I know I do not want acetylene/air, have read too many posts
about its being "dirty".
Not quite. Acetylene and oxygen is potentially dirty, and
usually hotter than you need. But for general silversmithing,
the prestolite or smith air/acetylene torches are among the best
you can use. The way those torches work produces a clean, soft,
gentle and nicly hot flame that’s almost ideal for general
silver fabrication, and hot enough (though only barely) for
casting use too.
Oxyacetylene is sometimes useful, especially in the Micro sized
torches, like the smith “little” torch with the smaller tips,
especially for delicate repair or assembly work on gold. and if
the gasses are mixed right, the flame is nice. But it’s hotter
than you need, in a larger general use torch like the meco
midget, or the like. And if you’ve too much or too little
oxygen, then the flame becomes either dirty and full of excess
carbon, or so hot and oxidizing it’ll burn right through your
metal without melting the solder properly…
I too have natural gas and asked about tapping into that.
Basically it may not be legal into the home, and may invalidate
the insurance.
Depends on local building regulations. In some places it’s
legal, other not. But more to the point, most residential natural
gas lines are at quite low pressure, too low to effectively get
good use out of a torch. Commercial gas lines are pressurized
more, and are often used in jewelry shops. But the ones going
into your home are often at only a few psi. Pretty anaemic…
Check with your local gas company. You’ll generally need above
about 7-8 psi for a torch to work decently.
What you CAN do, if you like this fuel, is to buy bottled
natural gas. Comes in a cylendar same as acetylene or oxygen.
You can use an aceytlene regulator with an adaptor to fit the
different bottle. natural gas is probably the best torch flame
anyway, and is safer to have in the house than propane, since
it’s faster dissipation rate means it isn’t so prone to pool at
floor level building up in concentration if there is a leak.
do remember, if you’re using natural gas or propane, that the
danger of fumes building up is most commonly due to human error.
If you are careful to shut off the gas valve or tank valve when
you are not using the torch, then there is usually very little
chance of a dangerous leak. The fires and accidents you read
about are usually do to pilot lights blowing out (and then
safeties failing to shut of the supply) or more commonly, of
someone accidentally leaving a burner slightly on, or maybe a
faulty appliance. Had the main valve to that appliance been
turned off when not in use, then there’d have been no leak. We
don’t do that with our stoves, of course, but you can reasonably
be expected to do that with whatever torch setup you use. And
while you are there, and using it, you’ll become aware very
quickly of even a minor leak.
Peter Rowe