Cutting....acetylene vs propylene

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For almost 40 years I have used acetylene mainly because that is what I was taught about in High School.   Am thinking of switching over to propylene.  Wondering about things like cost and safty.   I assume I will need new regulator and tip.   Some general questions:Will I need new hoses?   What is the cost difference?   Will a propylene container fit in my cutting torch cart?Does a bottle of propylene last as long as a bottle af acetylene?Are tips easier/harder to keep clean?Is cutting easier or harder?Safety....is one safer than the other?Any other info would be appreciated...thanks
Reply:We use propylene. We switched from acetylene to MAPP a long time ago, then the company switched gas suppliers, and the new supplier didn't carry MAPP, and switched us to propylene. It cuts about the same as the MAPP. As far as the safety goes, here is how it was explained to us. Acetylene is explosive in air in a very wide range of concentrations, others have a much narrower explosive range, therefore "safer". Liquid fuels don't rely on acetone for stabilizing..."safer". No limit on operating pressures vs acet. at 15 psi..."safer". You can get many different sizes of bottles. Ours fits the same cart.Propylene, or most any liquid fuel, will last a lot longer than a bottle of acetylene, but your oxygen consuption will probably increase. The acetylene bottle is full of acetone with relatively little fuel. Propylene is all fuel. An empty bottle is light as a feather.Cutting isn't easier or harder, but the flame to plate distance is more forgiving with proplylene. Might need more preheat time than you're used to.Tip cleanliness isn't much different. Tips are different. You'll need tips for propylene. Might need new hoses...there are grades of hoses for acet only, and some for all fuels. I don't know the designators off the top of my head.Don't know about costs, as I don't deal with the money. Your gas supplier should be able to educate you on cost comparisons.
Reply:I use chemtane, but I've been told it's similar to propylene.  You can use your acetylene regulator as long as you're not going to use fuel pressures above 13 psi, the most i've used for cutting is 7 psi on a #2 tip.  You will however need new tips, designed for propylene/mapp gas and grade T hose if you're currently using grade R hose (only for acetylene).  Propylene uses more oxygen than acetylene does, so a bottle of the same size will last you much longer, but you'll go through oxygen quicker.  Since oxygen is pretty cheap and your gas consumption will be lower, it should save you some money, although I can't comment on the price of propylene.  The bottles are about the same size as acetylene and propane bottles, so they should fit in your cart.  Tips are either 1 piece or 2 piece construction, I've found that they require less cleaning, depending on how you use the torch, but the 2 piece have more orifices, which can be fragile.  Cutting is easier I think, you don't need to have the tip so close to the steel, but I can't seem to get my set up to make as quite a nice of a cut as with acetylene.  Acetylene is very unstable, so propylene is safer and you don't have to worry about withdrawl limits, but it is very flammable like any fuel gas and should be used with caution.
Reply:Chemtane is about 35-40% cheaper to run than acetylene. There is also a 1 to 7 tank ratio on acetylene to chemtane so you get a lot more cutting per bottle change.To convert you do not need to change regulators, but you do need to change hoses to type "T". They do make propane specific torches, but changing tips ( must for safety reasons ) is all thats neccessary.I agree with Weld4d is isn't harder or easier to cut with than acetylene just a little different as you need to adjust your tip hieght.I still keep acetylene around for 3 reasons, 1:  I have the tank setup and I only need to fill the bottle once in a great while 2: its nice to have a second cutter around on occasion 3. ( big one ) you can't oxy weld with chemtane, I don't do it much of this any more but when I do its nice to have.If your starting out new go chemtane it costs a little bit more for hoses, less for the tanks ( 60 lb tank is about $200 ).Chemtane is a trademark name parts of the country it goes by different names, and the mix isn't exactly the same, no big deal you and I can't tell the difference, I cut with it not chemical analyis it in a lab.
