Shouldn't I be able to get a neutral flame?

squid · #1 2007-02-27, 8:09pm

I have a minor with a Devilbiss 5 lpm oxycon and another 5 lpm oxycon hooked together. I set them each at around 3 lpm to try and get good oxygne purity out of them. I haven't really had any problems with this set-up until I tried working with Van Gogh and DaVinci silver glasses. I was getting a lot of haze on the glass so I read about testing for a neutral flame using a boro rod called Amazon Night. I tested my flame tonight and it shows a definite reduction flame. I tried making many different adjustments - using each oxycon by itself, turning the propane down VERY low on the torch and on the regulator and just could not get a neutral flame.

I don't know what to try next. Any suggestions??

MikeAurelius · #2 2007-02-28, 7:06am

What pressures are you running on your propane regulator? And more importantly, what are the pressure *ranges* on the propane regulator 2nd dial (the one that shows line pressure to the torch)?

When you "think" you have a neutral flame - what do the individual cones look like (colors on the tip and how much of the cone is that color?)

Renee Weaver · #3 2007-02-28, 7:11am

Hi, I have the very same setup and have been playing around with boro. I need an neutral flame too. I cleaned the filters on my oxys and turned up the out take to 4 1/2. I can get my amazon night to show a neutral flame, but I have to turn the NG down. It can get pretty confusing because everything I read about doing boro, they say to turn the torch up to get a really hot flame. But to get a neutral flame, I have to turn the flame to a smaller one and make my beads really close to the torch head. I'd like to hear some advise on this too!
Renee

squid · #4 2007-02-28, 7:16am

I will check the exact pressures tonight, but I did fiddle with the regulator last night to see if that made any difference. The dial on the left was set at 8 or 9 and if I went below 6 or so I got fluctuation on the torch. I don't recall what the dial on the right said. How important are the pressures on the reg when I am adjusting it on the torch?

I can get the cones to be completely blue but the test I did last night still showed that it was a reducing flame. I typically run with about 1/2" candles, with about a fifth of that white/yellow.

squid · #5 2007-02-28, 7:17am

Oh and I did replace the filters last night.

rainygrrl · #6 2007-02-28, 3:32pm

I've run a minor on one oxycon with propane at 5 with no fluctuation. Is your propane tank either very full or close to empty? That's when I've had problems.

Also, I thought I read that a 6:1 oxy

ropane ratio is good for boro. I don't know myself.

rainygrrl · #7 2007-02-28, 3:34pm

I guess colon followed by p gets translated into a smiley lol. What I meant is oxy to propane.

MikeAurelius · #8 2007-03-01, 5:58am

One other thing that's not mentioned in the test from GA -- once you test a section of the color rod, burn that section off and throw it away. Always start fresh.

Try it again with a fresh section of color and see if you still have problems.

squid · #9 2007-03-01, 8:06am

Quote:

Originally Posted by MikeAurelius

One other thing that's not mentioned in the test from GA -- once you test a section of the color rod, burn that section off and throw it away. Always start fresh.

Try it again with a fresh section of color and see if you still have problems.

I did use a fresh piece every time I tested it. I moved down the rod to an unused spot - every single test i did was reducing.

I checked my reg last night and the dial on the left is set at 8 psi and the dial on the right is just below 100 psi. Do I need to change my propane setting?

squid · #10 2007-03-14, 10:52am

I am still having trouble with the silver glasses and am hoping to eliminate a reducing flame as the culprit. The specs for my oxycon say that purity is 95% (+/- 3%) at 4 lpm.

Does anyone know what percentage of oxygen is neccesary to get a neutral flame?

kbinkster · #11 2007-03-14, 11:21am

I'm not sure that purity is the problem. You can still get a neutral flame at around 90% concentration.

