Oxy/Propane - The Poor Man's Substitute

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Papa
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Oxy/Propane - The Poor Man's Substitute

Post by Papa » Fri Oct 08, 2010 10:58 pm

This is the business end of my Victor J-28 on a diet of Oxy/Propane

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I've flipped through many of the threads here regarding oxy/acetylene torches, so I thought I'd share my current (rather oddball) setup. I have about 4 decades of 'blue wrench' experience and up until about 8 years ago, I was pretty much a satisfied O/A user. But all that changed when I needed a refill and was astounded at the cost - not to mention that my aging back isn't as capable as it once was at lugging 60+ pounds of bottles around. This had to change,... and change it did.

First take a quick gander at the image below, and you'll see NO oxygen bottle. In its place, is an medical oxygen concentrator (on wheels, no less). A nifty, 50 pound machine that sucks-in ambient air, separates the undesirables, then pumps out 97% pure oxygen at about 9 PSI @ up to 5 LPM. Not quite enough pressure to feed a model 300 Victor cutting attachment, but more than enough to fillet braze a chunk of 1/4" thick mild steel.

My forte is HPVs, or human powered vehicles. I also dabble in metal art. Suffice to say, most of my projects are considered 'light gage', so brazing with LFB along with a variety of Harris silver (mostly 45, 45t and 56) has been my primary tool for most of these projects.

So just how does this system compare with O/A?...

Well, O/P is not without its quirks, that's for sure. It's a little fussy to light, especially in a breeze, and you need to make sure you apply an adequate coating of quality flux to prevent premature charing. It is also extremely challenging to weld with, which I might add, has nothing to do with flame temperature since O/P produces a flame temp in the neighborhood of about 5000°f (O/A is bit higher at around 5700°f). Steel melts, depending on the alloy, around 2500-2750°F. That said, the system accomplishes nearly every task I ask of it. If I absolutely need to weld, I use my MIG.

The concentrator shown below is my second, it was used (about 3500 hrs), didn't function (it needed a $25 HEPA filter), and I paid $25 for it. They are rather expensive new, but on the used market I frequently see them selling for well below $300... or about the same price as a set of full O/A bottles. The propane bottle is an unmolested, 20 pound (5 gal) BBQ bottle. So far, I'm averaging about 15 HPV frames and about a dozen art projects per fill - last refill 8 months ago was $11.60.

I use a victor model 710 (dual stage) acetylene regulator, but most any, externally adjustable acetylene regulator will suffice and even screw-on the LPG bottle if it has the standard CGA 510 fitting (or frequently called a POL fitting). The fuel hose must be "T" rated, as opposed to the more common "R" rated acetylene hose. I use the smaller 3/16". Just cut-off the fitting on one end of the oxygen hose and slide it on the barbed, tapered fitting on the concentrator. I have since tweaked the concentrator's internal regulator to a more suitable 6 PSI - I typically run my fuel reg between 4-6 PSI.

My torch is a Victor J-28 (my third since my first J-27 in early '70), so I have a sizable stock of J series tips. Speaking of tips, the setup functions noticeably better if you purchase a suitable alt fuel tips. Oddly enough, I'm using a UN-J acetylene mixer with alt fuel tips. Acetylene tips will work in a pinch, but lighting the torch becomes more difficult and adjustments are much more sensitive.

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Produced by a single, 15 second pass on a rusty 1/4" thick sample using a Victor #4 tip.

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Art samples using the same torch with different tip

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steamin10
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Re: Oxy/Propane - The Poor Man's Substitute

Post by steamin10 » Fri Oct 08, 2010 11:09 pm

Ugh! What a WASTE of perfect valve handles! :lol:
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.

randyc
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Location: Eureka, California

Re: Oxy/Propane - The Poor Man's Substitute

Post by randyc » Fri Oct 08, 2010 11:32 pm

That's a cool idea !

You scored a very good deal on that machine; as I recall they cost from $400 to $3,000 new, depending on capacity. (I had to rent one after lung surgery. I considered buying but discarded the idea and bought a cane instead, LOL.)

The use of low-cost propane in conjunction with the concentrator is a fine means of providing focused heat for many lower-temperature HSM applications. Assuming that I could find a concentrator for about $200, the concept would economically satisfy about 75% of my personal heating requirements (other than welding, of course).

A question: since the oxy source isn't regulated, is it difficult to adjust the pressure and mix of the propane bottle and is the resulting flame consistent ?

Thank you for sharing your idea, it's a unique one !
Randy C

edited to add: sorry, I missed the part about the internal regulator - didn't know they had one.

farmall
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Joined: Fri Nov 19, 2010 6:11 pm

Re: Oxy/Propane - The Poor Man's Substitute

Post by farmall » Fri Nov 19, 2010 7:57 pm

Thanks for demonstrating that combination works with the J28 and for the detailed info.

I've wondered what a concentrator could support. The bend test sample speaks volumes.

If you can find an oxygen concentrator with the pump option that recharges medical oxygen cylinders, you can use an (use this search term) "Oxygen Cylinder Refill Yoke Adapter~CGA 540 to CGA 870" to connect the cylinders to a conventional welding oxygen regulator.

I fill my medical cylinders with a conventional transfill whip from larger oxygen cylinders since I don't have a concentrator. (I like the light weight for junkyard runs where I only need to make a few cuts.)

5-pound propane jugs are much more expensive than BBQ cylinders, but have the same fitting size and take less space.

Look here for any adapters, pigtails and fittings of interest, then Google the part number for best price:

http://www.westernenterprises.com/enter ... tents.html
Speaking of tips, the setup functions noticeably better if you purchase a suitable alt fuel tips.
Which part numbers do you prefer?

Papa
Posts: 28
Joined: Wed Oct 06, 2010 2:09 pm
Location: Epicenter of Spuds'n Cowpies

Re: Oxy/Propane - The Poor Man's Substitute

Post by Papa » Fri Nov 19, 2010 10:53 pm

Farmall,

With the Victor Models J-27, J-28 and 100J, you'll need the UN-J mixer (Victor P/N 0325-0101), which is threaded to accept the TEN series alt fuel tip ends, are located here:

http://weldingsupply.securesites.com/cg ... 01||1|751|

Alt fuel tip ends are located here (scroll down about 1/2 the page):

https://weldingsupply.securesites.com/c ... terms::PG4

Type "TEN' tip ends (for N/G and Propane) Thread size 5/16”-27 tpi

Victor P/N 0311-0485 Size 2-TEN #2
Victor P/N 0311-0486 Size 3-TEN #3
Victor P/N 0311-0487 Size 4-TEN #4
Victor P/N 0311-0488 Size 5-TEN #5

Tip end data sheet (Note: type 'TE' tip ends are for acetylene only, but can be used in a pinch):

https://weldingsupply.securesites.com/Victortipends.pdf

farmall
Posts: 17
Joined: Fri Nov 19, 2010 6:11 pm

Re: Oxy/Propane - The Poor Man's Substitute

Post by farmall » Sat Nov 27, 2010 1:26 pm

Thanks for the info. Postings like that get useful info out where searchers can more easily find it.

Your thoughtfully mentioning the TPI can help folks with much-loved old torches who want to convert a tip to use the Victor ends.

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