Using an Oxygen Concentrator for Soldering

Last updated:  10/1/21, 10/10/21

Nancy LT Hamilton

Please see my Disclaimers page.

I’m working on a video, now, about setting up and using the Oxygen Concentrator.  I’ll provide the link as soon as the video is live.  

I recently changed my soldering system.  After extensive research, I decided that it was too dangerous to keep my acetylene tank in my studio.  I was going to switch to a (supposedly), safer propane system but, nixed that after learning how dangerous that could be (see my torches page).

    I decided to go with an oxygen concentrator and a 1 pound disposable propane tank (like the kind used for camping).

The Oxygen Concentrator

I purchased a refurbished concentrator (5 LPM) from Rio Grande (which is, as of this writing, out of stock).  There were no instructions included on how to use this machine so, it took me a little while to figure it out but, I did and so far – it works great!

Stuller also sells an oxygen generator:  the Ready-OX Oxygen Generator.  “The Ready-Ox System includes the oxygen generator, a genuine Smith Little Torch with eight-foot hoses, 5-tips (sizes 3 through 7), regulator for disposable propane tank, propane tank bracket, spark lighter, reverse flow safety check valves, and step by step set-up and operation instructions.”  It costs about $800.00 as of 10/10/21.

High Volume Oxygen, on YouTube, has a video on how to hook up their Pro Gen 10 oxygen concentrator to a Smith Little Torch.  Note that their concentrator is a 10 LPM, for those needing greater pressure. You could also run up to 4 torches off of it. This could be a good concentrator for jewelry schools as well as for personal use.

If you are adventurous and want to make your own, here’s a video to watch.  I haven’t done this so, not sure.  Just thought it would interest you!

Ever wanted to tear apart an oxygen concentrator and see how it works?  Well, here’s a video for you!

If you want to know how an oxygen concentrator works, check out this video, below.

It’s impossible for me to convert LPM (Liters per minute) to PSI (Pounds per square inch) so, I cannot tell you how many PSI are being produced when the concentrator is at 1, 2, 3, etc. LPM. I’m over my head here but, I found this concentrator that had PSI information.  Do I assume that a 5 LPM system has about 1/2 the PSI of a 10 LPM (5.8 – 11.6 PSI)  concentrator?  If so, would that mean that a 5 LPM concentrator produces 2.9 – 5.8 PSI?  I don’t know…

  After I made and posted this video below, I found out that the ball didn’t move because the oxygen valve, on the torch, wasn’t open.  It moved just fine after I did that!  So, don’t think yours is broken if it doesn’t move!  Just open the value and you’ll see what LPM you are at – whatever that means.   I don’t know the PSI but, the pressure is sufficient to power up my #7 tip with a nice, hot flame.

One bitch, besides the lack of instructions, regarding the concentrator is the noise level.  It’s pretty annoying.  Although, given a choice between being slightly put out by the noise and potentially killing someone or blowing up my studio, I’ll take the inconvenience!   I live in an area that has wildfires and I worry about storing explosive gases in my studio.  When one is evacuating, you don’t want to have to think about removing all of your explosive gases – especially a heavy acetylene tank!  Not only that, I need to think about the safety of our first responders like the fire department and police.  Also, having an acetylene tank go off during a fire, would certainly guarantee that my studio didn’t survive!  So, I will put up with the noise – it’s worth it.

The dangers of oxygen – even though it’s not flammable!!!

Oxygen is NOT flammable but, oxygen makes fire burn hotter. Oxygen is also an oxidizer.  Oxidizers intensify combustion.  Oxidizers also widen the flammability range of flammable gases and liquids, and lower the flashpoints and ignition temperatures of combustible materials so, that these materials are more likely to ignite.

The Firefighter Insider has some scary videos on oxygen combustion and a lot of good information on oxygen safety.  Watch this video on what oxygen can do to a flame!

Some information about propane

Propane should never be stored in a home, basement, or attached garage.  See Propane 101 for information on propane storage.

Never refill small propane cylinders like the 1# tank or the smaller 14.6-ounce bottle. Refilling these containers is against federal US law and comes with a $500,000 fine and up to 5 years in prison.

One way to protect yourself is with a propane leak detector.  Be sure the detector is installed near the floor., as propane is heavier than air and, therefore, it sinks.

I found this video on removing the gas from a 1# cylinder so that it can (hopefully) be taken to a recycling center.  I have not tried this.  I would only open remove the valve thingy outside and away from any potential flame source.

A tool similar to what he mentions in the video, the core removal tool, can be found here.

 The Torch

    I am using the Smith Little Torch with the concentrator.  These instructions are specific to it.

The Little Torch requires a very low PSI level.  The highest PSI for their largest standard torch tip (a #7) is 8 PSI for both the gas and the oxygen.  Below, is the chart from the Little Torch’s instruction manual.  The #2 tip can only be used with acetylene or hydrogen. I find the #3 tip a real pain in the tush because they are so hard to keep lit.

There are other types of micro torches you can check out here, on my Torches page.  I am not sure if they will work with the oxygen concentrator.  You want to ensure that the PSI required isn’t greater than the concentrator can produce. With these micro torches, I would be surprised if they didn’t work with the concentrator but, be sure and contact the manufacturer!

Flashback Arrestors

Check valves will NOT stop a flame.

From years of testing, many professionals have found that flashback arrestors and check valves are not necessarily necessary if all safety practices are followed.  Things like draining your hose, opening the baffles on the regulators, and turning off the gas pressure at the tank, when shutting down, do much to reduce potential dangers.  Checking hoses, not using broken regulators, storing your tanks correctly, keeping them free from dirt, oil, and grease – all these practices and more will help reduce the dangers of operating a torch.  Remember, most injuries are caused by operator error, through either a lack of training, negligence, and/or neglect, etc.  That said, you probably want to have flashback arrestors installed.

See the Harris Group’s commentary by David Gailey.

With most torches, it is ideal to have the flashback arrestor between the hose and the torch handle. Placing the arrestor at the back of the torch will protect you the most as it will stop the flame from entering the hose and it will also not allow the gases to mix.  With the Smith Little Torch, attaching the arrestor to the torch handle is not possible so, the flashback arrestor needs to be placed at the junction of the regulator and the hose – a regulator mount.

If you are using a portable gas tank, you’ll have to attach the flashback arrestor between the “regulator” and the hose.  The “regulator” with portable tanks is not like a normal regulator.  It is more of just an adapter that helps you to hook up your Little Torch with a disposable tank.  They cost way too much money, for what they are.  I looked everywhere to see if flashback arrestors were needed for portable tanks and O2 but, found nothing.  So, as of now, we will leave this unanswered!

Starting out with an oxygen concentrator

Little Torch with disposible adapters

If you are starting out fresh (or for the first time) and you are using an O2 concentrator and a disposable propane tank, I recommend the Little Torch that comes with disposable tank adapters. If you buy the regular setup, you’ll have to purchase the disposable tank adapters separately (if you can even find them) and I think they are around 85.00 each, in some instances.  Cyberweld was the cheapest at about $75.00.  Gentec sells both for about $110.00 on Amazon.  Amazon also sells the adapters separately so you don’t have to buy both but, dang!  They are pricey – $75 – $90 each!  You don’t need an oxygen adapter for the concentrator as the Little Torch screws on directly.  If you have the Little Torch with the portable adapters attached, just unscrew the oxygen.  Save the adapter though!  You might need it someday!

Be sure to check out my Q&A Torch page, my Torch page, and my page on gases.  Lots to learn!

Thanks for stopping by.