- Thread starter cazl1994
- Start date
chunkolini
celebrity artiste
- Messages
- 9,581
- Location
- Swansea
You can get disposable bottles of oxy/propane and other fuel gasses.
You cant get Acetylene in small disposables as it comes disolved in stuff*, that disolvey stuff (had a sudden blank)and soaked into a substrate. Compress it into a bottle and you have an instant bomb.
Apologies for the blank out. I will remember in 30 seconds after I leave this thread.
*Acetone that's the stuff. I always wonder how many people got blown to bits researching that one.
Here is a link to a portable kit, I fancy buying mysefl a set but as I have acetylene I cant think of an excuse. But I still want some.
http://www.thewelderswarehouse.com/Welding/Home_Plus_Portapack_Kit.html
Chunko'.
You cant get Acetylene in small disposables as it comes disolved in stuff*, that disolvey stuff (had a sudden blank)and soaked into a substrate. Compress it into a bottle and you have an instant bomb.
Apologies for the blank out. I will remember in 30 seconds after I leave this thread.
*Acetone that's the stuff. I always wonder how many people got blown to bits researching that one.
Here is a link to a portable kit, I fancy buying mysefl a set but as I have acetylene I cant think of an excuse. But I still want some.
http://www.thewelderswarehouse.com/Welding/Home_Plus_Portapack_Kit.html
Chunko'.
Omniata
Member
- Messages
- 3,191
- Location
- UK
The fuel gas on those portables is MAPP with other additives...
It's Methyl-acetylene and Propadiene, with other LPG's...
Good for thin stuff if you move quickly, difficult for anything above 1.5mm...
The heat with a Oxy-MAPP flame is much higher in the outer cone than acetylene so the area around the area your trying to weld heats up an awful lot quicker and to a higher temperature...
It's Methyl-acetylene and Propadiene, with other LPG's...
Good for thin stuff if you move quickly, difficult for anything above 1.5mm...
The heat with a Oxy-MAPP flame is much higher in the outer cone than acetylene so the area around the area your trying to weld heats up an awful lot quicker and to a higher temperature...
chunkolini
celebrity artiste
- Messages
- 9,581
- Location
- Swansea
Jay
As I signed off I remembered the name of the. disolvey stuff.
But how many people got mashed discovering that you can disolve acetylene in acetone and keep it soaked into a kapok (there is aore modern substitute) substrate without being blown to bits.
I may have to start a thread on this subject, there will be somebody here who knows this sytuff.
Chunko'.
As I signed off I remembered the name of the. disolvey stuff.
But how many people got mashed discovering that you can disolve acetylene in acetone and keep it soaked into a kapok (there is aore modern substitute) substrate without being blown to bits.
I may have to start a thread on this subject, there will be somebody here who knows this sytuff.
Chunko'.
Omniata
Member
- Messages
- 3,191
- Location
- UK
Kaolite, looks like pumice stone, very porous...
It dissolves in acetone very well, similar to CO2 in water...
Unfortunately it becomes unstable at high pressure so the kaolite clay is used as a "moderator"...
Most acetylene cylinders have a max fill pressure of 35psi, the rest less not more...
In gaseous form at any pressure above 15psi acetylene can/will spontaneously decompose to carbon and hydrogen gas, exerting enough pressure and heat to ignite in doing so...
Unfortunately for the small disposable cylinders there isn't enough room to hold both the clay matrix and enough acetylene to make them viable in terms of cost, nor safe in terms of shipping and manual handling!!!
Hence the use of acetylene derivatives which can be liquefied without nearly as much caution...
MAPP gas, an almost equal mix of methyl-acetylene and propadiene , as said, lives in a "symbiotic" relationship, as one changes to the other the other changes back...
This adds to it's stability, as stated in other threads this leads to it's preferred use in Europe, mainly Germany, whereby a full W sized cylinder can be filled with the mix at greater than 35psi, whereas with acetylene the cylinder wouldn't come close to being half filled when the clay and acetone are taken into account...
chunkolini
celebrity artiste
- Messages
- 9,581
- Location
- Swansea
Quality information as usual.
Omniata
Member
- Messages
- 3,191
- Location
- UK
Edmund Davy can be attributed to discovering it...
A member of the "Davy" family responsible for a number of fundamental discoveries in science at the time, including the Davy lamp...
Not too sure on who or how many were involved in its dissolution into acetone, I'll keep looking
Edit: Apologies if the threads being taken off topic...
thanks for the info guys.
a retierd man near me saw one we'd borrowed and wanted to know what it would do and where he could get one an chunko's link has given me the info
i needed because we only borrowed it for some lead burning.
once again answerd my question
thanks
caz.
a retierd man near me saw one we'd borrowed and wanted to know what it would do and where he could get one an chunko's link has given me the info
i needed because we only borrowed it for some lead burning.
once again answerd my question
thanks
caz.
shenion
Tool Pack Rat
- Messages
- 7,586
- Location
- Stone Mountain, GA USA
I had a Sears/Burnszamatic MAPP/Oxy setup.
