propane or acetylene ?

[junkfxr]

I have been doing mobile welding and repair on heavy equipment since the late 80's and all I have ever used is propane. The biggest reasons are cost, I own the tanks, I can get them filled on the weekend. when the gas grill runs out we just grab the tank off of the truck, and many more, mostly for convience. All of the scrappers around here use propane and liquid O2. The regulators and torch handles are the same, just different tips. The propane tips are two piece and much easier to clean. You should also use T grade hose (all fuel rated). Cut, heat, braze and solder with it, just not weld. Propane doesn't create a shielding gas. I've cut 4" plate with the right tips and uven use propane for a big rosebud for preheating.

 

[Baby Grand]

I hope you're not all really using liquid O2

 

[GE222]

I want to thank everyone for their contributions to the original topic. It was was probably the most informative of any posts so far in this forum.

I have always used acetylene for the past 27 years, any I can't remember anyone that I know of using propane instead. I will certainly consider this option.

 

[Renze]

I have ordered the propane setup at my local tool dealer this afternoon. He was 25 euro more expensive than what i could buy online, but transport would cost me as much. Next to that, i need to put some trade in return for the times i come to him at late saturday evenings when i need a spool of welding wire or a bottle of gas.
Cheapest is not allways best, a good relationship with a reliable adress will save you more than the last few euros at purchase.

I will post photos of the gas bottle cart i'm going to make: My father stopped keeping pigs 2 years ago, and there are plenty of old feed carts with solid caster wheels to use under my torch trolley.

 

[Wis Bang]

I hope you're not all really using liquid O2

I watched scrappers dismantiling a chemical plant. They had a 100# propane bottle and a Dewars bottle of Oxygen. They allow one to withdrawl either gas or liquid in the lab but I think they were using it for the capacity as the expansion of liquid to gas is around 800 to 1 giving them alot of O2 per bottle. These guys were burning 8 - 10 hours a day and I don't remember seeing them changing bottles alot.

I used to dispatch tankers of liquid O2 and one 48,000# load of liquid was enough to refill the tanks at 5 hospitals in New York's 5 boroughs. We had one specialized trailer that had an expansion unit under the belly and he would go to a naval base and recharge all the O2 storage on a nuke submarine. Only had one driver w/ the clearance to do this and it was a long time b/4 9/11

 

[RPW]

If you want to weld but not use acetayline then you could use MAPP. Slightly less temperature than acetalyline and only has a narrow explosive range compared to acetayine. And just to reiterate don't use acetalyine tips for propane and visa-versa. Won't work or will work very poorly.

 

[toy]

I have decided to bite the bullet and buy a torch set:

I could get a plasma from 350 euro onwards, but the dealer i regularly buy stuff from, offered me a small professional quality one for 1750 euro, he said he wont sell the cheap ones because he has to attach his good name to anything he sells.
With O/A or O/propane i can also heat, and weld if required.

Propane is cheaper, but cuts rougher ? Is the price difference that big between propane and acetylene consumables ? Can you cut both with one torch ?

Could you change that 350 euro into USA dollars? I have seen euro used in quite a few posts but am clueless to the exchange value of a euro.

 

[MJPetersen]

At today's rates that 350 Euro represents about 520 USD.

Mike

 

[Renze]

Ok i have been cutting yesterday, and have a headache today: Next time i'll continue scrapping galvanised pig cages, i'll use the gas mask my brother kept from his military time.

Within 3 hours i used 2/3 of the 100 liter oxygen bottle, and the bottle froze on the outside even though it was 10 degrees C outside. Is this normal, or am i using way too much oxygen ?

How about this neutral, carburetting, oxidizing flame ? 10 years ago, at school, i learned how to adjust an O/A welding flame, but do i adjust the cutting flame with, or without cutting oxygen ?
I used 3 bar of pressure on the oxy as well as propane. The torch knobs adjust the gas flow for the heating flame , but the cutting oxygen is controlled only by the pressure regulator. How much should i use ?
I think i have Messer Griesheim tips on this torch.

 

[MJPetersen]

Renze,

Careful cutting galvanized the fumes are toxic! Only in well ventilated and don't breathe it.

I would say too much Oxy. 2 bar should be plenty for the ox. I use about 1.4 bar with acetyl. I sincerely doubt that propane should be that high either. How good are you are converting from pounds to atmos? try this chart of pressures.

I know that it is for Victor torches, but it will give you an idea. Maybe you can find something equivalent in metric pressures. if you do post it for my benefit--I am coming the other way. look on page 7-19 at the victor 1-101 torches ----Oh later on in the French section they list the pressures in metric pages 7-22. maybe there are other languages too.

how is your French? Also Spanish is a choice.

Mike

 

[Renze]

Careful cutting galvanized the fumes are toxic! Only in well ventilated and don't breathe it.

Problem is that all fuses blow as soon as i turn on the light in this pig barn that has been abandoned since 2 years: let alone turn on the fans !

I do drink lots of milk when working in there. Its known for decades that milk takes away the poisons of zinc and paint primer fumes. Still think i gotta find that gas mask though...

I do need 3 bar to cut this dirty scrap.. The oxygen consumption in relatively thin steel disappoints me a bit, but its still better than using an angle grinder...

