Propane v.s. Acetylene......

i just recieved a private message from a fellow "HAMBER".

he is asking me the difference and benifits of gas welding with propane or acetylene.

he has been told by others not to waste his time GAS WELDING anything because it is outdated and other processes such as M.I.G. (metalic inert gas welding) is better and faster.

well i look at it this way............

someone wants to learn something else besides what everyone else is doing and he wants to expand his skill base and be more versital.

to start off with;

PROPANE is a byproduct of oil refining and it is also seperated out of natural gas. propane contains a lot of moisture and is a cold burning hydrocarbon fuel.

on the other hand ACETYLENE is a hydrocarbon fuel but it is a hotter burning fuel. acetylene was originally derived from a couple of different origines but today it is created from calcium carbide. after the extraction it is suspended in acetone to keep moisture out of it and it is suspended in a pouris element consisting of balsa wood and asbestos, in a steel preasure cylender.

the equipment for using acetylene is similar but different. the parts in the regulators have to be set up for acetylene, the hoses coming from the regulators are different because of the chemical composition of the different gasses. the torch tips are completely different because of the differences in the fuels and the burning temperatures they burn at when mixed with oxygen.

acetylene has more versitility to it as far as welding, heating, anealing, cutting and many other options.
propane dose not have the amount of carbon in it if a piece of material needs to be carbonized for anealing. as far as heating goes a propane falme produces a falme that is about 4500 degrees F, where as acetylene produces a flame that is about 6000 degrees F and higher.

i hope this informatin is helpful.

 

Sounds like everything you need to know, except what he asked:
"he is asking me the difference and benifits of gas welding with propane or acetylene."

 

I thought that propylene was the welding gas of the future, not propane. What is your opinion of propylene?

 

you are talking about "MAP GAS" that has a lower flame temperature from propane.

 

I have heard that if you do a lot of cutting then its good to have a propane setup as its useful for cutting. Propane is cheaper and you can get it at many stores.

http://www.cousesteel.com/AndysPlace/PropaneAcetylene.html

 

I have heard that if you do a lot of cutting then its good to have a propane setup as its useful for cutting. Propane is cheaper and you can get it at many stores.

http://www.cousesteel.com/AndysPlace/PropaneAcetylene.html

 

We used propane in the cutting torch when I worked at the junkyard many years ago, mainly because it was cheap. I run acetylene in my torch at home, and I still gas weld some things. for example, I'm better at welding exhaust pipe with a torch than with the wire feed. And cracks in sheetmetal.

 

well i guess i really opened a can of worms on this one.

when is the shit hitting the fan on this one...........

 

I have the same question can i weld with propane and i mean weld steel not braze.

 

Tim I think your right, we use to salvage stuff back in the 70's. Cut up combines ,farm equip ect.. Propane was a bunch cheaper. It took longer to get something hot initially but was sure a lot cheaper. Oh, and back when aircraft were in their infancy, many men went to war and most if not all aircraft stuff into WW2 were oxy-Acetelene welded. Nothing wrong with a oxy-acet weld at all if done right. There was a lot of aircraft aluminum torch welded also in the factories. Lippy

 

Cutting with propane works fine use it all the time (with a propane tip). You can get by brazing with propane but not welding to much free oxygen it will burn up the metal.

 

Propylene/Propane is great for cutting steel. It leaves very little if any slag. Compared to Acetylene, it does not weld worth a crap. Can't get a good flame to hold at the proper settings. When you do it seems to burn through easily. Switching to back to propane it seems so much easier, like night and day difference.

MIG welding body sheet metal I have learned doesn't seem to work as well as "gas welding". MIG wire is a higher tensile strength steel and doesn't seem to be as easily reformed after welding. It seems to crack where the high strength steel meets the old body.

 

One more thing. You only have to change the hoses, not the regulators.

 

Yep, most scrappers around here use Propane because it is a lot cheaper touse for a lot of cutting. It works ok if you aren't concerned with clean cuts as the cuts aren't usually that great in appearance.

I don't know anyone personally who propane to weld but I'd suspect that it might not give the best welds.

A lot of us still drag out the the torch and tanks to weld sheet metal on a regular basis simply because that is what we are most comfortable with even if we have a mig or tig available. That should be the criteria, weld with what you are most comfortable with and what you have and don't worry what the drive in parking lot experts are saying.