You could braze with it. It worked on small stuff. I used it to braze cracked flanges on my bike exhaust.
It was expensive to use. The MAPP (or propane) tanks were not bad but the oxy tank was 1.1cf. Lasted about 10 minutes. At the time they were $6/ea, now about $15. Gets real expensive.
I now use a regular O/A torch with propane. Much cheaper as I use a refillable oxy tank (no rental) and a BBQ propane tank.
You could braze with it. It worked on small stuff. I used it to braze cracked flanges on my bike exhaust.
It was expensive to use. The MAPP (or propane) tanks were not bad but the oxy tank was 1.1cf. Lasted about 10 minutes. At the time they were $6/ea, now about $15. Gets real expensive.
I now use a regular O/A torch with propane. Much cheaper as I use a refillable oxy tank (no rental) and a BBQ propane tank.
chunkolini
celebrity artiste
- Messages
- 9,581
- Location
- Swansea
Yet again quality information.
But what experimentation was involved in finnding the rght solvent and conditions.
This is why I like this website so much.
Chunko'.
But what experimentation was involved in finnding the rght solvent and conditions.
This is why I like this website so much.
Chunko'.
I retired many years ago but when I first started work, in a ship yard, we had no acetylene cylinders and we had to generate our own.
At the time there was two types, water to carbide and carbide to water.
As the name indicates, in the first one water was dripped onto the carbide under controlled conditions in a sealed container and the acetylene gas produced drawn off direct to the cutting or welding torch via " flash back arrestor" ( not the type we use now ).
With this type of generator the max. pressure, allowed by law, was 3 lbs p.s.i. Using 15ft long hoses resulted in hardly any gas reaching the torch.
A special torch was developed known as a "divergent convergent torch" based on the principle that the Oxygen sucked the gas into a mixing chamber, within the torch, and then out to the nozzle. This method could only supply gas for one torch so for use in the workshop, were a number of torches needed to be used, the carbide to water was used.
In this generator the carbide was dropped into a container of water, again under controlled conditions, but because the heat produced was dissipated through the water, these could work at pressures of up to 5 lbs p.s.i.
No pressure above that was permitted without a home office certificate.
If I remember right the carbide to water generators are still used to produce the acetylene today but dissolved in cylinders containing a porous substance soaked in acetone , which can hold 25 times its own volume of gas. hence the very heavy cylinders.
This is the reason why acetylene cylinders must all ways be used in the up-right position or the acetone would enter the pipe line.
Hope that this of some interest to you all.
At the time there was two types, water to carbide and carbide to water.
As the name indicates, in the first one water was dripped onto the carbide under controlled conditions in a sealed container and the acetylene gas produced drawn off direct to the cutting or welding torch via " flash back arrestor" ( not the type we use now ).
With this type of generator the max. pressure, allowed by law, was 3 lbs p.s.i. Using 15ft long hoses resulted in hardly any gas reaching the torch.
A special torch was developed known as a "divergent convergent torch" based on the principle that the Oxygen sucked the gas into a mixing chamber, within the torch, and then out to the nozzle. This method could only supply gas for one torch so for use in the workshop, were a number of torches needed to be used, the carbide to water was used.
In this generator the carbide was dropped into a container of water, again under controlled conditions, but because the heat produced was dissipated through the water, these could work at pressures of up to 5 lbs p.s.i.
No pressure above that was permitted without a home office certificate.
If I remember right the carbide to water generators are still used to produce the acetylene today but dissolved in cylinders containing a porous substance soaked in acetone , which can hold 25 times its own volume of gas. hence the very heavy cylinders.
This is the reason why acetylene cylinders must all ways be used in the up-right position or the acetone would enter the pipe line.
Hope that this of some interest to you all.
Omniata
Member
- Messages
- 3,191
- Location
- UK
I may have to start another thread to compliment the info here, give me a day or two and I'll get a rattle on
I may have to ask for a section, "materials information" if you will, to document all the theory and practical associated with welding
gerry3: The carbide to water generators are still used today, there's two I think, joint owned by BOC and Linde in the UK that produce +80% of the acetylene used here, bottled or otherwise... They are really BIG and remote...
Give me chance and I'll type it up , I did get a lot of info from manufacturers and otherwise sometime ago whilst researching, I'm a chemist by background and acetylene has many other uses besides welding
I may have to ask for a section, "materials information" if you will, to document all the theory and practical associated with welding
gerry3: The carbide to water generators are still used today, there's two I think, joint owned by BOC and Linde in the UK that produce +80% of the acetylene used here, bottled or otherwise... They are really BIG and remote...
Give me chance and I'll type it up
, I did get a lot of info from manufacturers and otherwise sometime ago whilst researching, I'm a chemist by background and acetylene has many other uses besides welding 