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I have a new O/A cutting set up. A rather cheap one.... but its what I got. Have not got tanks yet. I keep running across post in various places that mention Propane instead of O/A cutting. I can't seem to find any good threads for more detail on this. What do ya'll know about using propane. For example.... you have to change tips, are these available at welding supply place?Cuts just as good as O/A?Uses Oxy along with LP just like O/A setups?Cuts better, worse or same as O/A?Cheaper or more $$$?One is easier to learn to cut with? Which?trying to decide which way to go before I go buy/lease tanks.etc etc etc.
Reply:You do need propane tips, your welding supplier SHOULD have them, if he stocks your brand of torch. You need a T-grade hose, or the propane will corrode it. Most cheap hoses are not T-grade. But some are.It cuts well, just a little longer for the preheat. Since the oxygen is what does the cutting anyway, that part is the same. It does use more oxygen for the same heating flame, too.I don't use my torch all that often, so even though I have a dozen propane cylinders (my house is propane), I still use acetylene for ALL my torch work.
Reply:CoachI use both propane and acetylene. I like propane for cutting and heating, though it does not beat acetylene. It is much cheaper to purchase than acetylene. I haven't noticed any accelerated use of oxygen, as some people suggest-- though I haven't done any indept studies either.I don't cut over 1/2" thick, a chore for my size0 propane tip. Rusty metal present more changes for propane, than acetylene.A 20 lbs propane grill last a long time. Make sure your tank is refillable and it is really cheap. The Blue Rhino brand tank used to not be refillable(without a special tool)-avoid them.Propane burns clean, no soot.Lighting a propane torch is diffenent than lighting a acetylene torch. Windy days cause difficult lighting propane torch.Can't weld steel with propane. Occasional o/a welding is the reason I have acetylene.
Reply:propane/oxygen with a rosebud tip will heat up anything way faster than acetylene any dayi got both and use both everydayi dont gas weld so to speak but you want big heat in a hurry then propane is the way to goand you dont have the black parachutes raining down on anything when starting the flame... ...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:You must not have very big acetylene heating tips. Acetylene heats way faster and that is why it is the prefered gas for most torch work. Acetylene is frowned upon by the EPA and propane is way cheap and much safer. Propylene is also prefered by the EPA and safer than acetylene. You don't have the problem of it becoming dangerously unstable above 30 psi. For cutting, the drawbacks to propane and propylene are increased heat into the work due to longer preheat periods. Propane requires special tips, propylene does not. Propane and propylene have a narrower range of air/fuel ratios over which it can burn. That makes it a pain to light your torch. If you open the O2 valve too fast, it blows the flame out.
Reply:Propane gives a much superior cut. To light propane open the propane fuel valve about half a turn then lay the side of the torch tip against your steel table or whatever. When you use your striker the flame will more easily chase back to the tip and establish itself. Lighting a propane torch while holding it in the air is very frustrating.
Reply:Originally Posted by 76GMC1500 Acetylene is frowned upon by the EPA and propane is way cheap and much safer. Propylene is also prefered by the EPA and safer than acetylene.
Reply:Originally Posted by lotechmanPropane gives a much superior cut.
Reply:The temperature of the propane flame is lower than acetylene. You only need to get the steel up to kindling temperature. With acetylene the flame is much hotter and the plate is more easily melted creating slag hanging to the bottom edge of the plate. Propane cutting torches allow a considerable variation in height and you can still maintain the cut. If your acetylene preheat flame tips get a quarter inch above the surface you risk losing the cut. This is a concern when cutting with multiple heads and the plate lifting with the heat of the cuts. The extra latitiude of propane helps. I have never seen a burning table using anything but propane or natural gas for flame cutting steel plate. If one was using a six head burning table one would need a bank of acetyene tanks to draw the fuel off at a safe rate. When you are cutting with propane and everything is dialed in it sounds like you are running a plasma. Today I was cutting half inch plate on our table with regular propane as we always use. When fitting I was able to stand the half inch plates up on edge. This is common with propane fueled cuts. I am amazed that you have even seen an automatic table running acetylene! I have never seen one running acetylene. It must be the geographic region you frequent. Different folks. Different strokes. Originally Posted by MAC702Is that why all the pre-plasma and modern CNC tables all use acetylene, of the ones that I've seen (lots)?I can't say you're wrong because I've never cut with propane. But why do you say it's a "much superior cut?"You've piqued my curiosity...
Reply:Originally Posted by lotechman I have never seen a burning table using anything but propane or natural gas for flame cutting steel plate. If one was using a six head burning table one would need a bank of acetyene tanks to draw the fuel off at a safe rate. When you are cutting with propane and everything is dialed in it sounds like you are running a plasma. I am amazed that you have even seen an automatic table running acetylene! I have never seen one running acetylene. It must be the geographic region you frequent. Different folks. Different strokes.
