Natural Gas:
If your gas water heater is using Natural gas then a plumber can
make the installation for you. You must provide an on/off valve
so you can turn off the gas to your torch when not in use. The
line from the on/off valve should be galvanized pipe if a long
distance and about 6-7" of good welders hose at the end for your
torch. Your gas meter has a large regulator already so the gas
coming into your house is already the correct pressure (9 water
columns) and cannot and should not be changed. As always you
should make sure your torch is off when finished soldering and
when you are finished working you should close the on/off valve.
Gas pressure is suitable for both soldering and casting. Oxygen
pressure will depend on your torch, 2-4 psi for small torch
(mini) and 5-7 for Meco torch. Casting torch about 25-30 psi
oxygen. Oxygen pressure should be adjusted for the size of torch
tip being used.
Natural Gas (Safe?)
All gases are dangerous and need to be handled with caution!
Natural gas is lighter than air and if it were leaking your nose
would tell you very quickly! Natural gas will rise and
dissipate quickly. Propane is a heavy gas, if it were leaking
it would drop quickly to the floor or a basement and dissipates
slowly. By the time the gas leaked to your nose level, it would
be a dangerous situation indeed. Propane indoors or in a
basement is a real no-no!
Natural gas is the cleanest of all gases except Hydrogen. Both
are idea for precious metal and hydrogen being hotter is ideal
for platinum. Propane is not quite as clean and runs about 100
F hotter than natural gas. Acetylene as mentioned before, is too
hot and too dirty for precious metals. If your casting with
acetylene, guaranteed you will have porosity.
If the house blew up with propane I can understand why, if it
blew up with natural gas then either no one was at home or they
can’t smell! When finished soldering be sure to close the gas
line and oxygen tank and drain the line, a good habit.
Best Regards, Duane
@pebworth