If you are running a DeVilbiss (8.5 psi) and another machine (up to 6 psi), you may only be getting oxygen from your DeVilbiss. When you have a big enough difference in pressures, the line will be pressurized to the higher pressure and the lower output machine might not be able to push its oxygen into the line. Since you are only running the DeVilbiss at 3 LPM, you may only be getting 3 LPM to your torch. Don't be afraid to bump up your LPM to 5 on each machine - they will only put out as much as your torch needs. Just don't let the ball go above 5 LPM on either machine.

So, your problem may be a volume problem rather than a concentration problem. But, it would not hurt to run each concentrator alone, get the best neutral flame you can, and and test the flame chemistry again to see if you have a purity problem.

squid · #12 2007-03-14, 12:13pm

The other oxycon I have is this one:
http://www.home-med-equip.com/oxygen...or/irc5xl.html

It is a Platinum XL Oxygen Concentrator w/ SensO2 IRC5LXO2 by INVACARE

it is a 5lpm unit with 5 +/- .5 PSI output.

When I use them together, I set them both the same and then once they are running, I make sure that the "alls" in the flowmeter stay even between the two. Is is still possible I am only getting oxy out of one of them?

Also, I did try each oxycon on its own and still got reduction on my amazon night rod.
I tried them together at 4 different settings and apart at 2 settings each and all of them showed reduction.

kbinkster · #13 2007-03-14, 1:16pm

Setting the flow the same does not set the pressure the same - and Invacares puts out 5-5.5 psi. So, there is a big difference in pressures and yes, you could be getting the oxygen from only one machine.

But, I just re-read your previous post where you describe the candles and say that you can get 1/2" long candles and even when they are all blue, you still get reduction. I can't believe I missed that before! That would definitely suggest to me a purity problem. Is there any place near you that could test your purity for you (like a medical supply place)?

squid · #14 2007-03-14, 2:06pm

After a good many phone calls, I just found someone to test them for me! I will report back

bead crazy · #15 2007-03-24, 12:13am

I don't want to highjack this thread but can someone tell me about the importance of having 2 dials on my propane regulator. THe one I have only has one dial.

kbinkster · #16 2007-03-24, 9:34am

There are regulators that have one gauge (to show your psi setting) and others that have two gauges (one to show your psi setting and the other to show how much pressure is in the tank - an indicator of how much fuel is still in there). If you only have one gauge, that's o.k. You can simply lift your tank and feel aout how much liquid propane is in it and have an idea if you are running low or not.

bead crazy · #17 2007-03-24, 4:45pm

OK thanks On the top of my tank on the turn on handle there is a red and green indicator that tells you how much fuel is left. So my gauges must be adequate. Thanks for the answer I hope you figure out what is going on Squid

squid · #18 2007-03-24, 7:39pm

I am taking my oxycons next week to have the output tested. One of them is less than 2 years old and is still under the original manufacturers warranty and the other was a refurb with a 5 year warranty, so either way, I should be good if they aren't up to snuff!

squid · #19 2007-03-27, 5:43pm

I had my oxycons tested today and the Devilbiss is 95.5 to 96 % from 2 to 4.5 LPM, so very good output.
The invacare is 96.5 to 97 from 2 to 4.5 lpm.

So why can't I get a neutral flame with even just one of the oycons hooked up?

At what setting should I have my propane regulator? Does it really matter if I am controlling it with the torch knob anyway?

Also, they checked the psi of the two units. One is putting out 6 psi and the other 9 psi. What do I need to do to keep one from backpressuring the other? I can tell I get way more flow when I have the two hooked together, so how can I tell if one is back pressuring the other?

jokersdesign · #20 2007-03-27, 8:31pm

The only idea I have is if you know that your amazon night is first rods or if you bought them cheap as seconds?

Seconds are slighty off so your tests might not come out right

squid · #21 2007-03-27, 8:36pm

I was gifted the rod so I don't know for sure, but I believe it is first quality.

kbinkster · #22 2007-03-28, 12:25pm

How close are you holding it from the face of the torch?

squid · #23 2007-03-28, 12:43pm

I tend to work a little further out than most people I have seen on a minor - I would say 4 or 5 inches. I will check tonight.

kbinkster · #24 2007-03-28, 1:12pm

Quote:

Originally Posted by squid

I tend to work a little further out than most people I have seen on a minor - I would say 4 or 5 inches. I will check tonight.

