Correct propane/oxygen balance

vicki · #1 2010-01-31, 3:53pm

I think I am having problems getting the correct balance of propane and oxygen on my Nortel Minor Torch. I also use an oxygen concentrator. The problem I am having is that I am getting black sooty looking lines or spots on my beads sometimes. I try to turn the propane down some but when I do that it seems to take forever to melt the glass. Can someone give me an idea what to try to correct this problem?

FiredDesires · #2 2010-01-31, 4:20pm

If you check out the Nortel site I think they give the optimum pressures for the minor. I always ran mine at 4-6psi propane and 8-12 for the oxy, and just turned down the propane when I hooked up to the concentrator...hopefully somebody running your set-up will have the definitive answer. Make sure your glass is clean and keep turning down the propane pressure till you find what works for you until somebody else chimes in.

vicki · #3 2010-01-31, 4:33pm

Thanks so much.

chrisann · #4 2010-02-10, 5:46am

Vicki
If you are on a concentrator check what the flow meter is saying. If it a 5lpm machine and you are running it near 5 you may not have enough purity in your oxy. I found my 5lpm machines worked much better at around 4.
HTH
chrisann

Dale M. · #5 2010-02-10, 8:19am

And try to acquire a flame that looks like this....

Its pretty close to the perfect neutral flame....

Dale

turtledove53 · #6 2010-02-10, 8:29am

Quote:

Originally Posted by Dale M.

And try to acquire a flame that looks like this....

Its pretty close to the perfect neutral flame....

Dale

Thank you so much for posting this picture! It is helpful to all of of newbies that are not sure of what a neutral flame is!

gemsinbloom · #7 2010-02-10, 11:46am

Great picture! My cones are about 1/4 of an inch but in the picture they look larger. Should they be about 1/2 an inch?

Quote:

Originally Posted by Dale M.

And try to acquire a flame that looks like this....

Its pretty close to the perfect neutral flame....

Dale

LyndaJ · #8 2010-02-10, 2:43pm

With one concentrator, you will have shorter candles. It's the color that's important.

With two concentrators, you will have candles that are more in the 3/8-1/2 inch - and the extra heat to go with it.

gemsinbloom · #9 2010-02-10, 2:45pm

Oh I see, you have been very helpful today Lynda, thank you.

Quote:

Originally Posted by LyndaJ

With one concentrator, you will have shorter candles. It's the color that's important.

With two concentrators, you will have candles that are more in the 3/8-1/2 inch - and the extra heat to go with it.

dragonfly designs 56 · #10 2010-02-13, 3:10pm

how long should your flame be? candles 1/4 inch, or doesnt it matter as long as the candles and flame are blue?

divelement · #11 2010-02-13, 9:46pm

Back when I used soft I had this issue with 104 Moretti glass. Once I switched brands I never saw the black lines again. Moretti clear is crap.

kbinkster · #12 2010-02-23, 12:00pm

If your cones, or candles, are 1/4" long, you only want very small tips. If they are shorter than that, you will want no tips at all.

A typical neutral flame for soft glass beads has candles that are about 3/8" long with tips that are about 1-2mm. The candles can be longer or shorter, and the length of the tips will correspond to the length of the candles.

The more fuel heavy the mix, the longer the yellow/white tips will be and the more reducing the flame will be.

The more oxygen heavy the mix, the shorter the tips will be (no tips is really oxidizing) and the more oxidizing the flame.

speedingpullet · #13 2011-07-16, 9:52am

Thanks so much for the photo! Its really helpful.

I'm still adjusting to using a Minor torch after using a Hothead, and have already turned a rod of delicious strawberry pink glass into grey by having my oxy/propane mix wrong

CD Lampwork · #14 2011-07-16, 9:58am

A dirty little confession on my part: I use to have this problem early on in my lampworking learning curve. Everything would be great, then the dreaded black haze, lines, etc, turn down the propane, took FOREVER for the glass to melt. Problem? Not enough ventilation. Once I kicked the side door or window open it was like night and day. Don't beat on me, I've got great ventilation now. Just my young and foolish days.

speedingpullet · #15 2011-07-16, 11:28am

Yeah, I'm actually radically re-thinking the position of my torch table... I work in my garage with both the doors wide open, but I'm well inside and away from the breeze.

Thanks for the tip! I'll see if getting more airflow over the torch will help.

JEK3 · #16 2011-07-17, 6:35am

I sometimes get soot if I get too close to the torch. I'd recommend working a little further out than where Dale's photo shows (try the 2-3 inch range) and see if that helps.

nana · #17 2011-07-17, 9:46am

I read your reply mentioning "2 concentrators". I have the chance to get another one at a good price.But I have some questions .
1. How do you hook them up ???
2. if you have 2 machines ( each at 5lpm) that won't double the O2 pressure right?
Is there a thread talking about 2 concentrators ???
my Internet skills are zilch .. so I apologize in advance

speedingpullet · #18 2011-07-17, 10:30am

Quick update... I moved my torch table to be nearer the open air, rejigged my oxygen/propane mix to be more oxidising and experimented with working higher up in the flame.
Happily - my clear is no longer smokey and I'm finding it much easier to control the glass! Thanks so much for the advice

ArtcoInc · #19 2011-08-14, 3:05pm

Every fuel has a specific amount of oxygen it wants to burn completely. This fuel/oxygen ratio changes depending on the fuel (propane, butane, natural gas, etc). For propane, this ratio is about 1 to 4.5 (by volume)

This means that you need 4.5 liters of oxygen for every liter of propane. If your oxycon can only put out 5 lpm of oxygen, you can only burn about 1 lpm of propane, and still keep a neutral flame. Add any more propane, and you're going to get a reduction flame.

This is true regardless of what torch you have.

This also means that, if you have a small oxycon, there is a maximum flame size you can achieve, and still maintain a neutral flame. If this flame size is too small for what you are trying to do, you're going to have to get more oxygen. Otherwise, if you try and make the flame larger, you will get a reduction flame (which is cooler than a neutral flame), and possibly introduce soot into your glass.

Malcolm

cheng076 · #20 2011-08-15, 9:57am

nana,
Typically two oxycons are hooked up by hooking the hoses together into a 'Y' connector. Having 2 machines doubles the capacity (liters per minute) but the pressure will remain about the same. Two units rated at 5 lpm and 5 psi will give you almost 10 lpm but still about 5 psi. And yes there is a hugh amount of info on using oxycons on the forum; try searching for 'oxycon hookup' etc.