oxycon controls or torch controls

firedinglass · March 05, 2009, 08:48:45 AM

I have 2 oxycons which is great but sometimes the flame is just too hot even if i work far out in it and makes some glass bubble.. My oxycons are set at 4.5 and balanced. Most of the time I work with the oxyvalve on the torch almost fully open as I read somewhere that it was very wearing on the knob to keep adjusting it, so i only turn as is neccessary and tend to adjust propane more. i can't decide whether it's better to reduce pressure on oxycons to maybe 4, so that the flame isn't so fierce or to just twiddle as often as i like with the oxy knob on torch - which do you think $:-\$

Kaz · March 05, 2009, 08:51:24 AM

I work on 2 oxycons but have them set on about 3.
I often twiddle with my knobs. If I want to reduce I always turn oxy down rather than propane up.
Kazx

garishglobes · March 05, 2009, 08:59:36 AM

I'd have thought both torch knobs were there to be fiddled with? Would the oxy one wear any quicker than the propane one? I'm on one oxycon, but I do tend to turn the oxy down if I want a reducing flame - its hard to see how to do it otherwise..

And on a less serious note...
Its so tempting to be smutty now

Mary · March 05, 2009, 09:09:34 AM

I don't touch my oxy knob at all, it's not good for your oxy-con to block the line for any length of time. I reduce by whacking my propane right up.

If I wanted to turn my oxy down for longer than reducing, I'd turn both down at the machine, that's what I did when I was getting used to two.

garishglobes · March 05, 2009, 09:12:19 AM

Oh, now I'm just plain confused. Mary, do you have a different oxycon to me? I never touch the settings at the oxycon because I was told never to fiddle with them! I always use the torch controls.
When I use soft glass, I have the oxycon at about 3 1/2, but again controlled at the torch. Am I ruining my oxycon then?

Mary · March 05, 2009, 09:24:10 AM

If you're using one oxy-con you want it on max, but you can set it too high, so "find the optimum setting then don't fiddle" is reasonable advice. But you won't hurt the machine by changing the dial, it's what it's meant to do.

I was told you can cause problems by switching off at the torch, it doesn't like back pressure. Though I imagine there is a safety system, so I can't see it would cause actual harm.

firedinglass · March 05, 2009, 09:26:57 AM

Hi Mary, that's what i seemed to remember reading..... think I might just turn down at machine a little as presumably if machines are working properly 2 oxycons would be putting out 9lpm when 7 or 8 would be more than enough for soft glass ( i don't ues boro)

julieHB · March 05, 2009, 09:49:57 AM

Just to throw something else into the equation - I mean to have heard/read somewhere by someone (could it have been Corina?) that it is not good for the torch to run on low gas flow for any length of time, and that one should not bring the flame down to a pinpoint for very long, i.e. when doing stringer work. Is this correct?

Mary · March 05, 2009, 09:55:29 AM

Julie, I'm not sure, though I know that one torch (is it the mini CC?) is known for getting hot knobs if it's run too low.

julieHB · March 05, 2009, 10:13:08 AM

Thanks, Mary, I might just have to send the GTT boys an email :-)

garishglobes · March 05, 2009, 10:21:00 AM

I've heard that too, Julie - in fact I think it says so in the manual for the torch (which I actually read!!!) - mine's a Bobcat, but its not had hot knobs yet (I'm obviously just not exciting enough..

)
Probably being on 1 oxycon, I'm fairly safe having found a reasonable pressure and leaving the oxycon dial? I can see turning the oxy at the torch off being a problem with backflow, but would have thought that turning it down for a few moments to reduce was ok..? From my reading of the torch manual, it doesn't like being run at a small flame for any length of time at all, but then, a reducing flame isn't that small, it is just less oxygen-rich.

julieHB · March 05, 2009, 10:36:43 AM

Hi Emma, is that the one-page Instructions for Bobcat Users you mean, or do they have a "proper" manual? It says they recommend to not run flame lengths of less than 5 inches until you are more experienced, as it can overheat the burner if not adjusted properly (it doesn't say what the proper adjustment is, though... )

Anyway, I have sent them an email, let's see what they say

~~I have~~ my torch has never had hot knobs either

garishglobes · March 05, 2009, 11:05:30 AM

Mmm, I was using manual in the broader sense...

I've lost it now, but I think it was probably the one-page job

I'll be very interested to see what they say!

Redhotsal · March 05, 2009, 12:10:54 PM

Wow - this all sounds really complicated. Just butting in with my pennies worth though...
If you aren't using boro I can't really see why you would want to run two oxycons? Surely one is enough? If you are making medium sized beads (3cm diameter and downwards) wouldn't 5l/min be suffient? It certainly is with a minor burner - though I can't speak for other torches.

Just my experience with a minor burner - I've had the same one for eight years. It's been fiddled with, the knobs are constantly being adjusted and it's had a fair amount of abuse as I use it as my main teaching torch. It's a great torch - actually. Even if it fell apart tomorrow I would have had my moneys worth five times over. In the case of the minor burner there is absolutely no problem adjusting the knobs to whatever you want. Can't speak for the other torches but wouldn't have thought they would be a heck of a lot different, though if you are getting hot knobs on a torch for whatever reason I would really question the safety of such a torch. If the knobs get hot then the heat would spread to the body of the torch and then to the hoses. Not good. That's why the minor has a heat sink to disippate the heat - and it shouldn't be taken off. I would question whether a surface mix torch should get hot at the knobs - bad design.

I do know that if you turn the knobs off too tightly at the end of your session that will eventually damage the torch so that should be avoided.

Regarding the oxycon - they do seem to have their individual foibles. I used to leave on of mine chugging away happily again a closed oxygen valve on the torch which I went off to make a cuppa and it always seemed to be fine but I have worked with oxycons which will actually shut down if if left running against a closed oxygen valve. I would say that to be on the safe side I would always open the oxygen valve if the oxycon is working. But don't forget to turn the torch oxy valve off momentarily before lighting the propane!

Also - it does seem to be that if you turn the oxycon on fully you'll probably have problems with it shutting off. I tend to run mine at 4.5 litres to be on the safe side. But again this does seem to vary in individual oxycons.

Kaz · March 05, 2009, 12:15:48 PM

I run on two oxycons on a Lynx but also ran the minor on two oxycons as well for a while. But I like hot as I am always in a hurry! My first oxy was very poorly before and constantly underperformed and switched itself off from time to time. Since I got it a mate and run them both at a lower level, it is very happy!
Kazx