Thanks Nathan, what about the flashback arresters, do I need new ones when I change the fuel gas?

Jake

Yep- be safe get new ones.

I imagine that most people don't like the rental and refill costs of AC ....personally I bite the bullet because the oxy-acet flame is so much better for stainless colouring

Pepsi

PS check out the recent images under loaves and fishes to see what I mean

Okay, here's a few facts for your consideration:

1. For propane, you need type T hose. Type R, standard for acetylene, will decompose with propane, and little bits of it will clog up the tip and it may fail catastrophically at some point down the road.

2. For operating a rosebud, you may draw more fuel than an acetylene cylinder should be supplying, resulting in a highly unsafe situation. You should never drawm more than 1/7 of the volume of an acetylene cylinder per hour, or you risk drawing some of the acetone from the cylinder. Acetyloene is dissolved in acetone in a pumice filler inside the cylinder,since it cannot be safely compressed in the free state. If you draw off too much of the acetone, the cylinder can become unsafe. Also, drawing off the acetone will ruin you rregulator diaphragm and seals and your torch O-rings.

3. Propane can be safely drawn down aqt any rate the tank will supply without freezing up. For big rosebuds, you need to manifold several acetylene cylinders to be safe, but you can just run one big propane cylinder wide open.

4. Propane is cheaper, most places, than acetylene.

5. You pretty much can't weld with propane. It barely works, if you get lucky, but it doesn' tmake a good weld or a pretty one. It is fine for heating and cutting, though.

6. When using oxy/propane for cutting, you will use more oxygen than you would with acetylene. This is due to the difference in stoichiometric ratio mixtures between the two gases. Still, even with the increased oxygen use, oxy/propane cutting is cheaper than oxy/acetylene. Some people find it easier to cut with propane than acetylene.

7. YOu may need different seals and O-rings in the fuel regulator if you change it from acetylene to propane. Same issue as for the hose. Propane regulators are reasonably cheap, so why not just get the proper one? Save the acetylene regulator for when you need to gas weld.

8. The national fire code allows acetylene cylinders indoors, but not propane cylinders. This is because propane is heavier than air and can fill a room if there is a leak, creating an explosion hazard. Acetylene, on the other hand, is lighter than air. It is also about a hundred times as explosive as propane and far easier to ignite. Go figure.

Hope this sheds some light on the subject.

Thanks Rich, this helps a lot. I talked to my welding supply store and he told me I didn't need to change much of anything. Kind of scary, Huh? I'm glad I've got you all to help me not kill myself with bad info.

Jake

I just hooked up with a "Little Torch" oxy-propane kit and I have been researching everything I can get my hands on about it. These are 2 small tanks. OXY = 20cu ft. Propane #5. I am a very over kill safety minded person.... I even plan to use a separate air supply, as well as, propane/C02 monitors as well, for extra safety. I plan to get in to jewelry fabrication - so I just need to heat mostly and solder sometimes...

The flashbacks can't go on the torch side so I have them going on the Smith regulators (Twin Gauge) side, I had to get a rosebud tip that is setup for propane as well. Smith said that should be fine, however; I have seen some folks say that is is better the FB are the torch side.... May I ask your thoughts?

I maybe at some point be using these tanks/setup everyday... Should I store these tanks semi-outside/outside (without regulators on them) each time I am done using them where the temp might go down to 0F or lower? Right now I have the Oxy tank on my enclosed front porch and I plan to move the propane tank on my back porch which is not enclosed. I have read that the pressure in the propane tank varies with temp. I have seen several suggestions to separate the tanks 30 meters with no regulators on them... I would just like to keep them both side by side in my studio valves off - gas bled and regulators backed off. Any suggestions?

Thanks so much for your help.... I know I can be a bit much at times.

Greg
Princeton, NJ

Hi Rick, I'm changing bc I want to start using a rosebud for heating/bending/forging applications and don't want to invest in the larger acetelyne tanks that I'd need. I don't do much O/A welding and I plan on investing in larger propane tanks for the forge so it seems like a good move. I'll keep the O/A stuff just in case. The cost issue is not as big a deal for me, I'm looking more for convenience. If you have any suggestions, for or against, I'd love to hear them.

Jake

Mele,

You can adapt a regular O/A torch to run on propane by chinging the tip to one designed for propane. Generally, propane cutting tips are a two-piece affair with an extra oxygen jet built in, and propane rosebuds look like O/A rosebuds but have different internals, I think. The torch body is the same, unless you're getting a really huge industrial cutting torch.

You can find complete oxy/propane torch setups at larger welding supply houses or online. I use either Weldingdepot.com or weldingsuppliesfromioc.com for most of my stuff. Both places are very helpful if you call them with questions and their prices are hard to beat.

Thanks a bunch Rich !
Mele

In my glass work I cannot use Acetylene because it is known as a "dirty fuel". It would ruin my colors and conrtaminate the clear glass. Acetylene burns a lot hotter and is best used for cutting and welding steel. I use MAPP gas for heat treating and annealing.

Nic East, Jim Thorpe, PA USA
Creativity begins with a novel thought.

I managed a steel fabrication shop and we found the most efficient heating set up was purified propane (200 deg hotter than regular propane) with liquid oxygen run through a vaporizer for the O2. The largest torch was producing over 1.5 million BTUs. Any requirement for more heat we set up a second torch. Extreme care needs to be used as the actual flame was 60" and it was easy to cook the second torchman. Full service gas suppliers should be able to help you with your needs to correctly balance vaporizers and rosebud size.

Good point, though LOX will continually boil off from the tank, even if it is not being used, so that makes it good for shops where you use a lot of it, but not so good in a shop where there is only intermittent use. Of course, it simply isn't available in some places, such as the Virgin Islands where I live. I can manage without LOX, but I really miss not having access to propylene. That stuff is the balls for cutting and heating.

Rich