propane VS. oxy/Acetalene

[KToy]

ok so i have an oxy/acetalene cutting torch.

but i hear that propane is cheaper and cuts cleaner and stuff.

so should i spend money on some bigger tanks since we need them.

or should i get a propane cutting torch.


so whats better and why?

 

[dunatic67]

My father in law uses propane. I've only used his torch once 5 or 6 years ago. My impression was that the heat was lower- hard to get started but worked well after that. That was a very long time ago- one time use.

 

[KToy]

that was my thinking on it that is burns colder but so far iv got claims that it cuts cleaner. plus propane is a bit cheaper ya know.

 

[EZRhino]

It's not propane, it's propylene. And it's better for everything. I watched a demo at AirGas and was so impressed I bought the kit. You need to switch over to a different torch and tip set up, plus get the gas and turn in your acetylene tank. You can cut 1" thick steel like a plasma cutter, plus my favorite is the gouge tip (for removing welds) very cool.

EZ

 

[KToy]

so how much does it cost to convert to propelyne.

 

[EZRhino]

I think the torch kit with hoses and regulator was about $260, plus the tank....dont remember what that was. The thing with propylene is, you hardly use any of it. When you are cutting you set the regulator on like 1 psi. It will last forever at the rate I use it.

EZ

 

[KToy]

ok i have oxy/acetalene regulators right now.

can i use those and just buy the tank or do i need another set of regulaters.

also what about the handle/tip do i need a new one of those.


maybe i should just go to airgas huh.

 

[EZRhino]

Yeah , go talk to Jake. Also, when I was there I was getting my info straight from the Harris rep. They made it sound like my old regulators wouldn't work (the acetylene one, anyways.)

You'll also need to get smaller sized tips, because the ones that come with it are for cutting really thick steel.

EZ

 

[Herzog]

Good info... I'm going to look into this as well.

 

[anvil]

propane is C3H8

propylene is C3H6

Propane (like what you burn in your barbecue) works just fine in an oxy/acetylene torch. Propane is cheaper, but it requires more to make the same cut. It also takes longer to make the same cut. This is why many shops don't use it. Labor is expensive.

Propane tanks are higher pressure than acetylene tanks. You'll need a different regulator and an adapter.

propylene is also callled mapp gas. It is commonly used in cutting torches and burns hotter than propane, but colder than acetylene.

 

[EZRhino]

Yes, Propylene. Call Airgas if you don't believe me.

Propylene cuts steel better, faster and cleaner than acetylene. It is also safer to store and the tanks are a lot lighter. Next time Airgas has a demo day, you need to come down and check out all the kewl toys.

EZ

 

[KToy]

ill have to check it out.

 

[EZRhino]

Since Harkinoff doesn't believe me...

 

[Greg]

All our welders use propane for their torches on the railroad. And the torches get used a LOT. In all types of weather, usually cutting rail which as I'm sure you know is thick. Seems to cut fine, no striking problems, cutting problems, etc.

 

[anvil]

Calm down EZRhino. No need to call Airgas. Besides, salesmen will tell you whatever you want to hear. This is from the Miller website:

http://www.millerwelds.com/education/articles/articles60.html

Acetylene: Produces the highest flame temperature of all common fuel gases. The hotter the flame – the faster piercing occurs. The higher calorific value of the inner flame vs. that of other gases makes acetylene the fastest cutting gas with the least amount of distortion and the narrowest heat affected zone – which is why it is arguably the most popular gas. Also features the lowest oxygen-to-gas ratio of (1.2:1).

Propane: Lower flame temperature than Acetylene but has a greater total heat of combustion, making it equally fast at cutting. But with most of the heat being generated in the secondary flame, the flame is less focused, causing slower piercing times. Suffers from a relatively high oxygen-to-fuel gas ratio (4.3:1) required to meet maximum flame temperature.

Methylacetylene-propadiene (MAPP): Slower piercing and cutting times than Acetylene due to lower flame temperature, larger distributed heat source and gas flows – but can be used at higher pressures than Acetylene (i.e., less combustible). Oxygen-to-gas fuel ratio is (2:5:1).

Propylene: Similar in temperature to MAPP, hotter than propane, cooler than acetylene but requires a high oxygen-to-fuel gas ratio (3.7:1).

Natural Gas: Slowest gas for piercing, with lowest flame temperature and lowest total heat value.

Maybe someone else can find actual temperatures.

 

[EZRhino]

Calm down EZRhino. No need to call Airgas. Besides, salesmen will tell you whatever you want to hear. This is from the Miller website:
.

So now you're calling Jake a liar?

Interesting info. I had never heard of using oxy-propane before.....propylene was new to me when I saw it. There must be a different function of the set up with the different tips and such, because it feels MUCH hotter using my oxy-propylene set up rather than the old oxy-acetylene. In fact, the cut starts about twice as fast as it did before.

 

[anvil]

Who's Jake? I've never tried propylene. If it really starts a cut twice as fast that would be nice.

 

[harkinoff]

Since Harkinoff doesn't believe me...

Not that I don't believe you... I use propane for torching very much and notice no difference between it and acetylene.. I just didn't feel like an argue dude.. Sorry