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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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Id like to know the differences in using these two fuels for normal
around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner "If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around." "Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion). -Buddy Jordan 2001 |
#2
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Try http://www.tinmantech.com/html/oxy-acetylene_torch.html
The tips will have to change. Probably need to locate a few suppliers nearby to see what the cost comparison will be. I do not know whether propylene tanks are sold vs. rented. When I looked into it, my supplier had only acquired rental tanks. If it's economy that you seek, why not just go get a propane tip and use that instead of acetylene? I started with propane, never welded with it, before I bought my acetylene bottle. Propane is everywhere, even on the weekends. The barbecue-size 20# tank will run for quite a while or 40# and 50# tanks are available as well. It's the oxygen that cuts anyway. The hose may need a change-out from acetylene-only hose to general fuel-gas hose which will run propane, NG, propylene as well as acetylene. Tom Gunner wrote in message . .. Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner "If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around." "Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion). -Buddy Jordan 2001 |
#3
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Propylene is not necessarily safer. If acetylene leaks, it will rise and in
most cases tend to disperse. Propylene, being heavier than air, will usually descend and travel to the lowest point and concentrate. If there is an ignition source, you will have a problem. You need to at least change cutting tips. Better yet, get an injector style mixer, too. Check out Harris You need to use grade T hoses, not the grade R hoses often used for acetylene. You can use acetylene regulators. You will use much more oxygen compared to acetylene because of the chemistry involved. Check you local supplier for price. |
#4
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![]() "Gunner" wrote in message ... Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner Gunner, My understanding is that propane is ok for cutting but not a hot enough flame for welding. Propane is cheaper per unit energy that acetylene here in the UK. Propane cutting nozzles are markedly different - here in the UK they are of a two part concentric construction, the outer being the same copper alloy used with acetylene, but the inner is a brass, and they come apart for cleaing . My personal opinion is that for general use acetylene is more versatile as you can weld as well, but I actually have both. Not sure if it is recommended, but I'm using an acetylene regulator on a propane tank for my metal melting furnace. Beware that propane needs a special hose, as it disolves the rubber used on acetylene hoses. AWEM |
#5
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Gunner was asking about propylene which is very similar to what we in
the UK refer to as MAPP gas, although that is a brand name. Propane is a different gas and commonly used for cutting due to lower costs but I think it doesn't necessarilly gives as good a result. Andrew Mawson wrote: "Gunner" wrote in message .. . Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner Gunner, My understanding is that propane is ok for cutting but not a hot enough flame for welding. Propane is cheaper per unit energy that acetylene here in the UK. Propane cutting nozzles are markedly different - here in the UK they are of a two part concentric construction, the outer being the same copper alloy used with acetylene, but the inner is a brass, and they come apart for cleaing . My personal opinion is that for general use acetylene is more versatile as you can weld as well, but I actually have both. Not sure if it is recommended, but I'm using an acetylene regulator on a propane tank for my metal melting furnace. Beware that propane needs a special hose, as it disolves the rubber used on acetylene hoses. AWEM |
#6
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![]() Gunner wrote: Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? I haven't done cutting, but I did not have to change anything for brazing. How much does a tank of propylene cost versus acetylene? I have a tank about the size of a small propane tank - I forget the description, but it is maybe 15 Lbs or so, about 2.5 gallon size, I think. It has lasted years, and I suspect there are a few more years left in it. It is supposed to cost $10 - 15 for a refill. Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? I'm sure of that, as the guy at the local gas supplier refitted my regulators for his tanks and said everything was OK. Jon |
#7
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I would make the jump directly to propane. The proprietry mixtures are
