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Welding carts & compressed gases

DHHok said:
I've never tried that combo. Is the heat similar? I rarely use my gas anymore, except for heating metal to bend it.
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It’s slightly less heat, and there are no brazing tips for that combo

Last I checked it was +$90 to fill an acetylene tank, propane was ~$20-25 and more volume
 
DHHok said:
I waited for the KMS once/yr tank sale. I didn't want to have to fill my tanks very often so I went with the 250cuft for $400 + $120 for the fill.
Your $110 refill for 80cf sounds high, considering I filled a 250 for $120.
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I might have the $110 incorrect. But 59$/50CF works out to =1.18 $CF. So 1.18 * 80CF = 94$ ... not to far off 110$. Maybe was tax in, I cant recall.
But yes, your KMS price sounds better though: 120$/250CF=0.48 $/CF, less than half
 
Chicken lights said:
Oxy / propane is way cheaper to run, if you don’t do any brazing. Plus propane you can get anywhere even on weekends
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I thought people did brazing & silver soldering (meaning silver brazing) quite often with propane/oxygen. Did you mean if they don't do any welding maybe?
Well, maybe I'm looking at smaller scale stuff, models & bike frame tubing stuff. I don't have a torch set, I'm to busy wringing my hands with analysis paralysis LOL
 
PeterT said:
I thought people did brazing & silver soldering (meaning silver brazing) quite often with propane/oxygen. Did you mean if they don't do any welding maybe?
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As far as I know, there isn’t a brazing tip for oxy/propane. I looked into it a couple years ago, I was heating an 8 mm bolt in a tight spot with a cutting torch head, way overkill and not very delicate. I was told they can’t get me a oxy/propane brazing tip

Whats the difference between brazing and welding, referring to oxy/pro or oxy/acet rigs?
 
Last time I filled my acetylene tank, the gas supplier recommended I switch to propane "to save money". I asked if it worked well, and he says oxy/propane is all they use in their own shops. It is cheaper, and, using propane from a barbecue tank, it is very convenient to re-fill. I did a bit of research and determined oxygen/propane would do everything oxygen/acetylene would do except weld, which is fine by me, I don't oxy/acetylene weld anyways. However, I have not pulled the trigger on it yet. This link gives a bit of info on some of the ins and outs of oxygen/acetylene vs oxy/propane.

www.wilhelmsen.com

Gas Welding – Acetylene vs Propane - Wilhelmsen

Ever so often, the question of whether one can use Propane instead of Acetylene will pop up. Learn the difference between the two, and how to prevent accidents.
www.wilhelmsen.com www.wilhelmsen.com
 
You can braze with oxy-propane, you just "can't" weld. I say can't, because you certainly can melt the materials together but there will be a ton of contamination of the weld and it will probably be pretty brittle.

I won an ESAB Victor oxy-propane setup around a year ago, it's still sitting on the shelf and I haven't used it yet, but I do have propane and oxygen, so I should get around to taking it out and seeing what it can actually do.
 
some info (oops same link that @boilerhouse just posted)
www.wilhelmsen.com

Gas Welding – Acetylene vs Propane - Wilhelmsen

Ever so often, the question of whether one can use Propane instead of Acetylene will pop up. Learn the difference between the two, and how to prevent accidents.
www.wilhelmsen.com www.wilhelmsen.com

There are quite a few links about propane/oxygen brazing. Not just weekend warriors but also commercial. Like most things probably application & cost specific.

Oxy-Propane Brazing Update 3 – Novice Frame Builder

noviceframebuilder.co.uk noviceframebuilder.co.uk
 
Chicken lights said:
As far as I know, there isn’t a brazing tip for oxy/propane. I looked into it a couple years ago, I was heating an 8 mm bolt in a tight spot with a cutting torch head, way overkill and not very delicate. I was told they can’t get me a oxy/propane brazing tip

Whats the difference between brazing and welding, referring to oxy/pro or oxy/acet rigs?
Click to expand...
In brazing the bond takes place at over 840 degrees F, with a different filler metal, and the base metal isn't melted (think soldering). In O/A there is more heat available so you can melt steel—specifically the (usually) thicker base you are trying to blend the attachment into. Thus, the base metal melts and, with the addition of rod, blends into the finished seam, becoming one and the same.

With brazing however the melted metal stays largely on the surface. There is a special kind of bonding that occurs at the microscopic level that is different than soldering though. That's why it is higher strength than soldering. I used to braze 4130 chromoly with bronze/brass all the time for recumbent bike frames I made for a buddy that assembled them. Below 840 degrees F it's called soldering.
 
