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beakillion
2013-02-05, 10:12am
Can you use a oxycon from a medical supply place for lampworking or does it need to be made especially for lamp working?

kbinkster
2013-02-05, 10:26am
You can use a concentrator from a medical supply place, but you need to remember to:

(1) Keep the valves open on your torch while the machine is running, except for the brief moment it takes to light your propane; and,
(2) Keep an eye on the flow meter ball and never let it go above the LPM rating of your machine.

Raimond
2013-02-05, 11:12am
IF your looking for a OxyCon, you can not buy it from a medical supply outlet without a prescription. You wouldn't want to anyway due too cost. Look on Craigslist, penny-saver, classified ads, yard sales and sometimes E-Bay.

I just got two from an estate sale for a very good price. You must be creative to save money...

Alaska
2013-02-05, 3:25pm
One basic rule of thumb is to keep the ball one mark below the machine maximum. If a 5 LPM machine then set no higher than 4 as an example. The reason is that at higher LPM ratings the oxygen percent decreases. Some of the newer machines have an alarm that indicates low oxygen ratings.

When purchasing used take note of the number of hours on the machine. Some run fine in excess of 25,000 hours while other brands no so much. A machine in the range up to 5,000 hours could be fine for lampworking. Overall less is better.

beakillion
2013-02-05, 4:14pm
Thanks, after checking on lots of machines and warranties, I decided to go with a new one from Unlimited Oxygen.

kbinkster
2013-02-05, 5:00pm
One basic rule of thumb is to keep the ball one mark below the machine maximum. If a 5 LPM machine then set no higher than 4 as an example. The reason is that at higher LPM ratings the oxygen percent decreases. Some of the newer machines have an alarm that indicates low oxygen ratings.

When purchasing used take note of the number of hours on the machine. Some run fine in excess of 25,000 hours while other brands no so much. A machine in the range up to 5,000 hours could be fine for lampworking. Overall less is better.

A machine that is rated for 5 LPM should put out 90% purity at 5 LPM. Above that, it drops off sharply. Concentrations of 90% are actually quite good for lampworking purposes. So, on a good machine, you should be able to run it where it is rated and not have any problems. If you are running a machine that does not put out good purity, then I could see running it lower than its rated LPM.

If a person is buying a machine off of Craig's list or they're picking one up from a friend, or whatever, the hours matter and some machines hold up longer than others before they need to be reconditioned (and reconditioning is more than a quick filter change). If a person is getting a reconditioned machine, then the previous hours on the machine no longer matter.

Alaska
2013-02-05, 5:30pm
Yes you are correct about the 90% rule. However, I like to use oxygen that is a bit better than 90% thus the need to decrease the overall LPM IMO.

The general rule, depending on machine is more or less:

1–3 liters per minute at 95%
4 liters per minute at 92%
5 liters per minute at 90%

kbinkster
2013-02-05, 8:26pm
That's generally how it is supposed to go, but that isn't always how it is out in the field.

My question is this, and I am meaning no offense by it:

When you say that you like purity better than 90%, are you actually testing the purity with an oxygen analyzer and seeing that it is 90% at 5 LPM before making the adjustment, or are you assuming it is 90% because that is how the machine is rated?

I ask this because when I was sending my analyzer out to people to test their machines, there were results coming back that showed that some machines were not putting out 90% purity at the LPM it was supposed to (be that at 5LPM, 8 LPM, or whatever). One brand (actually two) in particular seemed to consistently come back with results below 90%. People thought they were getting 90% but they weren't.

It may very well be that you don't like the product coming out of your machines at 5 LPM (or whatever LPM is is supposed to have 90%), but that does not necessarily mean that you do not like oxygen at 90% purity or that 90% isn't good for lampworking. Unless you test it, you don't know that what you had coming out wasn't 88% and lowering the LPM to 4 was 90%. KWIM?

From what I have tested in my own studio, and I have used an oxygen analyzer to test the output of the machines, 90% purity is adequate for working most glass. It produces good heat and it treats colors well, even oxygen-sensitive soft glasses. (I'm talking about flame chemistry/atmosphere and not size, as that has to do more with the LPMs available than anything else).

On machines with poor purity, the flame is cooler and more reducing. It can take much longer to heat up the glass and it isn't as nice with colors. Running a smaller flame or setting the machine to a lower LPM is the best way to work around that.

istandalone24/7
2013-02-06, 6:22am
not to thread jack, but i've got a question for kim about an ex15.

i use it with a homefill II system to fill a k tank. last night (overnight while it was running) it got cold in the cellar....so cold that the o2 purity dropped too low and the homefill shut off. no big deal, but my oxycon kept running all night with no outlet....these homefills don't have a relief valve if they shut off the oxycon's oxy has nowhere to go.

what would i look for/what symptoms would the oxycon have if it's messed up from running with nowhere for the o2 to go?

kbinkster
2013-02-06, 9:00am
Cold air is denser, so usually, that means better purity. It could have shut off because it was just too cold for the concentrator's compressor to run (30-40 degrees for some machines).

I don't know if the EX15s have had their alarms disabled, but many machines will alarm and/or shut off when they are backpressured to protect the sieve beds from backflow. It could be that yours shut itself off before any damage was done. Also, some machines have a backflow prevention valve inside between the holding tank and the outlet. That could also prevent backflow into the sieve beds. Hopefully, your machine has some of these fail-safes in place and nothing was harmed.

EDIT: I re-read and saw that it did run all night. :( Check for sieve dust as described below.

That being said, assuming that it turns back on and runs, what you would look for would be pulverized sieve material (sieve dust). It's a fine white powder. Whenever you see that, regardless of a Homefill incident, you should be concerned. It can be caused by excessive vibration, backflow, and too much flow/pressure air going into the sieve beds (like more than was intended by the original manufacturer) from the compressor. Not only can it indicate a problem with your concentrator (and contribute to poor purity), that stuff can go through your lines and get into the valves on your torch and mess it up (and possibly through the torch and onto your glass).

Check your concentrator outlet, your lines, and your connections, especially at the connections where they go in and out of your fill station and the inlet barbs/studs on your torch.

istandalone24/7
2013-02-06, 9:28am
thanks i'll check into the sieve dust.

i know this oxycon has no alarm or valve on it.
now this oxycon makes a strange noise. instead of the "hissing" you normally hear....it sounds like it's under a load....one "cycle" sounds normal but the other cycle sounds very strange. i guess i'm taking it apart lol.

istandalone24/7
2013-02-06, 9:41am
on one of my oxycons, there is some of that white dust you described. it's mostly around the filter in the back (the one you have to open the machine to get to). this is a different one that was hooked to the homefill, it's the first one i bought back in april of last year, and the white dust has basically been there since i rec'd it from abr.

kbinkster
2013-02-06, 10:04am
Are your machines still under warranty?

istandalone24/7
2013-02-06, 11:51am
i doubt it. i got the two ex15's from abr scratch and dent last april or thereabouts, and i've got a mini15 that jack gifted me in return for a review on the product.
i've got a guy i know that lives about 30 minutes drive north, he's familiar with these and modifying/repairing them.