appropriate for naval codes or underground mines. You cannot weld with these gases with any quality so you are restricted to heating and flame cutting which propane will do anyway. The big plus is safety. Acetylene has a 2.5 to 82 percent flammable range. Propane is 2.1 to 9.5 and propylene is 2.4 to 11.1 Why pay a welding gas supplier top dollar when you can use a common and cheap fuel.??? Randy "Gunner" wrote in message ... Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner "If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around." "Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion). -Buddy Jordan 2001 |
#8
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This has opened up a whole new train of thought for me. I do all my welding
with stick and MIG, but I recently bought a used oxy/acet rig (without bottles) for limited cutting. So, it appears from this thread that I can get by with just purchasing an oxygen bottle, as I have several of the smaller propane bottles the size used in BBQs. Would you kind folks go over what I need to do to set up a propane cutting torch - will I be giving up any cutting ability using propane instead of acetylene? Thanks! John "Gunner" wrote in message ... Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner "If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around." "Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion). -Buddy Jordan 2001 |
#9
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Cutting with propane requires a different tip on the torch. That runs
around fifteen to twenty dollars.each. The flame is not a hot as acetylene so it takes a few seconds longer to preheat the edge of the plate. The cut is cleaner giving less slag hanging on the bottom of the plate. Also the height of the torch tip off the plate is not as critical. Most automatic cutting tables use propane or natural gas to burn plate because it is cleaner and more economical. Lighting propane is a learned skill. I often will lay the torch against the plate to prevent the flame from blowing out when I strike up. Yes you will use more oxygen but propane is so much cheaper and safer that you still save money . My acetylene regulator attaches directly to my small 20 pound bottle of propane. Randy "Doctor John" wrote in message ... This has opened up a whole new train of thought for me. I do all my welding with stick and MIG, but I recently bought a used oxy/acet rig (without bottles) for limited cutting. So, it appears from this thread that I can get by with just purchasing an oxygen bottle, as I have several of the smaller propane bottles the size used in BBQs. Would you kind folks go over what I need to do to set up a propane cutting torch - will I be giving up any cutting ability using propane instead of acetylene? Thanks! John "Gunner" wrote in message ... Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner "If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around." "Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion). -Buddy Jordan 2001 |
#10
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Gunner, I am about the most thrifty guy around or so I'm told ( by the way
thrifty does not mean cheap!). I have used propane for all my torch cutting for years. For the small amount of brazing or other oxy/acet work I have a small "B" tank on my torch cart hooked up to a small Harris torch, I use a "Y" connector on the oxygen tank with a separate valve for the Harris torch. My cutting set up is a Air Liquide with a two piece tip. Propane cuts beautifully and is readily available. Try it you will like it! Now don't get me wrong that you never want to weld with oxy/acet but we now have so many other affordable welding systems at hand that if you have stick, mig or Tig you will go for them first. In my opinion someone just starting out should look at Oxy /acet setups that they can convert later to use for propane when they move on to other equipment. I personally started out using oxy/acet over 30+ years ago on a field service crew welding take offs for new residential and commercial gas services , I didn't realize it then but all of those welds in the ditch taught me an awful lot about heat control and body contortion since we did all of the excavation with a shovel. Pete "Gunner" wrote in message ... Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner "If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around." "Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion). -Buddy Jordan 2001 |
#11
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For propane cutting, get as large an oxygen bottle as possible,
