[TheForge] Oxy/Propane reprise

[Ben Barrett]

Hmm.  My setup is almost identical to yours, and I have had good luck,
although there are some differences:
* I run my torch in a wind-free environment.  My own movements are
visible in the pilot flame of my fuel-saver, but not on the torch at
all.
* I have a smaller tip, #0/"aught" IIRC, but still a victor
oxy/propane tip on a clone torch body.
* I tend to keep my propane regulator around 3-5 PSI, and the oxy
around 20-30... sorry for the range here, but I honestly don't know
how accurate that is anyway (is an acetylene regulator but was new).
When the tip was new, I got about a 30" long flame, much longer than
anything I had seen on oxy/acetylene, very narrow and tubular and
well-formed, and I was told that I should be able to cut pretty far
away from the tip if I had good enough control to manage it.  The tip
has had some use now and not much cleaning but still maintains ~20" of
clean narrow cylinder of flame... now just recently I had taken to
running it slightly oxygen-rich, because of the increased intensity of
heat, which does seem to shorten the flame from its maximal length.
I might've been running the propane closer to 6 or 7psi in the
beginning, too, but have mostly been using this setup for heating (not
cutting) but the oxy lever is out of my way when the torch is clamped
next to the pilot.  I don't know what to suggest to you, since your
scenario sounds so similar, and hopefully I'm not overlooking any key
differences.  My initial level-setting procedure for the torch-body
needle valves seems identical to that of oxy/acetylene, I first bring
a fuel-only flame off the tip then add oxy.  Wind is a foe of either
=/
I have a feeling that propane mixtures need a little more "oomph" to
light, something about the fuel being so heavy and syrupy, but I can't
quite quantify that.

Best of luck,

Ben

P.S. - my rig has cut before, and was reported by more experience
hands to be quite capable, and just fine as expected.


On Sun, Nov 8, 2009 at 7:16 PM, Paul N <crosspein at sbcglobal.net> wrote:
> Well, I spent a couple hours messing around with oxy propane cutting
> today, probably ran through 40-60 cu ft of O2.
>
> It took me awhile to get the flame balance to where I could cut (Notice
> I didn't say "correct", as I'm not sure that term would be accurate).
> I have a "clone" of a Victor r100 torch, and was using a #2 oxy/propane
> cutting tip. I was working outside, so there was some wind to contend
> with. I had the propane at about 6psi, O2 at about 25psi.
>
> I had to "ratchet" up to working settings on the torch. If I just turned
> up the propane at the torch, the flame moved away from the tip, and if I
> added O2 at that point until I got a nice clean cone, it wasn't hot
> enough, nor was there enough O2 flow to cut. So I had to alternate: add
> more propane, add some O2, etc. until I got a decent flame.
>
> I was cutting 3/8" plate (cutting a 30" circle to use for a base of a
> legvise mount I hope to build). It took several tries to get things
> acceptable, along with the tip to work distance. Even then, I got some
> occasional popping in the torch. I thought that would be an indication
> of excessive heat, but adding more O2 made it worse, and adding more
> propane made the flame "noisier", and had me thinking it was too high.
>
> It's obvious I need some more practice, and perhaps play around with the
> gas settings some more, as I had to move pretty slowly to maintain a
> steady cut.
>
> Still, every once in awhile, I'd move the torch in a way that would
> result in losing the cone, but not the flame, and I'd have to back off
> the pressure to re-establish the cone. So maybe I had it turned up too
> high. I'll have to spend a little more time with it to get more familiar
> with using propane. It's obviously different from acetylene.
>
> Next step will be "plunging" cut (not starting at an edge) I'm going to
> assume that there's some difference there too, as with acetylene, I had
> actually started to form a puddle before hitting the cutting O2.
>
> Comments and further advice is welcome.
>
> Thanks again everyone.
> **Paul N.
>