Reply:Here is an example of a propane fueled unit. In western Canada burning tables are all fueled by natural gas taken off the service line before pressure reduction or more commonly propane. From my experience in shops in the area hand torch use is about fifty-fifty between acetylene and fuel gas. Possibly the abundance of propane and natural gas is the reason?? The attached picture is an example of a shop I worked in about five years ago. The liquid oxy was delivered by tank truck weekly. Imagine trying to fuel such a unit with acetylene. You would have to have banks and banks of acetylene tanks and be changing then several times a day. A huge acetetylene tank weighing almost 200 pounds only has around 20 pounds of actual gas in it. Attached Images
Reply:How ironic, the U.S. acetylene producers buy calcium carbide from Canadian companies.I switched to propane a couples of years ago because there was a shortage of acetylene. I was told by local distributors, some company in Canada had had a fire and they were not able to ship Calcium Carbide. Here acetylene seems to be more popular for cutting. Even when I was in technical school they used strictly acetylene. Also, my steel distributor uses acetylene. They actually use plasma up to a certain thickness then gas above that thickness. I think there cut off is 1/2 in.Again, I like propane I also use it for my forge, hence it is more versitile around my shop. Only negative the tanks are awkward and inconvient if you have a cart made to carry a acetylene tank. Propane tanks don't really as cool on a truck as acetylene tanks.
Reply:Lotechman : i used to operate a similar machine that your pic shows. I was lucky , only 5 torches on mine . it too, used propane. The Navy had done many studies on overall cost , propane won out . we had a 750 gallon propane tank , & a 2000 gallon liquid oxygen tank piped into the shop. Ox tank on east side of shop , propane on west side , there was about 500 feetdistance between them (for safety) . before they had liquid ox, & propane they DID have huge banks of gasses , with several guys working full time changing them out . when i first saw the banks , i got tired just looking at the huge manifold system . (it was in active , thank GOD ! )
Reply:Originally Posted by lotechmanHere is an example of a propane fueled unit. In western Canada burning tables are all fueled by natural gas taken off the service line before pressure reduction or more commonly propane. From my experience in shops in the area hand torch use is about fifty-fifty between acetylene and fuel gas. Possibly the abundance of propane and natural gas is the reason?? The attached picture is an example of a shop I worked in about five years ago. The liquid oxy was delivered by tank truck weekly. Imagine trying to fuel such a unit with acetylene. You would have to have banks and banks of acetylene tanks and be changing then several times a day. A huge acetetylene tank weighing almost 200 pounds only has around 20 pounds of actual gas in it.
Reply:Until fifteen years ago I was in the Okanagan Valley. Now in the Surrey/Fraser Valley area according to the shop and work situations.
Reply:Okanagan valley stinks like a skunk's spray for work IF it Catches...Let it Burn
Reply:Originally Posted by gnm109I don't doubt your statement that the EPA frowns upon acetylene. Is there anything upon which they do not frown? If the EPA contiinues on the path that they have chosen, they will eventually shut down the welding industry. This is true since almost any item used in welding, from a striker to a bottle of helium, could be considered dangerous in the wrong hands. Their strict regulations (federal and state) have increased the price of welding equipment, gases and other consumables and non-consumables by more than 25% in the past 5 years. I don't feel any safer, do you? As far as I can tell, the job of the EPA is mainly to increase costs in industry as much as possible while still looking like they are dong something useful. They are noted for "throwing the baby out with the bath water". A good example is the paintng industry. Materials for painting a motorcycle used to be available for under $100 for the whole job. Now, it's not uncommon to pay more than $1,000 for materials sufficient to do the same job that are difficult to use, can't be stored after mixing and which require entirely new equipment. Thiis is apparently the EPA's method of forcing the little guy out of the business. Score one for the EPA. What's next?
Reply:My experience with welding, cutting, and forging, is that propane is best for spreading heat in a forging operation and that (hands down) acetylene is best for cutting and welding. Ive been taught that acetylene produces a very focused heat perfect for cutting and propane heat is more of a spreading heat that is much more suitable to heat a large section say for bending or forging. If you are cutting I would go for acetylene, the only (large) drawback being the price; and if you are heating go for propane. I have an oxy gas rig of both gases one for both (and very different) applications. This is just my personal experience between a welders and a blacksmiths world and what I was taught. Growing up in a western US (Rock Mountains) shop, acetylene was all that was used for cutting.
Reply:I have to agree with ZAP, on my oxy-acetilene classes i was told that the propane gives away more heat, however not as concentrated as oxy-acetilene. But since when you are cutting you are using a rosebud and getting the metal to red hot, propane gets it hotter faster. However I dunno about which cuts better, I was just told that propane is more dangerous than acetilene.
Reply:Basically, you have 4 choices of fuel for cutting with O2: Acetylene, Natural Gas, Propane and MAPP(methylacetylene-propadiene). Some of the benefits/challenges of each are as follows:ACETYLENE - When mixed with O2, generates the highest flame temperature3480deg.C(6300deg.F). This allows for fast starts when cutting. The O2 requirement for a neutral flame is 1 to 1(i.e., less O2 used than the other processes). Another benefit is the ability to weld/braze with this combination. The Oxy-A mix, however, gives the least desirable cut. As well, acetylene is an extremely unstable gas.NATURAL GAS - Flame temp. when mixed with O2 is 2540deg.C(4600deg.F). Most beneficial in conditions where it can be piped in. O2 requirement for neutral flame is 2 to 1. preheat & cutting speeds are slow. injector torch is required. This mixture is normally used in shops due to being relatively inexpensive.PROPANE - Flame temp. w/O2 is 2540deg.C(4600deg.F). O2 requirement for neutral flame is 4.5 to 1. Propane produces clean cuts & is relatively inexpensive. Due to the enormous amount of O2 required, specialized tips & a high quality mixing chamber(heavy duty) are necessary.MAPP - Forget the big words, MAPP is a mixture of acetylene & propane molecules. Flame temp. when mixed with O2 is 2900deg.C(5300deg.F). The O2requirement for a neutral flame is 2.5 to 1. Cuts are slower than acetylene & cleaner. MAPP is stored in liquid form, under high pressure. 1 MAPP cylinder equals 5 acetylene cylinders in volume. MAPP is stable, unlike acetylene, and gives off an odour - as does acetylene - which is handy when you have a leak.I've used all of these oxy-fuel mixtures and have two preferences; acetylene & MAPP. Acetylene allows the flexibility of using your system for welding/brazing, as well as cutting. MAPP is valuable when doing a lot of cutting, and cuts thicker plates almost as well as acetylene.Most of my work is at Vancouver Drydock Ltd., where we use acetylene. In an auto restoration shop that I have in Fort Langley(not a professional shop) I will be using acetylene, as well. The determination that you need to make for yourself is whether you will be cutting a significant amount of steel, whether you wish to have a cut/weld process, & whether your shop conditions allow for the careful use of unstable gases. I know, it sounds funny to those "in the know" but, I was working with a fitter on a barge repair(last month) who kept cranking the oxygen cylinder valve "fully open" before starting his cuts & setting his acetylene regulator at over 15 PSI, all this for cutting less than 1/2", usually 1/4"! This guy had been in the steel industry - as a fitter -for 22 years!Good luck!Mike
Reply:Hey canadianwelder1Excellent write up. That should be posted somewhere under a fact section.
Reply:Thanks Sandy!Though I prefaced many of my comments on my own experiences, I humbly admit that I pulled the statistical info out of my library. Due to my father being a retired metallurgical engineer, I have a library that could rival the AWS!Mike
Reply:Well I choose LPG. Im a hack at it now. As in I hack the shiat out of stuff when I try to use it. Only done it once though. I got an LP tip. The old guy (welding suply biz for most his life) said I might should consider changing to an LP injector instead of Acetylene. What ever that is. He didnt say anything about the mixing chamber.