consistent with portability and cost considerations. It's oxygen that does the cutting anyway. A cutting tip recessed for propane is required in order to stay lit. The type T hoses should replace the acetylene-only type R hoses. Propane will take a little longer to heat the metal sufficient to start the cut, but once you are cutting, there's no difference since it's the oxygen that produces the cutting action. You may also need to adapt your bottle cart, since the O2 bottle is taller and slender while most propane tanks are short and larger in diameter. On Tue, 23 Nov 2004 20:32:01 -0700, "Doctor John" wrote: This has opened up a whole new train of thought for me. I do all my welding with stick and MIG, but I recently bought a used oxy/acet rig (without bottles) for limited cutting. So, it appears from this thread that I can get by with just purchasing an oxygen bottle, as I have several of the smaller propane bottles the size used in BBQs. Would you kind folks go over what I need to do to set up a propane cutting torch - will I be giving up any cutting ability using propane instead of acetylene? Thanks! John |
#12
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![]() Some interesting posts here. I have been interested in setting up for some brazing with propane but don't want the bother of oxygen tanks either. Anyone tried compressed air and propane? Is this feasible? It sounds like a standard oxy/acet torch will do brazing with propane and oxygen. Is that also true of propane and compressed air? Cheers Glenn "Gunner" wrote in message .. . Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner "If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around." "Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion). -Buddy Jordan 2001 Glenn Pure Canberra, Australia Web page: http://www.evans-pure.net |
#13
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Anybody use natural gas for cutting and heating? Seems like that might be the
most economical and convenient alternative. I have thought about tapping into the pipe supplying my shop furnace. Obviously keep the acetylene for gas welding. Any experience with a similar arrangement? Thanks, Mill Gunner, I am about the most thrifty guy around or so I'm told ( by the way thrifty does not mean cheap!). I have used propane for all my torch cutting for years. For the small amount of brazing or other oxy/acet work I have a small "B" tank on my torch cart hooked up to a small Harris torch, I use a "Y" connector on the oxygen tank with a separate valve for the Harris torch. My cutting set up is a Air Liquide with a two piece tip. Propane cuts beautifully and is readily available. Try it you will like it! Now don't get me wrong that you never want to weld with oxy/acet but we now have so many other affordable welding systems at hand that if you have stick, mig or Tig you will go for them first. In my opinion someone just starting out should look at Oxy /acet setups that they can convert later to use for propane when they move on to other equipment. I personally started out using oxy/acet over 30+ years ago on a field service crew welding take offs for new residential and commercial gas services , I didn't realize it then but all of those welds in the ditch taught me an awful lot about heat control and body contortion since we did all of the excavation with a shovel. Pete |
#14
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On Wed, 24 Nov 2004 11:18:51 GMT,
(Glenn Pure) wrote: Anyone tried compressed air and propane? Is this feasible? Years ago - it's very low pressure - a fan blower, not a piston compressor. OK for brazing, but not much else. I do all my hot stuff with oxy-propane these days, or use a friend's gas forge with a Ron Reil propane injector / natural draught burner. Blown air / gas seems to have arisen with mains gas, because that's all they had in those days. Then someone discovered the injector trick and made powerful (but large) burners that didn't need the air blower. Bottled oxygen was cheap (if you've already bought oxy-acetylene welding kit) and that took over for small burners or intense heating. The blower kit is still around, but it seems to have been marginalised. Here in the UK gas is "free" in comparison to our enormous cylinder rental costs (not propane, but certainly oxygen / acetylene). Once I've got the kit, then it costs me nothing extra to use it more. -- Smert' spamionam |
#15
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On Tue, 23 Nov 2004 19:22:31 +0000, David Billington
wrote: Gunner was asking about propylene which is very similar to what we in the UK refer to as MAPP gas, although that is a brand name. Why is it that here in the UK MAPP is still a rarity and using propylene as a fuel gas is unheard of ? Is it commonplace in the US? |
#16
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CNG is used in scrap metal yards to cut pieces to length. Big bulk
tank (only moved with a forklift or hoist) stays in one place while a very long supply hose allows the torch to reach several cutting areas nearby. It's still not as plentiful as propane tanks for barbecues and requires a different tip than propane or acetylene. I doubt that the gas pressure for NG supplied to homes and buildings will be sufficient, even on the supply side of the meter/regulator. On 24 Nov 2004 12:17:33 GMT, (MP Toolman) wrote: Anybody use natural gas for cutting and heating? Seems like that might be the most economical and convenient alternative. I have thought about tapping into the pipe supplying my shop furnace. Obviously keep the acetylene for gas welding. Any experience with a similar arrangement? Thanks, Mill |
