Warning those hoses are only rated for acetylene not propane. If
you use them with propane they will fail from a chemical reaction
with the propane. Which is too bad as I sure would like to have a
set.
Will the black light weight hoses be OK when used with natural
gas?
NO. They are for acetylene ONLY. Natural gas, Propane, Mapp, LPG,
etc, are all pretty similar in their reactivity to the wrong type of
hose. Don’t ask me the exact chemistry involved, but acetylene is the
only fuel gas that these hoses are rated for. The problems with these
can be deceptive, since they will appear to work. The degredation
occurs over time, leading to cracking or weakness/brittleness in the
hose, and resulting slow leaks. Easy to overlook, which can lead to
nasty accidents.
If you don’t want the usual heavier hoses, many commercial jewelers
benches, especially using the Hoke style torch, employ clear plastic
hose. Somewhat similar to fishtank air line tubing, but
thicker/heavier. Polypropelene, if I remember, though I might be wrong
on that. The Little Torch is often supplied with this type of hose,
though in a small diameter with some fancy color added, and sometimes
a cloth sheath over it. Nicely flexible, and lighter than the
standard rubber hoses. This stuff just jams over the tapered nipple
fittings, rather than fitting on screw on tank connections. A hose
clamp, or some heavy wire twisted around the connection to do the same
thing, is sometimes required in addition, on the connections. No good
for any sort of high pressure connection, but the bit of hose leading
to your torch should not be high pressure. The usual method of using
this is to run standard hose to the bench, connecting to a nipple
fitting attached to the bench, so only the short “working” length of
the hose is this clear plastic stuff. One reason is simply that this
stuff is possibly not totally safe for permanent use either. Hot
metal will melt holes in it, for example, and eventually it does also
degrade. But unlike the black stuff, you can see the condition of
this clear hose. As it ages, it will get yellowish, and you’ll see the
plastic developing cracks, so then you’ll know when it’s time to
spend another two dollars on another couple feet of the stuff. I’m
not at all sure if the aging/discoloration I’ve seen in this is
actually due to the fuel gas used, or just age and light, since the
apparently similar types of hose used in the Little Torch don’t seem
to have the problem. That leads me to suspect it’s just damage from
light/UV, or something, which perhaps is avoided by the color added
to the Little Torch hose. Don’t know. No doubt this type of hose is
not formally rated for this use, but as I said, it’s use seems
common in the industry, and if used intellegently, seems to work just
fine with either natural gas or propane.
HTH.
Peter