[TheForge] Oxy/Propane reprise

[Paul N]

Thanks Ben,
There's no question that the wind was a factor, as the torch blew out a 
few times with a gust of wind. I'm still a little unsure of how my flame 
profile should look. I was setting the mixture so there was little of 
what I would call an "acetylene feather" of I were using acetylene. But 
those cones in the preheat flame were mighty small, maybe 1/8" to 3/16".

I was successful in cutting my circle, I just had some difficulty a few 
times. Actually, now that I gave it some thought, that I did cut about a 
90" long kerf, and while I don't know how fast I was moving, if it were 
about 3 inches per minute, that's still about 30 minutes of continuous 
cutting. And there were segments where I was actually moving along 
pretty well for an inch or two before I got a little ahead of my heat 
and had to pause.

And I know I was going pretty slowly, particularly when I got "near the 
end" and was worried that the change in balance was going to make the 
thing move alot, so I was a little more outstretched, and consequently 
less steady with the torch. (As it turned out, the work was sufficiently 
secure, and as the cut completed, it didn't move much)

It'll be a good week before I get a chance to try again. Gotta devote my 
saturday this week to the UMBA fall meeting. At least I have a more 
manageable piece to practice on now. A 4'x4'x3/8" piece is not that easy 
to move around :-)

Thanks again,
**Paul



Ben Barrett wrote:
> 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: