[TheForge] Oxy/Propane reprise

[Paul N]

Since I already had the torch angle at a "push" angle of about 20 
degrees, I'm going to assume that torch was too far away, and probably 
in need of adjustment.

I had read on some mailing list somewhere (while trying to get as much 
info on this as I could find) that the secondary flame envelope on 
oxy/propane was hotter than the primary, so keeping the torch further 
away (up to a point) was better than up close. I guess that's what I get 
for trusting internet wisdom :-)

Too bad I have class tonight. I'd love to play with this when I get 
home. But we're TIG'ing Al, and I find that great fun too, but I'll be 
glad when the semester is over. I didn't get into the next session 
(filled), and I'm not spending enough time with my hammer.

**Paul

Peter Fels & Phoebe Palmer wrote:
> Paul:
> That travel speed was much slower than it should be. Try tilting the tip 
> in the direction of travel once the cut is started.
> Adjust the torch when the oxy lever is depressed. There should be little 
> or no feather. Crank the preheats up so you can proceed faster..go as 
> fast as possible without losing the cut.  pf
> 
> Paul N wrote:
>> 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:
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