Reply:I've always felt if you were going to switch away from aceytlene, why not go to propane and be rid of specialty fuel gases altogether?  Run out of gas on a Sat afternoon?  No problem, go switch your BBQ tank with another one at wherever.  Run out of gas on your grill?  No problem, got a spare in the shop that'll get you by.    There's a lot more competition on price as well.A middle-range fuel gas that I would still have to buy at a LWS just doesn't offer enough advantages to me over "regular old" propane to be worth the hassle.And yes, I switched to propane from acetlyene earlier this year.  Couldn't be happier with my choice.
Reply:I'm looking at getting a torch setup for my garage within the next few weeks or so and I'm trying to figure out the best for me. I was at my LWS and they were advertising new Propylene, but what are the advantages or disadvantages with Propane in terms of prices, preheat, cutting ability and how long it lasts in comparison to Acetylene and Propylene?
Reply:Hmmm, I dont know anything about propylene, but one of my friends switched to Propane, and he loves it. [ame]http://www.youtube.com/watch?v=Uo4w8A8oYkw[/ame][Account Abandoned 8/8/16 Please Do Not Attempt Contact Or Expect A Reply]. See you on YouTube! -ChuckE2009
Reply:I've used propane with a Harris torch to cut for over 30 years.  Use the proper tip for the material thickness and you are good to go.  I have tried Propylene a couple of times at trade shows and it works as good as propane.  The down side of propane or Propylene is it produces too much soot fo fusion weld.  I keep a bottle of Acetlyene around just for those cases or use the TIG.  I use the same regulator with both gases just have an adapter to switch abetween tanks.Remember, all the fuel does is pre-heat.  The oxygen does the cutting.Dan
Reply:Originally Posted by tbone550I've always felt if you were going to switch away from aceytlene, why not go to propane and be rid of specialty fuel gases altogether?  Run out of gas on a Sat afternoon?  No problem, go switch your BBQ tank with another one at wherever.  Run out of gas on your grill?  No problem, got a spare in the shop that'll get you by.    There's a lot more competition on price as well.A middle-range fuel gas that I would still have to buy at a LWS just doesn't offer enough advantages to me over "regular old" propane to be worth the hassle.And yes, I switched to propane from acetlyene earlier this year.  Couldn't be happier with my choice.
Reply:Originally Posted by tbone550I've always felt if you were going to switch away from aceytlene, why not go to propane and be rid of specialty fuel gases altogether?  Run out of gas on a Sat afternoon?  No problem, go switch your BBQ tank with another one at wherever.  Run out of gas on your grill?  No problem, got a spare in the shop that'll get you by.    There's a lot more competition on price as well.A middle-range fuel gas that I would still have to buy at a LWS just doesn't offer enough advantages to me over "regular old" propane to be worth the hassle.And yes, I switched to propane from acetlyene earlier this year.  Couldn't be happier with my choice.
Reply:Choosing the right gas, would depend on what you would be using it for, each has their own specific advantages or disadvantages over the other (price is usually a big one)....I am sure the average joe shop wouldn't notice a significant difference in manual cutting between the gases....pick the cheapest, cant go wrong and everything is safer than acetylene
Reply:Originally Posted by Liquid_PyroI am sure the average joe shop wouldn't notice a significant difference in manual cutting between the gases....pick the cheapest, cant go wrong and everything is safer than acetylene
Reply:Originally Posted by welds4dI can't disagree with you tbone. I'd like to try propane, just to compare it against propylene. It wouldn't bother me at all to ditch the propylene. Our storeroom fills propane bottles for forklifts and gas grills, so it would be pretty convenient.
Reply:propylene..chemtane whatever...they are propane with additives to increase the BTU's and flame temperature.They use the same bottles, regulators, and torches as propane.The expense is not that much more than propane.
Reply:propane (CH3-CH2-CH3) propylene(CH3-CH=CH2)essentially the same pure gas, but not exactlyXMT304 (school)SP125+ (home)HF 4x6 BandsawGood judgement comes from experience and much of that comes from bad judgement.