Around 4" sounds good.

When is the last time you cleaned your torch? Sometimes a dirty torch can cause a little reduction. Also, a blockage in the oxygen line can keep you from getting a neutral flame.

The candles should tell the story, though. The shorter they are, the less yellow/white tips they should have. The longer they are, the more tips they can have and still be neutral. On a Minor, though, they cannot be as long as on some other torches without going into a reduction flame.

Some of the glasses like to be worked in an oxidizing flame, so be sure to check with the glass manufacturer as to their recommendation of which type of flame chemistry to use for the particular glass you are working.

One manufacturer, though, recommends turning the fuel pressure down really low. Whatever you do, do not run a lower pressure than your torch manufacturer says is safe for that torch. And, be aware that setting a low pressure can cause your regulator to fluctuate and can shorten its life. You should be able to make the needed adjustments with the valves on the torch. A setting of 5 psi or so is fine for a Minor. From there, you should be able to adjust the fuel just fine at the torch.

squid · #25 2007-03-28, 1:19pm

Quote:

Originally Posted by kbinkster

Around 4" sounds good.

When is the last time you cleaned your torch? Sometimes a dirty torch can cause a little reduction. Also, a blockage in the oxygen line can keep you from getting a neutral flame.

The candles should tell the story, though. The shorter they are, the less yellow/white tips they should have. The longer they are, the more tips they can have and still be neutral. On a Minor, though, they cannot be as long as on some other torches without going into a reduction flame.

Some of the glasses like to be worked in an oxidizing flame, so be sure to check with the glass manufacturer as to their recommendation of which type of flame chemistry to use for the particular glass you are working.

One manufacturer, though, recommends turning the fuel pressure down really low. Whatever you do, do not run a lower pressure than your torch manufacturer says is safe for that torch. And, be aware that setting a low pressure can cause your regulator to fluctuate and can shorten its life. You should be able to make the needed adjustments with the valves on the torch. A setting of 5 psi or so is fine for a Minor. From there, you should be able to adjust the fuel just fine at the torch.

My reg is set to 8 - could that be affecting the flame? I adjust it at the torch, so I don't see how, but thought I would ask.

I do clean the torch pretty regularly - just did it Sunday night in fact.

kbinkster · #26 2007-03-29, 8:28am

Hmmm.

The torch valves control how much oxygen gets through to the torch head. The main difference that the regulator pressure has is that your valves will be more sensitive/responsive with a higher pressure than a lower pressure. How precise the valves are will determine how well you can control the mix at higher pressures.

You can try lowering your pressure to around 5 psi and see if that makes a difference in how well the valves react. I hesitate recommending a lower pressure than that because of the regulator.

Can you get candles with no tips (not at that candle length, but at a shorter candle length)?

squid · #27 2007-03-29, 8:31am

when you say "no tips" do you mean short candles that are completely blue? If so, then yes.

PaulaD · #28 2007-03-29, 10:20am

The GA website states that if you are reducing you need to cut your propane in half.
Paula

squid · #29 2007-03-29, 11:08am

The document I am following on GA's website says to decrease the regulator by half if the surface of the amazon night is sky blue, but mine is not. It is metallic, for which it says to decrease at the regulator by 1/4 lb increments.

I am trying to understand why it matters what you do at the regulator if you are controlling the propane at the torch.

kbinkster · #30 2007-03-30, 9:33am

Well, the lower your pressure setting, the more you have to turn your valve knob to make an adjustment. For torches with poor quality valves, this might be necessary to fine tune a flame.

For torches without the typical control valves - like Herbert Arnolds, where the valves are pre-set at the factory for specific working conditions (not adjustable) and are controlled by a single control knob - adjusting the regulator pressure may be the only thing you can do to fine tune a flame.