For what it’s worth, Acetylene burns pretty hot and is the gas
of choice for working silver here in the sunny southwest USA.
Now for the relatively low-tech part. I recall reading years ago
about how during WWII, the Swedes powered some of their vehicles
by building a sort of furnace which burned wood in an
oxygen-deprived environment, producing acetylene which was
routed to the carburator. Depending on the relative availability
of wood in the remote areas under discussion, perhaps this could
provide the hot-burning fuel needed at such altitudes?
Hi all; I think John (was it?) Williams’ about air’s
composition at high altitudes being the same as at sea level or
other was essential to our problem. I have one
thing to consider though. Suppose compressed air works well at
sea level, with a given orifice and the appropriate mechanisms
regulating the mixture of fuel and air. Now, apply the same
conditions at high altitude. Would the decrease in air pressure
outside of the system cause problems? Would air rush out under
proportionately greater pressure and overdrive the mixture?
Would venturi systems be appropriate here? What kind of
engineer would no these things? Someone with a knowlege in this
area might be in what department of a university? I’m just a
dumb `ol art student. Also, where might I see one of these
bellows/gasoline torches? Thanks in advance.
It seems to me that it would be possible to rig up an old truck
tire with a peice of hose to the valve stem to be used as a
container to provide pressurized air. This could be set up to
run with a gasoline torch rather easily. A hand pump would
provide a recharge on the air supply. This would supply a larger
volume of air than a blowpipe and be easier for one person to
operate than a bellows.
It blows my mind No.2…The high altitude soldering scenario in
a third world situation deserves a solution consistent with lack
of infra-structure. I have a diagram from an old crafts book
which depicts an ingenious method of pressurizing air by
inverting an open ended tank into a larger tank which is
partially filled with water. The first tank then has weights
placed on top which causes the air inside to be pressurized. The
pressurized air is forced out of the top by a pipe which has a
valve connected to a rubber hose. We first world techies have
lost our creativity…Ron at Mills Gem, Los Osos, CA.
about air and gas in higher altitudes… That is the reason for
your pressure regulators. Once you have those outputting the mix
at the pressure you want, than you are set. I am in the sunny
southwest, as one of the others said, but I use propane and
Oxygen. I have pressure gauges on both tanks, and it works
great. Propane burns cleaner than Acetylene, and thus can reduce
the risks to firescale your metals. I have a melting furnace
for casting. If you have to stick with torch melting, stick with
acetylene for that. I am up high, in Northern Arizona, and I have
never had a problem with my mix, but I do keep a good eye on the
regulators, and bleed the hoses regularly
during WWII, the Swedes powered some of their vehicles by
building a sort of furnace which burned wood in an
oxygen-deprived environment, producing acetylene which was
routed to the carburator.
G’day; is the writer fairly sure about this? During the last
war many vehicles in London towed a small trailer containing a
hot coke (or charcoal) burner which had a limited air supply and
which generated mainly carbon monoxide and some dioxide which was
used to power the car or small truck. A similar system injected
steam over the hot coke and this generated what was called ‘water
gas’ and that contained hydrogen (from a breakdown of the H2O in
the steam) so was much more powerful a propellant. Another
system had an acetylene generator on the trailer. This contained
calcium carbide which produced acetylene when water was dripped
upon it. Yet another system had an inflatable bag in the trailer
which was charged with coal gas from the home mains supply.
None of these were a remarkable success, but were in some cases
deemed to be better than nothing. But I know of no system which
would produce acetylene in usable quantity from burning wood.
None of these ideas would be much use in powering a jewellery
torch in a remote area.
My wife wants to know if it is really ethical for the West to
impose it’s methods on those of traditional craftsmen? Should
they be left alone to do things their way? Would something be
lost from the world if their traditional methods had to change
due to methods imposed from outside their society taking over
their crafts?. She suggests that most of the innovations imposed
upon a more primitive society by the Victorians really didn’t do
them much good in the long run? Are Pacific Islanders any
happier at having to wear clothes and get married “properly”
because the missionaries were disgusted? - They’re Jean’s
comments. Cheers, John & Jean Burgess
That is actually a very good suggestion. I have seen it work for
generating combustible gas too. In India the Peace Corps
installed open bottomed cylinders that floated in pits of water.
To this they added their animal (they have lots of cows by the
way) and human waste. Microbes took over from there and the end
result was a supply of methane gas adequate to power a small
generator.
The folks who keep talking about bottled compressed gas and air
compressors need to reread the original post. They have no
electricity and no petroleum supplies at this remote location
and it is cost prohibitive to try to change those basic issues.
So we should focus on things like bellows, bicycle pumps or the
two tanks with weights that Ron at Mills gems just posted.
Think real low tech.
Jim
@jbin
James Binnion Metal Arts
4701 San Leandro St #18
Oakland, CA 94601
510-533-5108
I have a diagram from an old crafts book which depicts an
ingenious method of pressurizing air by inverting an open ended
tank into a larger tank which is partially filled with water.
Ingenious indeed! This is the kind of thinking that we need for
this project. Elegant in it’s simplicity. Would it be possible
to add a simple pressure sensitive valve at the handpiece to
control flow? Kind of like an airbrush? This would give great
control with out all the huffing and puffing of a blow pipe. Jim
This is just a traditional gasholder. it doesn’t pressurize the
air it just stores it at a pressure just above atmospheric . . No
improvement at high altitudes. The bellows or tire pump into a
tire for storage is probably the best low tech solution. Powering
the bellows or tire type pump is just a matter of ingenuity with
local materials and power source -wind ,water, or animal, etc.
Jesse
The folks who keep talking about bottled compressed gas
and air compressors need to reread the original post. They have
no electricity and no petroleum supplies at this remote
location and it is cost prohibitive to try to change those
basic issues.
James Binnion is on target when he points out that we need to be
thinking low tech. I remember using a simple mouthblowing device
in chemistry class to raise the temperature of an alcohol lamp
flame to heat glass and make bends in glass tubing and
eyedroppers. Because I’d have to take a breath, the air stream
was intermittent - OK for glass, but terrible for soldering. I
wonder if the same kind of “bellows” used for the Scottish
bagpipe couldn’t be adapted to provide a steady stream of air
directed at the flame. Just an “out of the box” thought. Judymw
Judy M. Willingham, Consumer Pollution Prevention Specialist 237
Seaton Hall Kansas State University Manhattan KS 66506
(785)532-5418 FAX (785) 532-6944
The high altitude soldering scenario in a third world situation
deserves a solution consistent with lack of infra-structure.
There is a current Japanese cartoon movie Princess Monokone
that, once you look beyond the storyline, has even more
interesting on medieval Japanese technology. The
later action centers around an industrial iron works that
obtains its ore from alluvial deposits.
The author knew enough to stress in the story that the furnance
must be kept going 24 hours a day. To keep the furnance going
the ironworks cut down the forest around them which was the
conflict with the forest spirits in the storyline.
More interesting, to keep that furnance stoked the womenfolk
operate a bellows as large as a house. The women are lined up
on opposite rows on the upper deck and use their feet to apply
their body weight on a pivoted wood platform that compresses
the bellows. To keep balance they hang onto rope straps as one
would in a bus ride.
Do see that movie. The story may look corny to anyone not
familair with traditional Japanese story characters or plots but
the technical and richly illustrated details of medieval Japan
are remarkably informative.
This leads me to the next bit of traditional Chinese
technology, the double acting hand or foot operated bellows.
This is a square wooden box that forces air out on the forward
as well as the return stroke, a simple enough thing to do
through clapper valves. The example I saw was a documenatry
taken before the Revolution showing a dirt poor peasant working
his backyard forge and stoking it with a homemade bellows. I
also recall the anthropologist describing this as an innovative
technology that allowed the ancient Chinese (and other oriental
civilizations) to maintain a much higher forge temperature than
available to other civilizations and thus produce superior metal
work.
This is one probable solution to metal workers in remote third
world areas.
Hi Jim, A simple needle valve would work. As long as the pressure
upstream of the valve is greater than that downstream, the
downstream pressure would be very close to constant for this
application. NASA may want something more sophisticated, but
their sophisticated stuff craps out too (to the tune of 100’s of
megabucks). Dave
Hi Jim, A simple needle valve would work. As long as the pressure
upstream of the valve is greater than that downstream, the
downstream pressure would be very close to constant for this
application. NASA may want something more sophisticated, but
their sophisticated stuff craps out too (to the tune of 100’s of
megabucks). Dave
I remember using a simple mouthblowing device in chemistry
class to raise the temperature of an alcohol lamp flame to heat
glass and make bends in glass tubing and eyedroppers.
G’day; as I mentioned in an earlier post, I spent some while
producing scientific glass apparatus using double acting, foot
operated leather bellows, using coal gas as fuel. Equipment
included items as sophisticated as water powered vacuum pumps,
distillation condensers, and even Soxhlet fat extractors, but in
ordinary soda glass. Admittedly I used an oxygen boost to the
bellows air for work on Pyrex glass. 52 years ago! So (low
pressure) compressed air in a remote place is no problem; it’s
the fuel gas that is difficult, but petrol (gasolene)-and-air gas
would solve things. But should we really want to change the
Tibetan worker’s traditional methods? 6000 years ago, beautiful.
intricate gold and silver jewellery and artefacts were made using
the common charcoal brazier and furnace, an oil lamp and reed
mouth blowpipe. Should we really try and push the Tibetan
silver/gold/brass smiths into the 21st century? It might amuse
some of you if I tell you of a 16 mm film I had to project to a
chemistry class long ago. The action was set in a remote part of
Africa, and the tribe were making iron from haematite ore and
limestone, using a huge charcoal fired, clay furnace. The
bellows were wood and leather, and double acting, the size of two
cars, and part of the magic ritual was the dance of the women on
the bellows to the music of pipes and drums and a rhythmic
chanted incantation from the ‘iron master’ and chorus of youths
and maidens. It took all day and night. Exhausting and all good
clean fun, no doubt, but it did produce a lump of iron for
further work by the smiths to turn into swords and ploughs.
Apparently the tribe had been doing this under great secrecy for
many hundreds of years! Long, in fact, before the West made
iron and the British were rushing around dressed in woad…
There really ain’t nuthin new! Cheers,
Jesse, The inverted tank routine does work for pressurization of
air and is proportional to the weight of the inverted tank along
with the weights which have been placed thereon. The original
diagram showed two sections of railroad rail serving as weights.
The other variable would be the depth of the water in the
container tank. Obviously if too much weight were placed on top
of the inverted tank the resultant pressure would force the air
out of the inverted tank. As for pressure, it should be
remembered that the pressure required is really not very
great…obviously a mouth blowpipe does not create much
pressure, yet it does work quite well.
While we are on the general subject, it should also be noted
that the original communication from Jatu stated that gasoline
was being used as a source of fuel gas. In the diagram that I
mentioned gasoline was also being used. Therefore, contrary to
many comments made by Orchidians, there was indeed a source of
hydrocarbon fuels. The gasoline could also be supplanted by the
water/calcium carbide method of acetylene generation. After all,
the acetylene that we buy in tanks has been generated by the
same method. The only difference is that when acetylene is
highly pressurized is is extremely explosive, even to container
impact. Were it not for the fact that our tanks contain acetone
and a filler compound we would long ago have been blown to hell
and gone! Ron at Mills Gem, Los Osos,CA
You don’t get more pressure out than you put in!!! It just
stores. The weights just balance the buoyancy. The pressure is
inches of water and is created by the work put into the bellow or
tire pump or whatever. In a gas holder used to capture methane gas
from an anaerobic biological digester gas is produced at the
pressure balancing the bell but it doesn’t increase it.
Acetylene from calcium carbide might be a feasible fuel but the
carbide would have to be hauled in and imported from maybe India
or China. There probably are acetylene generators available from
China. One is easy to build. They are not super safe to operate
but they do work. Jesse
Two thoughts: First, is there any way to solder using paste flux
and a carefully controlled charcoal fire? Second, does anyone
have a diagram of the two stage bellows used by ancient
blacksmiths. Insstead ot just blowing on the down stroke like
modern fireplace bellows the medieval ones blew on both up and
down stroke. These two URLs are some of the meager resources I
found on the net. Geo.
While we are on the general subject, it should also be noted
that the original communication from Jatu stated that gasoline
was being used as a source of fuel gas.
My reference to the petrochemicals was about the suggested use
of them in internal combustion engines to run generators or
compressors not as the basic fuel for the torch. The quantities
required for the torches is small enough to be carried in packs
on man or animal the quantities needed for a generator or
compressor would need to be carried in on a motor vehicle.
The idea of a inverted tank pressurizer is a good one but you
still have the problem of how to refill it. If you have to take
all the weight off and lift the tank up on a regular basis I
think it might be too labor intensive. If you are going to use
hand pumps or foot pumps to fill it then why not just use a tire
or a small pressure tank instead of the more cumbersome water
and air tank arrangement.
Jim
@jbin
James Binnion Metal Arts
4701 San Leandro St #18
Oakland, CA 94601
510-533-5108
How about getting a used car tire on a rim with an inner
tube.Using a hand pump (bicycle pump) it is possible to inflate a
scrapped car tire to around 35 to 40 psi. Using the same type of
fitting that is on the bicycle pump (the type that clam ps onto
the tire filler)you can attach a simple valve regulator with a
rubber hose(use fuel line hose)(also, clamp all hose connections
from the valve back to the tire or the hose will come off…).
Now, take a large glass milk bottle or cocacola bottle(they
still have these all over Asia specially in upcountry areas)get
a cork that fits the selected glass bottle and put 2 pieces of
copper or steel tubing through the cork so that 1 piece goes to
about 1/4 " from the bottom of the bottle…(this is the piece
of tubing that the air hose from the car tire valve will be
connected to.) Then connect the torch ( the torch can be made
with a small piece of copper tubing …or use the existing
simple torches that they have.) to the second piece of metal
tubing that is inserted through the cork so that tube stops
about 3 inches above the Gasoline that you will fill the bottle
with. Now, when you turn the valve (slightly), you are passing
air into the gasoline in the bottle.The air picks up gasoline
fumes in the bottle and exits through the torch handle …if you
light that end… you have a torch. Your flame is adjusted by
turning the air valve. I used a system like this in Thailand in
1968 when i learned how to make hand made jewelry … the
original system used a foot operated bellows for the air
pressure and that worked fine for most applications.The
advantage of the car tire was that the air flow was controlled
through a valve ( instead of the speed that you pumped the
belows) and you could work for about 20 minutes before pumping
the tire up again. The other advantage is that you could build
larger torches with the capability of more heat and larger flame
for soldering items like handmade silver bowls. Hope this is
helpful … Danile Grandi http://www.racecarjewelry.com