propane and oxy/propane torches question

[Dave English]

I would like some advise about propane and/or oxy-propane torches. Some of the work I want to do should be easyer to heat with a torch. I have a new smaller acetylene torch setup that I have to learn how to use but propane is so much cheaper that I wondered about using a casting torch or other propane or oxy/propane setup. One additional important question, can the setup for acetylene, the gages and valves, be used for propane or would I have to buy another gage for the lower pressure propane?

[Mark Aspery]

I use the same gauges on my set up. I use both types of fuel depending upon the application.
I do have to change tips depending upon the fuel type.
I use Propane for most of my work - utilizing a propane/natural gas specific smith 'gasaver' for quick start/stop work. I really encourage you to get a gasaver... I wouldn't be without one.

[Trollhammer]

I'm not entirely sure on this, but I've been told that using propane with acetylene hoses isn't a good idea, but using the same gauges would be ok. I wasn't given a reason, so hopefully someone can correct me and fill in the blanks on that. I'm pretty curious now myself.
Mickey

[phil shelton]

hose are different now that said my supply house dose not stock propane hoses because no one use the propane hose i was told by them to use my hose. regulators will work.

[rlarkin]

Standard hose is Grade R, for Acetylene only. Grade T is for all fuels.
It is said that Propane will cause grade R to deteriorate. My last grade R hose lasted 30 years using propane only. I now have a grade T.
You must however different tips, and deffinately use flash back arrestors.

[Dave English]

Thanks guys, I've been holding off investing in a specific propane setup until I got some advise from fellow backsmiths, now I can take most of that money and buy iron, and maybe some new tools when I need them. Mark, I'll look into that gas saver and pick it up.
Dave English
Oceanside, California

[tech413]

Where can you buy this gas saver setup?

[SGropp]

I was advised that an acetylene regulator will not safely handle the higher pressures and flow needed for an oxy/propane torch of any size.
Using a oxy / propane rosebud uses dramatically more oxygen than a similarly sized oxy / acetylene tip, somewhat offsetting the savings in fuel. The advantage is that you do not have the high tank withdrawal problems using oxy/ propane that you have from pulling a lot of acetylene out of a tank [ you should not withdraw more than 1/7 of the actual content of an acetylene tank per hour or you risk withdrawing the acetone base and risking a dangerous flaskback ]
For big heating tips I use a propane line supply with a propane regulator and 2- 250 cu ft O2 tanks manifolded together . The hose and tip is designed to be used with propane fuel gas .
The gas saver is very handy and will pay for itself in short order. Get them from a welding supply house. Victor and Smith are both reputable brands.
My advice on any kind of high pressure fuel gas equipment is to buy professional grade ,name brand gear from a reputable dealer. It will give years of safe and reliable service if taken care of and parts will be continue to be available and it will retain it's value if push comes to shove and you have to flog it.
If you can find it, Chemtane 2 [ propane with some kind of additive ] give a hotter flame temp and less oxygen consumption than regular propane. Use equipment rated for propane.

Edited December 30, 2008 by SGropp

[Chuck Richards]

The only thing I was told when setting up my Oxy Propane outfit was you can not weld with it. Not enough carbon in the flame. I have no need to gas weld so not a problem. It is so much cheaper to operate I will make up the difference in set up costs quickly.

[Frosty]

If you want a proper oxy/propane torch you need to buy the Allstates torch. Sure you can use propane "conversion" tips on an acet rig but efficiency is poor.

Magnum System

The Allstates rig is designed from the regulators to the tip to burn propane and costs about 2% as much in consumables as oxy acet. The torch set is expensive, last I checked $650 but mine paid for itself 3x before I had to refill the first 20lb. propane bottle.

Shipping is also a lot easier. Just try getting an acetylene tank on an airliner, go ahead, call and ask. Oxy is no problem but acet? Forget it. However, you can buy propane virtually anywhere.

Then there's performance to consider. Using the same 0 tip on the cutting head I can adjust it to cut 20ga without warping or crank it up and pierce up to 5" without overpressuring.

Propane doesn't inject carbon into the steel so doesn't cause a hard zone you have to grind away before machining. I'm not talking about heat effect on high C steels. You can literally pierce a hole with the torch and as soon as it's cooled enough chase it with a HS drill bit. Torch cut a piece of steel and chuck it in the lathe and go to work with HS tools.

The #5 heater (rosebud) can be covered with the end of my ring finger and will melt 1 cu/in of steel in under 13 seconds. An equivalent oxy acet rosebud will just have red showing across the top of the steel cube in this time.

