Strange Torch Issues

TheZedWord0920 · #1 2008-01-10, 2:35pm

What's going on when one's flame rapidly changes sizes when one has plenty of oxygen and propane and they aren't touching the little knobs?
It's like an invisible hand is turning the oxygen off.

squid · #2 2008-01-10, 2:40pm

could your oxy regulator be bad - are you on tanked oxy?

Emily · #3 2008-01-10, 3:18pm

Are you really in Georgia? Sometimes people have trouble with their flames surging when the propane regulator gets cold. Are you having particularly cold weather there? Some people have rigged up light bulbs to hang fairly close to the regulators to keep them kind of warm. I have a microwaveable heating pad that's really just a canvas bag filled with something that I strongly suspect is rice (sure feels like it) that I will warm up and wrap around the regulator on really really bad days, but I don't often use it. (I'm in Pennsylvania.) If your problem has been occurring on unusually cold days, think about working out some way to warm your regulator a little bit. Obviously, it should be some way that doesn't pose a fire hazard.

I've read (here) that the propane regulators that most of us use aren't designed to be used at the very low pressures we use, and so don't hold the pressures very reliably. Whoever said that recommended setting your propane slightly higher if you're having a problem. You could try doing that and seeing if it helps.

Trey Cornette · #4 2008-01-11, 5:20am

Did you just hook up a fresh tank of propane? On one occasion I got a tank of propane from an exchange a tank kind of place that had a faulty safety valve that caused my torch to rapidly fluctuate. I took the tank back, got another and that fixed the problem.

Wonker · #5 2008-01-11, 5:58am

could you have a leak in a supply line? It sounds like you're having a problem that relates to steady pressures to the torch so it's either in the tank (no gas), the regulator (sometimes really low settings on regulators make them act odd) or in the supply line. The pressure side of the regulator should tell you whether there is gas in the tank or not....good luck and I'd be curious to know what you end up finding as the problem. (I'm in roswell....nice to meet you)

Cosmo · #6 2008-01-11, 8:01am

Maybe your torch is haunted...

TheZedWord0920 · #7 2008-01-11, 3:54pm

I think it's that last one...

I dunno, I'll have to go check everything out. My dad's been setting it all up, so I'll have to wait until he can help me.

stephaniemaddalena · #8 2008-01-11, 11:24pm

I've had this problem for 2 reasons. Sometimes the diaphragm in the o2 tank is faulty. What type of torch are you using? I'm finding wild fluctuations with a new type of torch I have.

maddog1050 · #9 2008-01-17, 11:42am

Does anyone know the average lifespan of a propane regulator? I've been getting a fluctuating flame recently and found this thread. My propane is outside with a bucket over the regulator. I know--I probably need to devise a better shelter for it. My regulator is at least ten years old.

Maybe time for a new one?

Mark Parkinson · #10 2008-01-17, 3:07pm

Sometimes when the pressure is set too low on a single stage regulator they start to "hunt" the gauge sets the pressure and off it gos down the line and the pressure drops and the gauge can not compensate for the low pressure and surges to bring the pressure back to the setting this starts a vicous cicle that results in fluctuations. the easy fix is to set your pressure a little higher on your gauge and manage the mixture at the control on your torch, or get a two stage regulator which is designed so this does not happen ( about 40-50$ more than single stage regs), or you can get regulators designed for low pressure (very expensive)

Laurawl · #11 2008-01-18, 8:41am

Quote:

Originally Posted by Mark Parkinson

Sometimes when the pressure is set too low on a single stage regulator they start to "hunt" the gauge sets the pressure and off it gos down the line and the pressure drops and the gauge can not compensate for the low pressure and surges to bring the pressure back to the setting this starts a vicous cicle that results in fluctuations. the easy fix is to set your pressure a little higher on your gauge and manage the mixture at the control on your torch, or get a two stage regulator which is designed so this does not happen ( about 40-50$ more than single stage regs), or you can get regulators designed for low pressure (very expensive)

Hi Mark, I have a torch that the flame is constantly getting smaller and smaller, but there is plenty of gas in the tank. I have levt my tank and regulator outside uncovered for four years. I am afraid I've ruined my regulator. I want to buy a new one but can't decide if I should buy the single stage @ $100. or the two stage @ $200. Is it worth the extra $ to buy a two stage? Thanks! Laura L

kbinkster · #12 2008-01-19, 3:20pm

OP, are you on tanked oxygen, or a concentrator?
What psi setting do you have for your oxygen (if on tanked) and propane?
Where are your tanks?
How old are your regulators?

Mark Parkinson · #13 2008-01-20, 1:10pm

Quote:

Originally Posted by Laurawl

Hi Mark, I have a torch that the flame is constantly getting smaller and smaller, but there is plenty of gas in the tank. I have levt my tank and regulator outside uncovered for four years. I am afraid I've ruined my regulator. I want to buy a new one but can't decide if I should buy the single stage @ $100. or the two stage @ $200. Is it worth the extra $ to buy a two stage? Thanks! Laura L

Laura
If you already have a two stage I would take it to your local welding supplier they can often do rebuilds for $40-50. I prefer two stage regs myself I use them on my oxy-act tanks my propane tanks and my mixed gas tanks for mig and tig welding they have the advantdge of balancing your hose/torch demand with the available tank presure and stop the "hunting" that can sometimes happen at low pressures. That being said if I had to leave the gauge and tank out side in the weather I would have to think seriously about using a single stage and replacing it every couple of years or so, you could slow down the weathering by putting a plastic garbage pail over the set up when not in use.
I have a bottom vented "shed" outside my smithy that I keep my tanks in and run the hoses through a small door in the wall. I also have small secondary gauges on my welding tables to fine adjust the hose pressure, I have not yet added this to my glass torch set up ( but I haven't yet settled on the torch I want)

is the flame getting smaller as you go along in one torching period? or is this over a period of time (weeks) if its in one torch period I would look at the tank and see if it is frosting up. A tank can do this in cold weather and cause a drop in pressure. Preasure in a propane tank is cause by the liquid propane "boiling" off into a gass form that process chills the liquid ( equall and oposite reactions) and results in the chilling of the tank when the liquid chills too much this inhibits the gassing process untill everything warms again. If it is over a period of weeks that your flame is getting smaller I would have your regulator checked.
In my blacksmithing forges I have three 1" burners and running these flat out ( to heat large pieces) I can turn two maifolded 100# tanks into icicles in 30 mins, even on a hot august day I can end up with 1/4" of ice on the outside of the tanks very quickly