a gas maker would be easy to make. A safe gas maker not so easy. A gas maker without Carbide, useless.
In the resurgence of biodiesel and fart collection for energy, one would think the gas maker would be a prime tool.

http://www.rexarc.com/images/pdf/mod...generators.pdf
This is a US manufacturer that sells to third world countries. Not economical in the US since there is a shortage of calcium carbide and it's use is anti economical.
Apparently there are Australian suppliers of calcium carbide, so it all comes down to how much it costs to make it.

Yeh it seems that carbide reactors are still used in the third world.

But there are definite dangers in the use of carbide.

As for the hydrogen...aparantly works well on aluminium, but causes hydrogen embrittlement in steel.

Biogas or methane..its pretty close to natural gas.
Not going to get there in the heat department for welding steel.

seems in the first world, the only viable alternative to acetylene is LPG, but not for welding steel.

cheers

Marc,

If you really want to make your own Acetylene using a Calcium Carbide gas generator, you could always go the whole hog with the DIY approach and make your own Calcium Carbide to start with.

http://www.ehow.com/how_6707402_make...m-carbide.html

I think that the above eHow article needs a few extra safety precautions added through:

1. Set up camp in the middle of the Simpson Desert so there's no one else around to get hurt when this Heath Robinson contraption goes bang.
2. Buy a few canaries to use as DIY gas detectors.
3. Update your will.

Seriously - I think you'll find it hard to buy the right sort of Calcium Carbide in Australia. The old Carbide Generators used for Oxy/Acetylene Welding, and the old Carbide Lamps, used Calcium Carbide in a pellet form or in some cases in a small block about the size of a match box. It's been a long time since I've seen some calcium carbide pellets, but I think the pellets I was shown were about 10mm diameter. I tried to buy some pellets a few years ago to get the Carbide Lamps working on an old boat that we were restoring.

The only calcium carbide I could buy in Australia was from chemical suppliers and came in powdered form. Every chemical salesman I spoke to said that the powdered calcium carbide was unsuitable for Carbide Lamps as the powdered calcium carbide degraded too quickly when it came into contact with water, with a violent reaction (how violent depends on how much you use), producing lots of acetylene very rapidly. Carbide Lamps used the pellets or small blocks as a way of reducing the surface area exposed to the water, and thus slowing down the gas production to a safe level. I did think about making my own pellets or small blocks from powdered calcium carbide, but I was never able to find out what substance was added to the calcium carbide in the old days to make it clump together into hard pellets or blocks.

Hope that info's useful.

Roy

Obviously BOC and Air Liquide are manufacturers of acetylene and in another time would have no problem selling carbide to you but I feel you will get the run around and you will be presented with all sorts of reasons why they can’t sell it to you .

Suppliers are such a risk averse lot and can be just that bit iffy about supplying any materials that could be converted into a gas with the capacity for a really big bang.



Bear in mind gas flow from and old time generator will not be the same as the gas from an acetylene cylinder which will store more volume and pressure as the gas is dissolved into acetone which is the reason you don’t lay a working cylinder down.
Somewhere though I saw a ( German ,I think)site that had new gas generators .They may have the acetylene dissolving into the acetone these days .I might be worth chasing.


There is reference in the link below to availability in 2008 of calcium carbide in sealed cans but if it was pricey then what price now?
Spielunkers link
http://www.wasg.org.au/lampfaq.html
Of course you will need a quite a bit for a generator.

Best of luck mate ,certainly an interesting thread.

Originally Posted by Marc

All this talking about renting cylinders, reminded me of a device panel beaters use to have to make acetylene gas.

Searching on google only shows ancient black and white pictures of this acetylene maker but nothing that says they are still available.
I know one could make it, but hei, who wants to muck around making that contraption. If it was available however, it is a consideration.

Are they banned? Gone? no longer economical? Does anyone know?
http://chestofbooks.com/home-improve...l#.VHA9ZleUemA

Here is an acetylene generator linkfrom Switzerland (not Germany as I thought)

http://www.gloor.ch/pdf/P122_en.pdf

Grahame

Possibly the best use of carbide was as a very effective fishing bait.
Take tin can, pierce a few small holes add carbide and seal lid. Throw or drop in the water and wait. Kerboom, all the little fishies float on up.

Local CQ legend has it that similar things occurred along the lines of placing a bit of carbide in a mudcrab hole.

The gas drives the crab out of the hole .

I am told it ruins the holes forever.I could not see the logic in that,as you have to get to the hole anyway and that's where all the work is.

Sticking a hook down the hole takes the same effort as placing the carbide-as our friends across the Pacific say- go figure?

Yeh, blowing up fish, poisoning water AND hooking crabs have all been illegal methods of fishing in every state in this country... like for EVer

IT is howeever completly legal to put ya arm into the crab hole and pull out em bare handed....that is considered " sporting"

cheers

Originally Posted by soundman

Yeh, blowing up fish, poisoning water AND hooking crabs have all been illegal methods of fishing in every state in this country... like for EVer

IT is howeever completly legal to put ya arm into the crab hole and pull out em bare handed....that is considered " sporting"

cheers

Very true.
There are still many that subscribe to the "illegal is a sick bird" train of thought. As such I doubt that " Winchester wobblers", spreading superphosphate in the water and carbide fishing will ever totally leave us.