Acetylene Vs Propane

[drsportster]

Propane may be cheaper by a lot But I was taught with acetylene and will pay more gladly for the better heating gas How do you feel about non-acet gases for use ?

 

[joeysmith]

I use both
Propane works better cutting rusty nasty stuff

 

[DanielW]

For cutting and heating, oxy-propane works just as well as oxy-acetylene. Perhaps even slightly better (as long as you have grade T hose & regs and the correct tips). I'd never go back to acetylene for cutting and heating. But I still keep an O/A kit at one farm for brazing (or welding, not that I do much gas welding anymore). Best part about propane is being able to use a big rosebud or other large heating tip. You're very, very limited in how large a rosebud you can use with acetylene - you need a massive tank to handle even a medium-sized rosebud. With acetylene, you have make sure your hourly flow rate of acetylene is less than 1/7 of the tank's total volume, or else you can draw up acetone and cause some major danger. With propane, you can run as big a rosebud as you could want off a 20# BBQ tank.

You do have to consider that propane requires a lot more oxygen. So you're saving on acetylene cost, but losing on oxygen cost. You're still usually much further ahead with propane, because O2 is cheap and more commonly available. But if you use propane a lot, you want to keep a spare bottle of O2 around (or be able to acquire one nearby).

 

[will-max dairy]

For cutting and heating, oxy-propane works just as well as oxy-acetylene. Perhaps even slightly better (as long as you have grade T hose & regs and the correct tips). I'd never go back to acetylene for cutting and heating. But I still keep an O/A kit at one farm for brazing (or welding, not that I do much gas welding anymore). Best part about propane is being able to use a big rosebud or other large heating tip. You're very, very limited in how large a rosebud you can use with acetylene - you need a massive tank to handle even a medium-sized rosebud. With acetylene, you have make sure your hourly flow rate of acetylene is less than 1/7 of the tank's total volume, or else you can draw up acetone and cause some major danger. With propane, you can run as big a rosebud as you could want off a 20# BBQ tank.

You do have to consider that propane requires a lot more oxygen. So you're saving on acetylene cost, but losing on oxygen cost. You're still usually much further ahead with propane, because O2 is cheap and more commonly available. But if you use propane a lot, you want to keep a spare bottle of O2 around (or be able to acquire one nearby).

x2...

I'll only add that I still keep some acetylene around, even for cutting, because propane makes a flame where the heat is further from the torch tip (at least that's what I read... I'm sure that more experienced welders/machinists may have an input on this)... so you're supposed to hold your torch tip further from the work with propane.

Anyway... if I need to cut something like a bolt hole that's too large to drill... and I want it close enough to perfect that I don't waste time grinding or filing... I use acetylene for the accuracy provided by being able to hold the tip closer to the work.

I also believe that acetylene is the only way to produce a perfectly neutral flame with only CO2 as a bi-product, to act as a shielding gas for welding with a torch... propane would introduce impurities.

For that reason, I kept a couple of small welding tips around... thinking that oxy-acetylene welding was my best option for thin sheet metal... and then a friend gave me an old MIG that he had laying around... so I don't bother with that usage of acetylene anymore.

Between having the MIG around... and having a propane tip for most cutting and heating...

I hardly use much acetylene anymore.

As a matter of fact, I was going to change over the cutting tip to acetylene just to use up my bottle and get a fresh one. I don't like having a bottle around for more than a year or two.

 

[will-max dairy]

I guess I had another comment.

Before I got a propane cutting/heating tip... seemed like my farm equipment was always breaking on a Saturday or Sunday...or that's when I had the time to do a bunch of work anyway. I was always sweating about burning through my acetylene over the weekend and getting stranded, because there is noplace to exchange a bottle around here on the weekend.

With propane, I can run to the convenience store, get another tank of propane, a coffee and a bag of chips... all weekend long.

 

[BarnyardEngineering]

If I'm going to waste gas restarting cuts over and over and over, I'd rather waste the cheaper gas.

No matter what gas I use, what pressures I use, what tips I use, how I adjust the flame, how fast or slow I move, I can't cut more than a fraction of an inch before I lose the cut. Tried going by the book. Tried more gas, more oxygen, less gas, less oxygen, freehand, using guides, different torches, different regulators... doesn't matter. Everything has to be JUUUUUUUUUST RIGHT. Any little twitch and I'm out of the cut. I'm naturally uncoordinated, twitchy and spastic, so I go through a lot of gas...