#17
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In article , Andy Dingley
wrote: On Tue, 23 Nov 2004 19:22:31 +0000, David Billington wrote: Gunner was asking about propylene which is very similar to what we in the UK refer to as MAPP gas, although that is a brand name. Why is it that here in the UK MAPP is still a rarity and using propylene as a fuel gas is unheard of ? Is it commonplace in the US? MAPP is a mix of gasses. Methyl-Acetylene Poly-Propylene. It used to be more common in the US, but has been replaced by Propylene to a large degree. I prefer MAPP for heavy cutting, but it is difficult for a small shop to get the tanks. For the last 2 years I have been using a Propylene mix called Flamal, and it works very well for cutting, and heating. A mix I see a lot at professional flame cutting shops is called Chemtane II. Propane and Natural gas are also used a lot by larger cutting shops. |
#18
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Hi all,
Being a "hobbyist" with just enough knowledge to be dangerous, I have nothing to add to this discussion although I'm learning tons!!! I am curious about the term "cutting shop" Are these businesses that specialize in cutting metals or are they just big welding shops that also do a lot of cutting in their normal course of business??? Just curious as I had never heard the term used before. BTW Ernie...glad to see you posting more in the group. Finger getting better, I hope. Marc "Ernie Leimkuhler" wrote in message ... In article , Andy Dingley wrote: On Tue, 23 Nov 2004 19:22:31 +0000, David Billington wrote: Gunner was asking about propylene which is very similar to what we in the UK refer to as MAPP gas, although that is a brand name. Why is it that here in the UK MAPP is still a rarity and using propylene as a fuel gas is unheard of ? Is it commonplace in the US? MAPP is a mix of gasses. Methyl-Acetylene Poly-Propylene. It used to be more common in the US, but has been replaced by Propylene to a large degree. I prefer MAPP for heavy cutting, but it is difficult for a small shop to get the tanks. For the last 2 years I have been using a Propylene mix called Flamal, and it works very well for cutting, and heating. A mix I see a lot at professional flame cutting shops is called Chemtane II. Propane and Natural gas are also used a lot by larger cutting shops. |
#19
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On Tue, 23 Nov 2004 20:32:01 -0700, "Doctor John"
wrote: This has opened up a whole new train of thought for me. I do all my welding with stick and MIG, but I recently bought a used oxy/acet rig (without bottles) for limited cutting. So, it appears from this thread that I can get by with just purchasing an oxygen bottle, as I have several of the smaller propane bottles the size used in BBQs. Would you kind folks go over what I need to do to set up a propane cutting torch - will I be giving up any cutting ability using propane instead of acetylene? Thanks! Forget about oxygen too. You DO have an air compressor, right?? Propane Air works good for cutting - most of the scrapyards here abouts use it. John "Gunner" wrote in message .. . Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner "If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around." "Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion). -Buddy Jordan 2001 |
#20
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In article et,
mjones wrote: Hi all, Being a "hobbyist" with just enough knowledge to be dangerous, I have nothing to add to this discussion although I'm learning tons!!! I am curious about the term "cutting shop" Are these businesses that specialize in cutting metals or are they just big welding shops that also do a lot of cutting in their normal course of business??? Just curious as I had never heard the term used before. Burning shops do nothing but oxy-fuelgas cutting of heavy steel. Every major city has at least one. The older shops use electric eye pantographs to follow a line drawing. The newer shops are all CAD-CAM. A lot of them have added laser, plasma and waterjet tables to augment their burning tables, but oxy-fuelgas is still the cheapest way to cut heavy steel. The other processes are better for aluminum, stainless steel and sheet metal. BTW Ernie...glad to see you posting more in the group. Finger getting better, I hope. Marc Monday night at school, I laid my first decent TIG welds since the accident 10 weeks ago. Tuesday I went in for revision surgery and nail ablation. Full general anesthesia is not my idea of fun. 3 hours dissapeared, no dreams, and then 2 hours of trying to get my eyes to focus, and another hour trying to remeber how to walk. My right hand is back to a big bundle of gauze