On both my meco and little torch, I open the propane tank regulator valve completely, start the O2 generator and wait for the O2 indicator light to light, slightly open the propane valve on my torch, light the torch, let the flame stabilize and then slowly open the O2 valve. I then adjust both valves until I get the flame that I want. I have been challenge by an earlier post or two that talked about using an acetylene regulator on propane. After looking at a lot of website information, talking to our local Haun Welding personnel and talking to customer service people at several welding equipment supply places, it appears that, with adapters or modifications to the regulator, you can use an acetylene regulator on propane as long as your working pressure doesn’t exceed 15 PSI. The caveat is always to make sure you use T type hoses, not the R type hoses for acetylene. I would appreciate others who know more about this topic than I to chime in. Thanks…Rob
Hi Sharon, I’m replying solely to commensurate with your situation as these experienced people have already contributed so much. Just wanted to let you know you are not alone - I was in the same exact situation a couple of years ago and could have written the identical letter. Just for an FYI, I replaced my acetylene tank, regulator and Smith carrier for 5lb propane tank, proper regulator and new carrier as I travel to workshops twice a year. (It was my understanding that disposables would not support rosebud-style tips. If that is wrong, I’m sure someone will correct me.) I added a Smith rosebud tip and a set of Paige tips and have never looked back. I’m very happy with the cleanliness, versatility and overall comfort level I feel with this - I don’t regret it one bit! Wishing you the best! Marta
I have and use a Smith’s little torch with disposable cans of “plumbers” mixed gas for fuel and an oxycon I have never had any problems using it with the #4,5,6 and 7 nozzles. I also regularly use the melting tip with no problems. The fuel gas is a bit like Map gas ie prop, butane and a couple of others these aerosol type cans which many crafts just screw a burner on the top of them. They last a reasonably long time and cost in the UK about $3 per can. Insurence companies are happy with them in the home environment. On another blog many have found the same as me
@rmeixner Thx, Rob, detailed instructions are always appreciated 
. Regarding the tubing, without meaning to contradict…It was earlier noted that T grade hose OD is too large to fit on the Smith Little Torch. Also, there are LT kits sold for “all” fuels as well as one for propane/oxy and these “appear” to include the same kind of small fabric covered tubing as those on my kit, which I assume is R rated. Bottom line question is should I worry over much about using my existing hoses as long as I keep an eye on them for leaks?
I have the parts needed to convert, but am still experimenting with the acetylene to see if I can master it. So far the soot issue isn’t too bad, but I still don’t have a clear idea on what the flame should “look and sound” like. See my ? below…
A few easier unrelated questions:
Is the “look” of a neutral flame the same for propane as when using acetylene? I think a “neutral” flame is what I want for soldering, annealing, etc. AND should the flame be noisy?
I open the oxy bottle all the way and open the acetylene 1/4 turn. The pressure on the tank gauge is around 10-11 psi for both. This looks to be what I had them set at in the past, but I don’t have absolute numbers recalled in my memory. Is this OK?
Regarding the use of an oxygen concentrator: What would be a good price for a used oxygen concentrator? I’ve seen them on Craigslist starting around $350 (at least at this moment)…
Sharon
@eclecticvizions Thank you, Marta. I am always happy to hear from others who have had similar questions/experiences . Helps when feeling I don’t know enough to attempt the challenge.
@robinkey I cannot find any fuels other than MAPP, butane, propane in the disposable cylinders. Maybe that mix you can get is not available in the US.
Thx.
Sharon
I don’t think that the T designation has anything to do with size. I bought a very nice T grade hose from the Tin Man that perfectly fits my Meco Torch. Fit is a matter of the size fittings on the end of the hose. They can be A or B size. Check with you local welding supply store. They should be able to help. I took and old heavy T grade hose set in and they cut it in half and added B connections on both ends of one half and an A and B combination on the other half. I can’t help with pressure readings, I go by look and sound. As I recall, when I used regulators with gauges that they were both in the 3 - 5 PSI range. My last concentrator cost about $250 - $300 with a 1 year warranty. God luck…Rob
The gas available in europe is made by a company called Rothenberger and the types are 200, 400 and mapp. and is usually available at suppliers who sell to plumbers and mechanics and some camping suppliers. There are also propane butane mixes that come in the same size cans. It’s quite a good heat but not as good as the three above. I believe that the mapp gas has been re mixed as the old mix was possibly a bit hazardous but the new one is totally different but just as hot. Good luck finding one.
I googled what is a T hose and I got this.
Series 7141/7142 is a premium single line welding hose featuring a flame resistant and oil resistant tube and cover. Red Series 7141 is only for fuel service and is compatible with commonly used fuel gases, including acetylene, hydrogen, natural gas, propane and propylene.
APPLICATIONS: Series 7141 (red): Acetylene, …
COMPARE TO: Thermoid Single Line Corruga…
COVER: Series 7141: Red chloroprene; ribbed …
TEMPERATURE RANGE: -40°F to 200°F (-40°C …
[
Parker Industrial Hose - Welding - Grade T Single Line 71341 …
](Parker Industrial Hose - Welding - Grade T Single Line 71341/7142)
It appears to apply to how the hose is constructed and what materials are used. I found nothing in further searches regarding sizes. That isn’t to say if you looked further you might find something.
Don
@rmeixner Thanks for the info Rob. The Smith Little Torch hoses are connected directly to the handle, no fittings. If the OD is too large, it cannot be attached to the handle. The OD of the LT hose is about 1/4" (maybe 5/16"); ID is 1/8". See pic below. The other end attaches to the regulator with a B fitting. The replacement hose available at RioGrande indicates it can be used with all fuels; that’s not to say that my hose is “all fuel,” but I based on what I’ve read I think still fine to use with propane.
The smallest ID in T grade I can find is 3/16" with an OD of .438, which is too big to fit the SLT.
Thanks!
I guess that I have kind of lost track of the question. As far as I know T is a designation for a type of hose needed for propane. They can have various types and sizes of connections. The Little torch is a system that includes the hose and torch body. It hasn’t changed much in years. Mine is probably 40 years old and looks just like one you would buy today that is made for both acetylene and propane. Thanks…Rob