 

[moresmoke]

I keep my little acetylene bottle for when I need it. Cutting bearing races, brazing, welding etc. I could braze with propane, but haven’t found any tips for my set yet.

I have a handy little 5lb propane bottle I use with the torch set. I can fill it off the tank outside the shop and there is usually at least 50 gallons in there.

 

[Bob Bancroft]

Propane may be cheaper by a lot But I was taught with acetylene and will pay more gladly for the better heating gas How do you feel about non-acet gases for use ?

We didn't have a torch at home. When I went to work in a shop in the early 70's I learned on an oxy/acetylene torch. When I bought my own set the dealer talked me into MAPP gas in place of acetylene. I hated it. Even with the special tips they sold me it was so cold it took so much longer to get anything to start cutting. And it lasted forever! So when it was finally gone I switched to acetylene.

 

[Tony in SD]

I was taught in high school on A/OX. About that time frame, "Mr Haney" showed up at the farm and sold dad a LP/OX setup. Been using it ever since on the farm. At my age I probably will not go back to A/OX. LP/OX does what I need it to do. Cut, braze, rosebud.

 

[shaun wallace]

When I was into scrapping heavier than am now I used LP. Took longer to get hot and didnt cut as smooth. I have went back to acetylene since doing some fabbing some items,

 

[caterpillar guy]

for keeping the cut has a lot to do with the angle you hold the tip. Another words I try to keep the tip aimed a bit forward in the cut so it can sort of heat ahead of the flame cut as I go. When cutting a round or square hole I try to keep it straight through and move slower. I don't see much difference in the smoothness of the cut with either. Still have slag to chip off with a hammer and a chisel some and them grind the finer stuff off.

 

[Watthour]

Odd that no one has yet brought up plasma as a cutting option.

 

[rrlund]

We've always used propane because Dad didn't want to pay for an acetylene tank. I use the correct propane tip, but cutting is still way slower with the propane. A lot of stopping to wait for it to heat up again.

 

[joeysmith]

Odd that no one has yet brought up plasma as a cutting option.

Used that a lot on newer cleaner steel when I was doing a lot of fabrication in a prior job but it was horribly nasty on dirty rusty stuff
Especially oilfield pipe so normally used the torch on it

 

[kencombs]

Years ago I watched a guy that was really good with a torch turn off the acetylene completely after the cut was underway. Just straight O2, really nice cut. Just got to get it hot enough to burn and feed it oxygen. And other little details, like rock solid hand, perfect distance from the cut, pressure correct and travel speed. He had all that, I don't.

He could do that with propane too, just had to preheat more.

 

[will-max dairy]

Used that a lot on newer cleaner steel when I was doing a lot of fabrication in a prior job but it was horribly nasty on dirty rusty stuff
Especially oilfield pipe so normally used the torch on it

I wondered about that. So plasma has the same issues as arc welding when it comes to rust?

 

[m16ty]

Years ago I watched a guy that was really good with a torch turn off the acetylene completely after the cut was underway. Just straight O2, really nice cut. Just got to get it hot enough to burn and feed it oxygen. And other little details, like rock solid hand, perfect distance from the cut, pressure correct and travel speed. He had all that, I don't.

He could do that with propane too, just had to preheat more.

Yes, once the cut is started you can cut with just O2. O2 does all the cutting, the fuel is just their to preheat the steel to get the O2 started.

I’ve done the trick you describe, but you have to have a real steady hand to continue the cut very far.

 

[BarnyardEngineering]

Yes, once the cut is started you can cut with just O2. O2 does all the cutting, the fuel is just their to preheat the steel to get the O2 started.

I’ve done the trick you describe, but you have to have a real steady hand to continue the cut very far.

If you want to see someone who knows his way around a torch, check out IC Weld. The man waves the torch flame at the chunk of metal and then immediately starts cutting! Hardly any preheat? All I do is preheat. It's frustrating to watch.

 

[Hobo,NC]

If you want to see someone who knows his way around a torch, check out IC Weld. The man waves the torch flame at the chunk of metal and then immediately starts cutting! Hardly any preheat? All I do is preheat. It's frustrating to watch.

Does anyone have a link to the marker he is using.

 

[miangus]

As DR, I learned with acetylene tried propane tried map currently use acetylene. I even had the correct propane and Map tips. A trick when cutting rust is to grind a path where cutting or grind a short place to start.