bandages. They removed the vestigial fingernail, and reshaped both finger tips. Oxycodone takes the edge off the pain. "Ernie Leimkuhler" wrote in message ... In article , Andy Dingley wrote: On Tue, 23 Nov 2004 19:22:31 +0000, David Billington wrote: Gunner was asking about propylene which is very similar to what we in the UK refer to as MAPP gas, although that is a brand name. Why is it that here in the UK MAPP is still a rarity and using propylene as a fuel gas is unheard of ? Is it commonplace in the US? MAPP is a mix of gasses. Methyl-Acetylene Poly-Propylene. It used to be more common in the US, but has been replaced by Propylene to a large degree. I prefer MAPP for heavy cutting, but it is difficult for a small shop to get the tanks. For the last 2 years I have been using a Propylene mix called Flamal, and it works very well for cutting, and heating. A mix I see a lot at professional flame cutting shops is called Chemtane II. Propane and Natural gas are also used a lot by larger cutting shops. |
#21
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I did a Google search for propane- compressed air metal cutting and only
found products for soldering and brazing. One site has info indicating that propane/air will reach 2000 deg. C and propane/Ox will reach 2800 deg. I'd love to just use my shop air compressor and left over propane tanks to cut metal (max soft steel thickness to be cut would probably be less than an inch). Can you give me any more info or links to find cutting torches using propane and compressed air? Thanks John wrote in message ... On Tue, 23 Nov 2004 20:32:01 -0700, "Doctor John" wrote: This has opened up a whole new train of thought for me. I do all my welding with stick and MIG, but I recently bought a used oxy/acet rig (without bottles) for limited cutting. So, it appears from this thread that I can get by with just purchasing an oxygen bottle, as I have several of the smaller propane bottles the size used in BBQs. Would you kind folks go over what I need to do to set up a propane cutting torch - will I be giving up any cutting ability using propane instead of acetylene? Thanks! Forget about oxygen too. You DO have an air compressor, right?? Propane Air works good for cutting - most of the scrapyards here abouts use it. John "Gunner" wrote in message .. . Id like to know the differences in using these two fuels for normal around the farm cutting and brazing. I understand that propylene is safer, has more in the tank, is cheaper..and thats all I know. Ive got an old S/V 100 torch handle and various cutting heads and brazing tips, as well as an old Union Carbide cutting torch. I have to change the cutting tips, correct? What about the existing brazing tips? How much does a tank of propylene cost versus acetylene? Is there an issue with my hoses? Regulators? Can a acetylene regulator be used for propylene? In the past, an acetylene tank has lasted me a couple years, but Ive sorta gotten the welding bug and Im doing all sorts of projects now. Ive got tig/stick welders to weld with, but will be doing some brazing and silversoldering (band saw blades, brazing cast iron..the usual) Any good links to any good information or some hints and tips? Tanks G Gunner "If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around." "Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion). -Buddy Jordan 2001 |
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On Wed, 24 Nov 2004 09:12:38 -0400, "jtaylor"
wrote: "Glenn Pure" wrote in message ... Some interesting posts here. I have been interested in setting up for some brazing with propane but don't want the bother of oxygen tanks either. Anyone tried compressed air and propane? Is this feasible? It sounds like a standard oxy/acet torch will do brazing with propane and oxygen. Is that also true of propane and compressed air? You can braze small parts with porpane/air and a "swirl-torch" - it has a gizmo in the torch after the venturi that creates a vortex and makes more heat. Noisy, and the propane bottle a) gets cold b) doesn't last very long, but it works, and the torch is cheap, and you can carry it around in a backpack with all the orher tools you might need to fix something 8 miles out in the woods. I have two of these hooked to bbq tanks with extension hose. They work great when I need a good quantity of heat. One set cost me about $30 when they first became available, the other cost $2 on a saturday saleing expedition a couple years ago. Gerry :-)} London, Canada |
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I've been using oxy-propylene for a few months now--here's what I've
