Dear All, Natural gas and Oxygen is the best bench fuel you can use.
It has been proven by every Jewelry manufacturer and Repair shop for
the last 100 years. You don't need more than 1/2 pound pressure to do
bench work as well as casting. The success is torch based. The little
torch just needs the larger torch tips to work properly. The finest
tips work the best with acetylene and propane but not natural gas.
The Smith and Hoke torches work well with any fuels.
The control you can get with this combination is the best. The flame
at the bench is not too bright to look at. There is no soot when
lighting. I can guarantee anyone trying this would fall in love with
it. Soldering and fabricating brass, sterling, gold and platinum
works well with no major problems.
I hooked a gas ball valve directly on a "T" black pipe natural gas
fitting by my furnace and put a hose directly to my torch. It worked
like a charm for the five years I had my shop at home. You can do all
the pipe fitting your self with natural gas black pipe available at
most hardware stores.
In my current shop I have propane. Most building codes forbid more
than one or two pounds of bottled propane inside. I just don't use
the large refillable kind. I made hose fitting to run two small
disposable tanks (under two pounds) that go to a camper pressure
regulator and then to my torches. All code and no fire code
I prefer to cast with propane. In most cities the natural gas is
piped in from various sources. I can't say if they are all exactly
alike, but using the torch in the winter time we see various colors
coming from the torch. I contend that city natural gas is great for
furnaces and bench work, but not for casting.