Thread: "Cheaper" oxy-acetylene

I converted to Oxy LPG about 2 years ago at work to half the bottle rental hassle.( Don't deal with CIG/BOC as they are complete bums with customer service and the way they act and behave with charging and accounting on the hire bottles the are a one sided law to themselves)
I managed to buy everything I needed to replace my Old gear from a shop that was closing down.
In the real world with correctly adjusted flame and correct tips on the old comet 3 system the LPG cuts , heats metal just as good as the old set up using acetylene.
I have cut mild steel 6 inches thick without problems and can heat and bend the same using a heavy duty large LPG/oxy heating torch.
The old comet 3 gear is easily converted, but you need a little bit of practice in adjusting the flames with the different fuel.
I use a barbeque bottle for the LPG and strap it in where the Acetylene bottle used to go.
I am able to easily refill the LPG bottle from a bulk supply I have access to.
The only draw back I can find is the old flint gun will not work, you must use a cig lighter .

Ron, where do you get oxygen refills from?

Originally Posted by p38arover

Ron, where do you get oxygen refills from?

Gasweld do Oxygen now. You buy a full bottle & then when it's empty, you can do a changeover at one of their stores.
Tools | Trade Tools | In-store or Tools Online | Gasweld


I have my Argoshield through them now & will be getting the Oxy once my shed is up.

I work for a major gas supplier, so this thread interests me, and I feel I have some points to offer.
Happy to discuss any finer points, dispel any myths, or offer advice where needed, via PM. Don't be shy, happy to help if needed.

Originally Posted by p38arover

Yes, oxy-propane would probably be hot enough for what I do, i.e., silver soldering or brazing. Propane alone just isn't hot enough for silver soldering anything with a bit of mass.

General rule of thumb is that you can cut, braze and solder with oxy LPG. Welding is not recommended.

Originally Posted by p38arover

Hmm, I wonder if BOC still service CIG Comet systems, e.g., tips.

What about my regulators? I guess the oxy one will be OK but I'd need a new propane reg - or do they not use one? That reduces the bottle hire if I don't have acetylene.

I've not investigated oxy-propane.

I assume my cutting gear won't work with oxy-propane.

Most gas suppliers do not service gas equipment, mainly due to their defined lifespan stipulated by Australian standards and enforced by workcover(NSW). Parts, if available are generally not econonical to replace by a gas fitter, as new units (with warranty) generally come in cheaper.

To convert Oxy DA to oxy LPG, you need the following:
-LPG regulator
-Oxy LPG hose (different rubber formulation to prevent deterioration, and correct Australian standards colour)
-Cutting / welding tips to suit.

Originally Posted by p38arover

I just had a look, BOC make an LPG upgrade kit that costs $330.

Last time I checked, full Oxy LPG kits were under the $400 mark. New blowpipe, cutting attachement, tips regs, everything.

Originally Posted by p38arover

My regulators are CIG Monitor 2 units like this:

Jesus, you must love antiques!
With old regs, remember best practice to leak test everything before commencing work. Acetylene in particular has a very low LEL (lower explosive limit) which will create explosive environment if left to accumulate (during a lunch break for example).
Also keep in mind HP oxygen can cause combustion of oils and greases without the presence of a flame. I rmember seeing a safety bulletin of a mechanic who dialled in a reg which was leaking from the HP side of the diaphraghm. His hands were covered in grease, the oxy ignited the grease, and his hand was burnt beyond recognition. Not many people know this fact about oxygen, so keep safe guys.

Toxic, any views on the likes of multiplaz. Saw some light fab work at AllTools and the welds looked good.

Originally Posted by workingonit

Toxic, any views on the likes of multiplaz. Saw some light fab work at AllTools and the welds looked good.

Mate, to be honest I've never even heard of this product before. The concept is not new (plasma cutting / welding) but having it so portable is rather novel.
I looked thru their website, and some of the statements are worded a bit funny, devoid of any real substance regarding what is actually happening during the 'welding process'.
"MULTIPLAZ-3500 provides also an ecologically friendly metalworking method that does not involve either combustion process itself nor combustible materials. No noxious poisonous gases like propane, acetylene, nitrogen, and etc are employed. Moreover, the atmosphere inside working space is enriched with oxygen when device is in use.
Thus, the unprecedented ecological compatibility of this plasmatron makes it possible to perform operations in enclosed spaces without ventilation like offices, premises for living, pipes, shafts, wells, tunnels, basements and etc."


Nevertheless, It looks to be a good product for certain applications, probably not the process that will replace MIG/TIG in heavy fabrication, but otherwise a good process for those guys at home who want to stick 2 bits of metal together without having a primary concern for longevity of the repair.


On first look, it just appears to be a plasma heat source to take the place of gas welding, brazing and soldering, while being able to plasma cut. This is not to be confused with arc welding, which is a whole different process.

In arc welding, the presence of oxygen (which this product purports to produce) leads to weld porosity and contamination of the weld. So not sure how it would perform on a structural fabrication job or heavy repair.

Originally Posted by p38arover

My regulators are CIG Monitor 2 units like this:

Those regs were great,we found they were very rarely damaged.The later ones with the guages sticking out are easily damaged.You can get protection covers for the later ones but the guages still seem to get damaged doing service work.

As others have said,be careful with them as they are very old,the rubber components may be perished..Someone also told me you are not actually allowed to use them anymore,but i can't remember who or why(seniors disease)

Originally Posted by scarry

Those regs were great,we found they were very rarely damaged.The later ones with the guages sticking out are easily damaged.You can get protection covers for the later ones but the guages still seem to get damaged doing service work.

As others have said,be careful with them as they are very old,the rubber components may be perished..Someone also told me you are not actually allowed to use them anymore,but i can't remember who or why(seniors disease)

Gauges are replaceable items (generally <$20), but are usually damaged by ham-fisted numpties who like dropping cylinders. With proper care, any reg will die well after its lifespan according to our mates at workcover, but in a workplace, using gas equipment after that date is a risk to their own.
When you pull a gauge apart though, there is only a small bourdon tube which separates 20 bar pressure from the outside world. Obviously a hard life on the back of a fridgie's ute, or dragged under houses to repair plumbing will drastically reduce the life of these parts.