learned... I have to change the cutting tips, correct? What about the existing brazing tips? I found you can use standard acetylene tips for brazing, but they need to be *much* larger. I am using a drilled-out #4 to do brazing on 1/8" to 1/4" steel (forgot how big... just kept drilling till it heated fast enough... I can check if helpful). The little tips blow out very easily, and the big ones will, too, if I try to braze close into a 3 sided inside corner, or i/s a tube. I am told if you countersink the orifice .060 or so it helps keep the flame on the tip. Also, to get enough heat the torch will hiss loudly. The flame is not real precise like w/ acetylene, but for most brazing it is fine. I had no success using an acetylene cutting tip--wouldn't stay lit--but I think others have done it. I bought a 2 pc. #1 fuel gas cutting tip and it lights and cuts great. Like others said, use "T" hoses (which happen to be std on Victor equipment, I found). Acetylene regulators are fine, unless you are doing really serious cutting where you might need more than 15psi. The flux that seemed to be most recommended was Gasflux Type B "Blue Paste": http://www.gasflux.com/paste.html The only authority I could find on flame adjustment is here (for MAPP): http://www.machinist.org/army_welding/Ch11.htm See Figure 11-3 and the text below. Good luck! David (from the link ![]() 1. A carburizing flame looks much the same with MAPP gas or acetylene. It has a yellow feather on the end of the primary cone. Carburizing flames are obtained with MAPP gas when oxyfuel ratios are around 2.2:1 or lower. Slightly carburizing or "reducing" flames are used to weld or braze easily oxidized alloys such as aluminum. 2. As oxygen is increased, or the fuel is turned down, the carburizing feather pulls off and disappears. When the feather disappears, the oxyfuel ratio is about 2.3:1. The inner flame is a very deep blue. This is the neutral MAPP gas flame for welding, shown in figure 11-3. The flame remains neutral up to about 2.5:1 oxygen-to-fuel ratio. 3. Increasing the oxygen flame produces a lighter blue flame, a longer inner cone, and a louder burning sound. This is an oxidizing MAPP gas flare. An operator experience with acetylene will immediately adjust the MAPP gas flame to look like the short, intense blue flame typical of the neutral acetylene flame setting. What will be produced, however, is a typical oxidizing MAPP gas flame. With certain exceptions such as welding or brazing copper and copper alloys, an oxidizing flame is the worst possible flame setting, whatever the fuel gas used. The neutral flame is the principle setting for welding or brazing steel. A neutral MAPP gas flame has a primary flame cone abut 1-1/2 to 2 times as long as the primary acetylene flame cone. |
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On Wed, 24 Nov 2004 22:47:02 -0600, "Tim Williams"
wrote: Propane and air, at atmospheric pressure, will certainly get you there but you need to confine the heat. No, that's not it. Steel isn't cut by "propane and oxygen", or even "acetylene and oxygen". The fuel gas is just there to heat the steel to ignition temperature, the actual cut is done by a reaction between pure oxygen and steel. If you do try and cut with just heat rather than oxidation, you'll find the kerf fills with molten iron slag anyway. In a big cut and a thermic lance, you can even take the heating torch away and run with a pure oxygen feed to a pure steel flame. Air is only 21% oxygen, which isn't enough to cut steel by burning it. If you tried you'd also have an excess of notrogen in there which would be "robbing" the oxygen and contributing little heat. You can't even fix this by using high-pressure compressed air. -- Smert' spamionam |
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A properly-adjusted oxy-acetylene flame has a "reducing region"
comprised primarily of CO that keeps the molten metal from oxydizing. An oxy-propane flame doesn't seem to have this, or at least it isn't as well defined. It can melt steel, but you get a porous mess rather than a sound weld. There used to be a hobby torch called "Solidox" that burned pellets to provide oxygen. They brazed OK but were worthless for welding. On Wed, 24 Nov 2004 22:47:02 -0600, "Tim Williams" wrote: "Doctor John" wrote in message ... I did a Google search for propane- compressed air metal cutting and only found products for soldering and brazing. One site has info indicating that propane/air will reach 2000 deg. C and propane/Ox will reach 2800 deg. Propane and air, at atmospheric pressure, will certainly get you there but you need to confine the heat. And that's rather useless unless you want to burn a few tanks making a *very* wide, *very* sloppy, *very* well fused weld on a few pieces of steel. ;-) I imagine it would have more gusto if you mixed it at high pressure behind a nozzle, say 15 or 30PSI. I know I've heard of oxypropane for cutting (and anything else like brazing), but not welding. Matter of fact, can someone explain why? Tim |
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On Thu, 25 Nov 2004 11:50:45 -0600, "Tim Williams"
wrote: http://www.reil1.net/Furnace.shtml So what ? Reil's burners don't use oxygen and they get hot. What's your point ? They still won't cut steel, no matter how hot you get it. You don't cut steel by _melting_ it out of the way. |
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