And just a P.S. about bronze brazing. It's a really cool artistic process if you are into that stuff. Because of how it bonds to steel you can do things like create divots in thick steel table legs, braze some bronze into them, sand them down, and you get a beautiful inlay that looks like flush rivets. Bronze buffs wonderfully and looks spectacular. I worked for a long time trying to perfect a process of CNC cutting designs into 16 gauge steel, then bronze brazing the gaps. Sadly, the warping proved too damaging. I could make it work with 3/16" plate, but no one wants a 200 lbs. piece of art hanging above their head behind a sofa.

A CNC mill can cut some shallow gullies into table legs that can be filled with bronze, and you end up with a nice Art Deco look. And for a really fun time—bronze brazing wire in a MIG is a hoot. One day I'm going to buy a smaller MIG just to leave that stuff ready to go at a moment's notice (I hate swapping out rollers and setups).

Sorry for applying the tiller to the thread. I love this stuff :)
 
I got setup for Oxy/Propane last year (went through OxyPro in Calgary). Basically bought an oxy/accet kit, then bought the propane hose/gauges/tips. Kept the accetlyene gagues/hoses/tips as well in case I ever decide to use that.

Practiced cutting on an old forklift plow that was made of 1" plate. cuts great -- I like it. Uses more oxy than propane -- will be upgrading to larger bottle in the future.

For what I'll use it for (heating/bending/cutting) I am quite content.
 
CalgaryPT said:
In brazing the bond takes place at over 840 degrees F, with a different filler metal, and the base metal isn't melted (think soldering). In O/A there is more heat available so you can melt steel—specifically the (usually) thicker base you are trying to blend the attachment into. Thus, the base metal melts and, with the addition of rod, blends into the finished seam, becoming one and the same.

With brazing however the melted metal stays largely on the surface. There is a special kind of bonding that occurs at the microscopic level that is different than soldering though. That's why it is higher strength than soldering. I used to braze 4130 chromoly with bronze/brass all the time for recumbent bike frames I made for a buddy that assembled them. Below 840 degrees F it's called soldering.
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Actually, there's more BTU's available in propane (especially important for heating operations, plus no worry about withdraw rates as there is with Acetylene), but OA burns hotter. The reason you can't weld is the chemical reaction of OP introduces contaminants into the weld where as OA acts like a shielding gas, nothing to do with temperature or ability to melt steel.
 
What about mapp gas and oxygen? My spouse uses that in her tiny jewelry torch. Will mapp gas with oxygen weld?
 
Janger said:
What about mapp gas and oxygen? My spouse uses that in her tiny jewelry torch. Will mapp gas with oxygen weld?
Click to expand...

Technically yes, but it still has more hydrogen in the molecules than acetylene so it will result in brittle welds. Just not as much as propane or propylene.

Propane - C3H8
Propylene - C3H6
MAPP - is a mix technically of a couple molecules, I think it's a couple forms of C3H4 roughly but don't quote me on that :)
Acetylene - C2H2
 
I use a oxy/prop torch, works great but unless you lease tanks all you can buy are the small oxy tanks. They don't last very long if your cutting steel as opposed to just heating stuff up.
 
Back when I was trying to make propane neet emissions levels in cars and light duty trucks, I got my nose bloody over the poor quality control. The trouble with propane isn't propane itself, it's all the other stuff in there - like butane, propylene, waxes, oils, and regular crud.

The price was attractive to consumers, energy density was reasonable for driving long distances, availability was relatively good nationwide, and the low storage pressures made on board fuel tanks reasonably feasible.

But there was no way on God's green earth that we could make emissions numbers anywhere nearly as good as we could with that liquid garbage we all call gasoline.

We even did liquid fuel injection with in-cylinder vapourization. Man did that stuff go like a bat out of hell! But the injectors plugged up with crud and we couldn't make them last.

The propane gas industry all loved to claim fantastic emissions performance, but an actual bag analysis didn't lie like the propane industry did. Poor quality Propane just couldn't make the numbers.

The government even tried to clean up the fuel. It didn't happen. The main market was heating and recreation. There was no incentive to make clean fuel for transportation.

Although I really don't know the answer for metal working, I'd be willing to bet that the lower adiabatic combustion temperatures of propane VS other alternatives is only half the problem. I'd guess that the crud and other content in propane has to be a big part of any problems using it for any kind of metal work too. Perhaps it's also a consistency issue. Not all sources, suppliers, or refiners are the same so fuel varies significantly across the country. "Your mileage may vary."

Anyway, I have enjoyed reading all of your experiences and thought I'd add what I know to the story too.

My own usage is a lot like @6.5 Fan. I like those little mapp/oxy sets you can get at crappy tire. The hoses and the torch are so small that you can use them for things and in places where you cannot really use Oxy/Acet very easily.

I only use Propane itself in the travel trailer and the barbecue.
 
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