oxycon controls or torch controls

[Ian Pearson]

I am a knob fiddler myself but then an oxycon virgin! Sal is right about watching that knobs aren't turned off too tight. They usually are delicate instruments and should be treated with some care. If knobs are getting warm/hot you may have potential flashback situation.

Ian

[julieHB]

I am sorry if I have hijacked this thread somewhat, just thought it appropriate that I let you know the reply I had from GTT, as I am sure there are many Bobcat users who are curious about this too:

"Hello Julie,
What you have heard is not true.  You can run many flame types as long
as you watch for any sign of the flame overheating the torch.  You need
to watch for any specs or tubes starting to glow, this indicates that
the torch is overheating or carbon is starting to buildup.  Nothing on
the face of the torch should ever glow.  The only flame type that will
cause carbon or glowing is a short soft flame.  If you want to run a
soft flame the candles in the flame must be kept at 3/8" or longer, this
will insure that there is no carbon or overheating.  If you want to use
a smaller flame, back the fuel down and adjust the flame with the oxy
valve.  Our Bobcats can get a good small flame by adjusting the fuel and
oxy down, just watch for carbon or glowing and adjust accordingly."

So now we know 

[Redhotsal]

By the way - I do seem to remember that with some torches - can't remember if it's the Carlisle or the Bobcat - think it may be the Bobcat that we were finding at Di Easts that if you run it with a very sharply reducing flame and then turn the propane down you can sometimes get it to flashback. Might just be the design of it.

Don't worry about hijacking - it's good to compare notes on this sort of techie information

[firedinglass]

Everyone hijack away it's all very interesting! Sal I have noticed since seeing other peoples minor flame, that mine was not that great ,which could explain why i feel the need for 2 oxycons..... My minor flame on 1 oxycon is totally different to jolene's for example, very narrow and not very powerful. I find 2 oxycons much better, just a little hot at their present setting. Anyway i've now ordered a mini cc.  I do sometimes make 50mm beads and they take forever and do sometimes crack on 1oxycon and a minor.  I usually reduce by whacking up the propane and working in the farther end, leaving my oxy  valve alone. I'll try a bit of tweaking and see how I go! 

[Carol]

I twiddle both my knobs ( ) constantly on my Minor to adjust the flame but I use tanked oxy. My knobs never get hot and twiddling doesn't appear to have hurt them at all!

[silverlemon]

Ah Sal said everything that I was going to. I would twiddle away to your hearts content, there's no point having adjustable knobs if you're not going to twiddle them.

The valves are only needle valves and work on the principle of the pointy bit on your knob inside the torch seating in it's seat to seal. The only thing that may wear your pointy bits on your knobs are leaving a back pressure behind for too long, and by that I'm talking like turning off the gas and leaving it for many hours or days, that is one of the reasons why we release the pressure at the end of a session. Also over-tightening your knobs will eventually damage them by wearing down the point so it doesn't seal, so hand tight twiddling me dears!

Beware the cobblers 

[garishglobes]

there's no point having adjustable knobs if you're not going to twiddle them

I've heard that before

[firedinglass]

After reading every ones comments and thinking about all the options - i have come to the conclusion that my first oxycon a devilbiss and quite old; was just not that powerful and since i got it a running mate it's made a world of difference.  i worked this afternoon with both turned down to 3.5 and it was much better,  not nearly so hot;  I adjusted both knobs as needed for reducing.