Brazing is a dream, the rod flows like trained butter and the joins are stronger than acet. Forget gas welding with it though, it doesn't work worth spit regardless of what the guys selling them say. I've never seen a good weld made with one but can be convinced if someone can do it.

Then there's the thing that really kicks the efficiency up the thumb valve. You adjust the torch for the job and use the thumb valve to turn it on and off, not wasting gas leaving it burning or adjusting it every time you turn it on. This rig has the gas saver built into the handle.

Another really cool trick is to attach a trickle charger to the handle and ground it on the table. Then you can flip the thumb valve and touch the tip to the table causing a spark lighting your torch. They sell a scratch start igniter but I have enough Scott in me to not buy one when I can make one for peanuts.

I don't make anything from Allstates and my only affiliation is owning one of their torches for the last 25 years or so. If you talk to Lyle tell him Frosty says hi.

Frosty

[KYBOY]

Ive used Victor, Smith and a host of others..I have a Smith in my shop..Right now on Act, but I have the tips for propane..propane is more cost effective but you cant weld with it and you are advised to use "T" grade hoses..I switch back and forth as needed..

[tech413]

I think maybe I'll sell my oxy/act torches and buy the one's you're talking about Frosty, sounds way better!

[Dave English]

Frosty, good post. The information you wrote sure makes a case for the Magnum System. I can't say right now if I'll get one but you have pointed me in the right direction for savings and efficiency (once the item is bought). For the time being, I'll have to adapt what I have and see how it works.

[Frosty]

I think maybe I'll sell my oxy/act torches and buy the one's you're talking about Frosty, sounds way better!

If you think you'll do ANY gas welding reconsider selling the acet rig.

I have electric welders that do virtually anything I need so I haven't hooked up either of the two acet torch sets I have and gave #3 away maybe 15 years ago.

Frosty

[tech413]

Thanks for the heads-up Frosty, but I have 2 electric welders that I do all my welding with. I think I'll look into the propane set up, thanks for the info.

[Ten Hammers]

Harris used to make a Thumb nut torch. I have used one extensively with LP. This was years ago. Was an OUTSTANDING torch. Had a standard torch body with a valve in the torch, paralell to the torch body that you turned on and off by simply using your thumb. Once the torch valves were set, turn off at the thumbnut. My welding supplier told me I guess 5 years ago that the torch ( Harris ) was not available. Inside 5-6 months he told me that it was available again. I really had a need but that is when I bought the Smith Gas Saver.

I weld extensively with gas ( and Mig ). I use the hand forge ( Henrob and gas saver ). I have QD's on the gas forges and I can hook up either of my weed burners to the bottle. I admit that an Oxy propane rosebud would be nice from time to time but in my case it is so limited that my choice is now and will always be Acetelyne.

The original thread was questions about LP. Your welding supplier can answer these questions. I have had Victor in the past and used Harris and Smith. The newest torch is a Smith set ( regulators and torch/hoses ) that I bought probobly 8-9 years ago. The Henrob was bought used from a friend and with the gas saver, these 2 tools are the smartest investments I have made in a long time.

My needs are perhaps different than yours. I was taught fusion welding with acetelyne in I guess 1968. I have , yes over the years brazed an 8" Wilton vise base ( cracked in two ) and other braze jobs with LP. With the Harris thumbnut torch and with other LP torches. My preference is oxy/acetelyne because I like it and it is predictable for me. I most certainly would not sell the acetelyne setup if I was to consider another blue wrench ( Oxy LP ) for the business. The welding setup is neutral flame and I replace bottles maybe twice a year. All in the cost of doing business. I cut with the plasma unless it is mongo big and then I use the Smith ( and I cannot recall the last time I did that ).

Edited December 31, 2008 by Ten Hammers

[ChrisB]

The local welding shop told me oxy/propane uses 3x the amount of oxy as oxy/ace. So you negate the savings by spending more on oxy.

[Lysdexik]

ChrisB two of the MULES told me that too, but the third didn't agree
Paul

[Frosty]

The guys at the welding supply ALWAYS say that. It's their job to make sure you buy THIER products, from Victor torches to acetylene.