I think a lot of guys are bent on "getting it done fast" and gas welding is usually a bit slower and take maybe just a bit more finesse than mig welding.

 

Thank yall for the answers the knowledge base here is amazing. I have been wondering this for awhile and havent been able to find any definative answers now I know, again thanks yall.
Later
Mike

 

When I took a state welding course,there were 2 instructors..the younger guy could stick weld upside down,with his eyes closed,at least it seemed that way. The older instructor,who was close to retirement age,taught us about gas welding,admitting we wouldn't ever use it. I told him that I would,cause I wanted to play with rusty old cars,and he appreciated my attitude.
The year was 1973...
I'm grateful the old guy took the time to show me. Nobody else seemed to give a shit about gas welding. I guess after he retired,so did the gas welding part of the class. That guy could do magical things with a torch,I'm glad he was still there when I took the class.

 

In California propane is half the price of acetylene. As mentioned above you can use the same regulators with different settings. I was told you could use the same hoses but they will not last as long for propane. You can use the same torch but as stated before the tip is different. Good luck.

J

 

I use propane in my business every day with no issues, but when cutting with propane you consume a lot more O2 than with acetylene. We really don't do any gas welding anymore so I can't answer original question.
41plym

 

Some time last year i heard a main acetylene supplyer/calcium carbide mining operation had a catastophic explosion or fire that affected the supply of acetlene for the U.S. driving prices up. My welding instructor said that a lot of places were converting over to propane because of the cost.

 

I think that an oxygen/acetylene torch set is one of the most versatile tools in the shop and should be one of the first major purchases a person should make for his shop.
A propane torch may be better for processing a lot of scrap metal, but for the average hot rodder shouldn't even be a consideration.
The basic skillset that I learned from O/A welding converted easily to MIG and TIG.
It is difficult for me to imagine not having an O/A setup!

~Alden

 

Actually, MAPP gas is a mixture of methylacetylene (also called propyne) and propadiene. Propylene is different, and it has a more energetic molecular composition than propane. I have heard its cheaper and safer than acetylene, but I don't know if it's worth a damn to use in the shop.

 

you are exactly correct. aluminum and steel are still welded today. the trick with welding aluminum is watching the surface of the piece being welded. i personally have tried gas welding aluminum and failed but on that note i have seen folks do it and when it is done it is flawless. learning that is extremely time consuming, and the technique is the secret.
gas welding steel is the same but the melting temperature is about douple that of aluminum. heat disapation is double if not more in aluminum compared to steel.

 

when i was teaching welding for Los Angles Unified School Distric, i always started a new student on gas welding for the simple reason it got them to start with concentration, and developing consistency skills. from there i would move them to arc welding and have them learn how to run E-6010 stick rod. that is where puddling gets carried forward from gas welding. and things move forward from there.

 

Steel is easy because you can see how hot it is, by the color. Aluminum mostly looks the same until it goes "poof". Since aluimnum conducts heat so well, it mostly all melts at the same time, while steel only melts right where you're applying heat

 

I was taught to use oxy/hydrogen for gas welding thin aluminum, it burns a little cooler, and gives a little more margin between puddle and "poof".

 

Learning to gas weld will teach you how to weld.....period. Opinion of course but I have done a huge amount of ox/acet welding.

 

The local community college here starts off with gas welding and it's good for teaching fundamentals. Plus, learning how to control the torch is very helpful for when you move to TiG welding. As for welding aluminum, the most common mistake people make is failing to clean off the oxide coating, which burns at a lot higher temperature than the underlying aluminum. So they keep cranking the heat and once they do burn through the coating, they blow through the rest before they even know what happened.

 

Let me ask this..Can heat up a steering arm hot enough to bend it using propane instead of acetylene?

 

Yes.

 

Acetylene and oxygen give the hottest flame, hotter than Propane and oxygen.

Acetylene and oxygen can be used for gas welding, Propane and oxygen can not.

The reason for this is that one of the by products of the burning of Acetylene and oxygen is CO2 which is what provides the shielding for the molten weld.

Propane will not provide this shielding and as well as a lower flame temp adds a lot of moisture to the equation.