[TheForge] Re: Burning Metal

Thu Nov 6 04:39:06 2003

Hi Chuck:

I'm not sure how my muddled ramblings lead to your question except perhaps I
didn't say the iron/steel is burning under the oxy jet. Once the steel is
hot enough to initiate burning under the oxy it is self supporting. Properly
set and guided by a steady hand you can certainly shut down the acet after
cutting starts and continue just with the oxy.

Oxides and slag inclusions that shield the iron/steel from the oxy jet stop
the combustion. Iron and steel within the cutable range of alloys produces
an oxide with a much lower melting temp than the unoxidized metal and is
literally blown out of the cut by the "pressure" of it's own combustion.

Ayup, improper regulator settings and tip selection is the #1 reason for
poor torch cutting. (Oh okay, dirty tips are right up there too.) I use an
Allstates oxy/prop rig at home and the regulators are self metering but at
work I'm always resetting the regulators. Everybody seems to want to run
5lbs acet and 40lbs oxy.  What really kills me is somebody will compliment
me on a torch cut, then rag on me for not having the regs set "right".
<sigh>

Frosty
------------------------
If it ain't forged
it ain't real.
Wrought iron is.
The FrostWorks

Meadow Lakes, AK.

----- Original Message -----
From: "Chuck Robinson" <[email protected]>
To: <[email protected]>
Sent: Monday, November 03, 2003 7:37 PM
Subject: Re: [TheForge] Re: Burning Metal

> Jerry,
> If this is true, how can I shut the Acetylene valve off when the cut
starts
> and complete a cut in metal 1/2" thick  with out the fuel supply?
> When I first started cutting  my 5+" thick steel anvil billets, I had
major
> problems with slag build up and sloppy wide kerfs or incomplete cuts.
> After reviewing my O/A cutting text books. I lowered the O2 pressure and
the
> cutting action improved dramatically. The higher the O2 pressure the more
> slag formed in the kerf
> The cutting action is exothermic.
> I believe poor O/A torch performance is mostly due to not adhering to
proper
> gas pressure for the tip size recommended for the steel thickness.
> Chuck