The reason a torch running propane uses 3x oxy is because it's an acetylene torch with a conversion tip. The lowest setting you can get on an acet regulator is above 1psi. Propane isn't even adjustable on the Allstates rig, the reg is sealed and the propane is metered according to the oxy flow. At it's highest flow rate, (that's with the oxy set above 130psi.) propane pressure is around 4-5ozsi (ounces per sq in.) It's simply not possible to adjust an acet torch to burn propane properly. There are a raft of other reasons it doesn't work well but they're involved and can't be corrected with a conversion tip.

Harris builds Allstates torches under contract and makes a version of their own but can NOT use the Allstates proprietary tech, so their torch falls short on performance and economy. Of course it's quite a bit cheaper in the short run but. . .

Frosty

Edited January 1, 2009 by Frosty

[bipolarandy]

This year I bought a Oxweld/purox brand oxy/propane torch set up for cutting and heating and I love it, it uses a normal 0-60psi regulator for the propane that i manifold off my big tank so i can run the forge and the torch at the same time. Chris is right about going thru oxygen, you can empty a tank really fast, but oxygen is cheap compaired to acet, and if your just using the torch , the propane lasts forever.
The unit I got was like 300 bucks, and that had the torch body, rosebud, cuttin head, hose, and regs.

[KYBOY]

You know I like victor torches and have used plenty but the last shop I worked out of seemed to get a bad run...They blew gaskets out of the body almost weekly for some reason..:confused: kept having to send them back for rebuilds..They were covered by warrenty of course but thats a lot of down time when you need one..One popped while I was cutting the teeth of a dozer bucket overhead..I got the top of my head blistered with slag when it scared the crap out of me..After I put my hair out i went and changed my drawers..

Edited January 2, 2009 by KYBOY

[evfreek]

The local welding shop told me oxy/propane uses 3x the amount of oxy as oxy/ace. So you negate the savings by spending more on oxy.

This is an oft-quoted "fact", and it can lead to an erroneous calculation. So, where does the 3X figure come from? If you look in a welding data handbook, like the Uniweld guide that I reference, 1 cu ft of acetylene requires about 1.1 cu ft of oxygen, while 1 cu ft of propane requires about 4 cu ft of oxygen. At first glance, it would seem that the local welding shop is correct, and that the savings is negated. Not so fast!!!!! The book also lists the heat produced: 1470 BTU for acetylene, and 2498 BTU for propane. Thus, if you are using a rosebud for heating, you get more out of a cu ft of gas, which effectively attenuates the 3X factor. In this case, 2498/1470*1.1/4 = .467, meaning that one cu ft of oxygen will give you nearly half the heat with propane as it will for acetylene. In addition, acetylene costs quite a bit more than oxygen. In one report, acetylene cost $67 for a 75 cu ft refill, while oxygen cost $24 for a 125 cu ft refill. So, per BTU, you may be paying slightly over 2X for oxygen, but you save quite a bit more by not buying acetylene. Putting this another way, oxygen cost per 1000 BTU using acetylene is 14.3 cents, versus 30.7 cents for propane. But, the acetylene cost is 60.7 cents, totally swamping the difference, even with propane costs.

Furthermore, if you look up the cutting costs in the Uniweld data book, oxygen consumption for propane and acetylene are listed as the same. Actually, they are not quite the same, since the preheat is slightly more effective with acetylene, but once you press that oxygen lever down, they will be quite similar, since the cutting oxygen flow down that center hole will be the same for the same sized tips. Oxy-propane users will be expected to do a good proportion of cutting, so this will further cut the relative cost of propane.

In addition, there should be less trips to the welding store, less annoying hazmat charges, and less tank rental, since blacksmiths usually have a bbq tank around anyway.

It is really interesting, though, what the origin of this 3X number is. Doing some reading, it seems that this number comes from the fact that much of the acetylene's combustion heat comes from the primary combustion (C to CO). Due to the kinetics of combustion, much of propane's heat comes from secondary combustion, thus requiring more oxygen. If one could catalyze the combustion reaction so that primary combustion were enhanced, the 3X factor would decrease. It appears that this is the reason that the alternative fuel gases can achieve lower oxygen consumptions at similar heats of combustion to propane. Many of these gases are nothing more than propane with a few ounces of additive per 20 lbs., not enough to increase the flame energy, but enough to sufficiently speed the combustion so that less oxygen is needed for the major part of the heating. Interesting, but nobody seems to sell the stuff locally.

[bipolarandy]

Very informative Evfreek,
My gas dealer asked me about swiching to somthing they call high-carb propane, or F-G2, a propriarity blend that supposedly would burn a few hundred degrees hotter than standard propane. Too bad it was almost twice the cost. :O