Reply:Most of my work is at Vancouver Drydock Ltd., where we use acetylene. In an auto restoration shop that I have in Fort Langley(not a professional shop) I will be using acetylene, as well. The determination that you need to make for yourself is whether you will be cutting a significant amount of steel, whether you wish to have a cut/weld process, & whether your shop conditions allow for the careful use of unstable gases. I know, it sounds funny to those "in the know" but, I was working with a fitter on a barge repair(last month) who kept cranking the oxygen cylinder valve "fully open" before starting his cuts & setting his acetylene regulator at over 15 PSI, all this for cutting less than 1/2", usually 1/4"! This guy had been in the steel industry - as a fitter -for 22 years!Good luck!Mike[/QUOTE]*********************************************I always felt like a welder is a welder and a fitter is a fitter!and, when a fitter is working with a welder , he should just stick to his fitting and leave the combo work to the welder .[SIZE="5"Yardbird"
Reply:It is odd that the drydock is using acetylene. VSY was using MAAP last time I was there which was many years ago. The yard didn't want acetylene especially because of the flamability. Actylene will ignite from about 2.5 percent air fuel ratio all the way up to 85 percent. Propane is 2.1 to 9.5 percent. Many shipyard fitters are unticketed and just learned their skills from others. The history of ship fitting and welding is based on the old tasks of fitting shell plate and riveting it in place. When rivetting died the riveters were trained as welders. The arguments about who could use the torch and who was allowed to weld have been going on since. I had one yard welder helping me who boasted that he had a DPW3. It was a simple all position plate test that hadn't been used in the province for over twenty years. He was choked when I told him I had a 2 and a DPW 1. All those years and he had never upgraded.The reason for using acetylene in dry docks and confined spaces is that it is lighter than airwith a specific gravity of 0.9 ,air being 1 bar ,,propane has a specific gravity of 1.5 and is heavier ,so any leakage will settle at ground level or in ducts ,both gasses are highly flamable , the flamable limits in air are -for acetlene beween 2% to 82% for propane it is 2% to 10%. always remember that these bottles must be stored and used vertically. in the u.k lpg cannot be stored within 3 meters of any compressed gas cylinders .Marky2
Reply:A quick comment about opening the oxy cylinder all the way....when in welding school we were taught to open the oxy all the way because the valve is a double back-seating valve and opening it all the way prevents oxygen from leaking around the valve stem....acetylene on the other hand does not use this type of valve so we were taught to only open it around a half turn so it can be shut down in a hurry in case of a problem....i have worked in many welding shops in northern ohio and always disliked propane for cutting...just too slow on preheat and hard to keep a good cut going on thick cold steel...o/a setups are sold everywhere and easier to use.."in my opinion". the cost it might have saved didnt make up for its rather poor "manual" performance..as far as acetylene being dangerous and unstable..as long as it is used properly by a educated person it is pefectly safe..eg. always use your tank in the verticle position to prevent syphoning the acetone out of the tank wich is ONE of the things in the tank that keeps the gas stable.."have seen billy-bobs in scrap yards with their tanks laying on there sides...nice purple flame".....and i never use much more than 8 pounds of acetylene to cut..if i need more heat i put in a larger tip...wow,i talk too much.....later
Reply:ok i know ive brought back a post from the past but can propane cut just as thick material as acetylene?http://datingsidorsingel.com/
Reply:I cut with Propane, and Propylene, both can cut whatever needs to be done with no problem. Unless you do alot of oxy fuel welding leave the acetylene in the past with uncoated stick welding rods.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:i was taught that using acetylene on a large rose bud and powder coating will suck acetone from the tanks. i cant prove this.IPS Owner/[email protected]
Reply:Table : Fuel Gas CharacteristicsFuel GasMaximum Flame Temperature °COxygen to fuel gas Ratio (vol)Heat distribution kJ/m3 PrimarySecondaryAcetylene3,1601.2:118,89035,882Propane2,8104.3:110,43385,325MAPP2,9273.3:115,44556,431Propylene2,8723.7:116,00072,000Hydrogen2,8340.42:1--Natural Gas2,7701.8:11,49035,770
Reply:I use an Allstates torch specially designed for propane. Propane rocks for cutting. It doesnt carburize the cut and you can file it after cutting. You can hold the tip quite far away. I get a clean smooth cut through sheet metal by just rolling the tip sideways and cutting upto six inches away. Propane can be used over a very wide range of pressures unlike acetylene which is limited to 15psi. This means you need fewer tips to do a variety of jobs and also you dont have to worry about the draw on the tank. Propane works fine for brazing but its almost worthless for welding - the chemistry is wrong. (Although I have used it to do a "forge weld" in which the temp is way below the melting point of steel) I believe the rosebud on my torch will outperform any similarly sized acetylene rosebud. I have heard of a head to head competition propane vs actylene melting a 1" sq block of steel and propane won by a large margin.OTH propane is nasty. It has a wide ignition range , it's heavier than air and will pool like a liquid. A slow leak can build up in a crawl space or low cavity and flash suddenly with disastrous consequences. Acetylene leaks go skywards.Last edited by maddog; 09-06-2007 at 11:33 AM.355# Hay Budden3# Hofi HammerPropane ForgeIdealarc TIG 300/300AllStates Oxy Propane torchSmith Little Torch
Reply:I use propane on my torch setup. I was trained on Acetylene but preffer propane. I've noticed propane is less likely to pop like acetylene is. I've cut 1" no problem with my torch. I've never had the need to cut more in my home shop.
Reply:1" is kids stuff, I can cut foot thick scrap with propane and the right tip.Disclaimer; "I am just an a$$hole welder, don't take it personally ." |
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发表于 2021-8-31 22:56:56