 

[MJPetersen]

Renze,

I found what I used to make myself a laminated card for next to my torch. I will attach it as a PDF. It states that it is for Acetylene/Fuel Gas, so it should be appropriate for Propane also. It has both psi and metric. If you adjust the flame to a slight oxydizing state (without cutting oxy), then it will cut without having 3 bar. Maybe you need more heat to burn through the junk--your cut will not be as pretty (but then cutting galv is not going to be pretty). Turn up the heat (more gas volume and lower the pressure), but turn down the oxy pressure. According to the chart you will not need 3 bar until you are cutting material thicker than 25 mm and for most material .345 to .5 bar on the fuel should be sufficient. I gleaned this material from Victor's site a while ago--I did not just now make it up.

Good luck!!

Mike

 

[Transit]

Reading through all the replies, not one word of safety. Not that it is a deal killer, but be aware there are safety issues with any compressed gas that should be taken into account. Some localities will not allow flammable compressed gas to be stored at home; read, cannot use it. There are posts on TBN about compressed gas safety, read before you buy.

 

[smfcpacfp]

Reading through all the replies, not one word of safety. Not that it is a deal killer, but be aware there are safety issues with any compressed gas that should be taken into account. Some localities will not allow flammable compressed gas to be stored at home; read, cannot use it. There are posts on TBN about compressed gas safety, read before you buy.

Probably a good reason why nobody mentioned safety - the original poster didn't ask about safety.

 

[Prodirt6000]

acetylene all the way!

burns much hotter. so many more uses

 

[Renze]

Probably a good reason why nobody mentioned safety - the original poster didn't ask about safety.

I already knew that propane is much safer, because it is more stabile: Propane turns to liquid when compressed to 200 bar, where acetylene explodes above a certain pressure. Thats why the acetylene bottles are filled with a sort of aceton mud. When decompressed, the aceton releases acetylene. As i mentioned in another thread, when you bounce a bottle of acetylene, you can cause a chemical reaction inside the bottle which will generate heat, and unless the bottle is thrown into cold water, will explode the bottle.
Also with acetylene you need a flame extinguisher valve, to prevent the flame to bite back into the bottle. Propane doesnt backfire because it doesnt burn unless it is mixed with oxygen.

I am allowed to store the BBQ propane bottle at home, and the same bottle is used for the torch. No regulations here.


By the way, i just burnt my first 100 liter bottle of oxygen yesterday. I butchered old farm machinery, a silage feeder bucket, of which i salvaged the hydraulic cylinders for my grader project, and the slatted floor elevator for my bale processor. Oh, and we scrapped a hydraulic tail lift off an old truck we scrapped, which will become my brothers tractor drawn midi excavator (7.5t) hauler, tilt bed, aluminium foldable sides, with a Hiab crane up front.

Scrap prices are rising slowly, even though the past two months the prices have dropped 2 cents again. In the news was that in Holland, the recession is officially over because the economy is growing again, so i think the scrap prices will be back to 15 cents when in January, new production orders for the new fiscal year, are handed out to manufacturing and construction companies. I have lots of it, so i hope to take the scrap out at last years peaks (35 cts per kg !)

 

[MEhorseFarm]

In a past life I sold welding equipment and gases. The Acetylene vs Propane debate for cutting was always being knocked around amongst my customers. A lot of it came down to personal preference and cost. But be aware, there is a hidden cost that is often overlooked, and has not been mentioned in the forum. That is the amount of oxygen needed to achieve oxidization. Acetylene requires a 1.5:1 ratio (1.5 cubic meters oxygen to 1 cubic meter Acetylene) whereas Propane requires 4.5:1 ratio. The cost of the tank of propane is cheaper, but depending on what you are paying for Oxygen, that savings may not be as great as you think. Both will work for cutting just fine and propane will actually cut thicker steel (up to about 8") than Acetylene (up to 2") but for most of us, cutting less than 2 is more than adequate.

 

[MJPetersen]

Ah. That explains Renze's statement that he used significantly more oxy than I thought normal--thnaks for that bit of info.

Mike

 

[Renze]

But be aware, there is a hidden cost that is often overlooked, and has not been mentioned in the forum. That is the amount of oxygen needed to achieve oxidization. Acetylene requires a 1.5:1 ratio (1.5 cubic meters oxygen to 1 cubic meter Acetylene) whereas Propane requires 4.5:1 ratio. The cost of the tank of propane is cheaper, but depending on what you are paying for Oxygen, that savings may not be as great as you think.

Yes the oxygen consumption is a bit of a disappointment. I pay 40 euro for a refill of 200 bar in a 50 liter bottle. Propane is 28 to 30 euro, dont know the exact size.
The acetylene bottle i'd have to hire for 20 euro per month and 70 euro per fill or so. the Oxygen bottle rent is 70 euro per year.
I'm not that much cheaper as i thought but it works for me, and i dont pay rent for an acetylene bottle when not in use.

 

[helenxu96]

As I know, Oxy-gasoline cutting torch system is an ideal alternative to tradtional compressed gas cutting system. becaue it can save more than 80% fuel cost and absolutely no backflsh risk. Very safe. Maybe you can ger more information about it by visiting this website www.gyjd2008.com