In article ,
"Dixon Ranch" wrote:

Its no wonder acetylene is getting expensive. How much of a performance
hit is using oxy-propane instead ?

Steve

My question also. Does propane require a different tip or torch? Can the
same hoses
be used for propane?

Bob


Yes, same hoses and regulators with propane. Cutting torch will require a
new tip. The tip is an entirely different design.

Propane seems to take longer heating and the cutting kerf will be wider as
best as I can remember.

It will also use more oxygen.



Yep, AT LEAST twice as much.

Dont believe me, though... Do the math:
Acetylene, C2H2, needs 2 oxygen atoms (2 bonding sites per atom) per
carbon (four bonding sites per atom) for 4, plus 1 for every two
hydrogen atoms (1 bonding site each) is 1, which makes 5 atoms of oxygen
per molecule of Acetylene to burn neutral - Since oxygen comes
"naturally packaged" in bundles of 2 atoms, that means we're going to
need to mix two molecules of C2H2 with 5 molecules, or 10 atoms, of
oxygen to achieve a "true neutral" flame - one that puts out nothing but
heat, water, and carbon dioxide. A molecule of propane, C3H8, needs the
same 2 per carbon for 6, and 1 for every 2 hydrogen for 4 makes 10 atoms
or 5 molecules of oxygen to achieve the same result. All told, you'll go
through oxy twice as fast with propane as with acetylene. Start cutting,
or running an oxidizing flame, and you'll run through it even faster.

Of course, looking at it from the flip side, you're going to burn half
as much propane as you would have acetylene for the same tank of oxy,
but if I'm not mistaken, oxy-propane doesn't burn as hot as
oxy-acetylene, so you have to use more of it to get the same heat (not
sure on the BTU numbers - I'll have to look 'em up. I *KNOW* they
differ, just not by how much) which makes me think you're likely going
to be doing good if you pretty much break even when you get to the
bottom line of the refilling bill.
Another factor: How much does propane cost in *YOUR* area? Out here in
Kali-fornicates-ya, the last refill of my little grille-tank - standard
5 gallon jobbie - set me back a fairly stiff-seeming 14-ish bucks.

D'OH! Proofreading the math just made me realize why/how I mangled the
acetylene triple bond into a double bond in my other post!

Brain fart of epic proportions!

PROPER drawing of acetylene:
_
/ \
H-C---C-H = C2H2 = Acetylene
\_/

^^^ = triple bond

NOT

H H
\ /
C=C = C2H4 = Ethylene, not Acetylene!
/ ^ \
H | H
'- = double bond

as in polyethylene twine tying your hay bales, or ethylene glycol for
the car radiator. Good grief... How did I overlook a screwup *THAT* big
and basic!?!? And *YOU* missed it too, Teach!!! Guess that helps me
not feel *QUITE* so bad...

--
Don Bruder - - If your "From:" address isn't on my whitelist,
or the subject of the message doesn't contain the exact text "PopperAndShadow"
somewhere, any message sent to this address will go in the garbage without my
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