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Why Acetylene?


#21

Hi Dave,

I just went to the welding shop and got the tanks and regulators
at the same time. Have no problem at all with it.

Bill Raby


#22

Dave,
The fire inspector here in florida,tells me that the large
bar-b-q tanks are extremely dangerous, should they leak.They
contain alot of gas! He recomended I use disposable tanks, they
last pretty long! I do alot of goldsmithing and don’t use a whole
tank in a week.I split the conection and run both my mini torch,
and a hoke for melting. I’m set up with the large oxygen tanks
and small propane tank. I also learned that they can be refilled,
a adaptor is available that attaches to your large tank. If you
should have a leak the small tank still holds alot of gas, but
would easier to air out the space. ALWAYS CHECK YOUR CONECTIONS
WITH SOAPPY WATER!! Best of luck, and be Careful, Greg Alexander

A working goldsmith studio in Bonita Springs, Florida
E-mail Address @oryalex


#23

The seal should come from the male/female connection, and the
threads just provide mechanical force. I switched out both the
adapter and the tank, but no joy. I also took the whole assembly
down to the welding supply shop and they gave up.

I’ve had the same results with a brand new bbq tank.

And you’re quite right, the seal between the regulator & the
tank should be made by the conical shape of the mating pieces.
That’ s why you should ‘crack’ the tank valve briefly before
inserting the regulator. The escaping gas should blow any foreign
material out of the connection. Also check the conical end of the
regulator for nicks. If either the regulator or tank connection
is nicked or has some debris on it you’ll never get a good seal.

FWIW, BBQ tanks have a date stamped in them near the valve. When
the tank gets to be 10 years (I think) old the valve & valve tank
connection must be checked for leaks. The charge to re-certify an
out of date tank is usually more than the cost of replacing the
tank, about $20 around here.

Too bad they aren’t as stringent about making new tanks have
fittings that don’t leak.

Dave


#24

GF> my fuel supplier showed me a picture of a
GF> welder cutting one (or was that two?) inch steel plate with
GF> propane/oxy set up.

G’day George et al; once more, nothing to do with jewellery, but
as you raised the subject, George, I was quite unable to keep my
nose out of it!
Referring to gas-cutting steel, Perhaps one should take into
account the fact that a special torch is used by professionals,
and it doesn’t matter much what fuel is used. You see, a good
strong oxygen/fuel-gas flame is used to heat up the steel to
orange hot then a trigger on the torch is pressed which enables a
very powerful stream of pure oxygen to strike the hot metal - and
it is that stream which really does the ‘cutting’ - or more
literally, burning. The oxygen combines with the iron at red
heat to produce iron oxides, and that reaction generates more
than enough extra heat to melt the iron, so the molten iron
together with the oxides is blown out of the hot-spot. Thus if
the torch is kept moving, a shape is easily cut. But if you want
to prove this, use your jeweller’s torch with oxygen and propane
to heat a spot on a bit of fairly thin scrap iron (16 SWG, up to
1/8th") until the spot glows orange, then quickly open the oxygen
valve - and begin cutting!
WARNING: wear a pair of protective gloves, some old clothes(!!)
and very dark glasses. Oh yes, and for this trick you should
have anti-blowback valves fitted on your cylinders. And yes, of
course I have done it myself!

        /\
       / /    John Burgess, 
      / /
     / //\    @John_Burgess2
    / / \ \
   / (___) \
  (_________)

#25

Hi Dave,

It’s a bbq (20? lb tank). I inspect the threads on the exchange
tank very carefully, and clean both my regulator threads and the
tanks threads meticulously. I also take the tank and bbq
several times before I bring it inside. A tank 9/10’s full is
safer inside.

Regards,

Skip

                                  Skip Meister
                                NRA Endowment and
                                   Instructor
                                @Skip_Meister
                                06/07/9700:05:06

#26

The fire inspector here in florida,tells me that the large
bar-b-q tanks are extremely dangerous, should they leak >>

In Wisconsin you are only allowed to have one 4.5 lb. propane
tank per room. The Bar-B-Q type are much bigger like 20 lb…
These little ones last a long time, I have three torches going
all day on each tank, and they last about a week and a half. The
disposible ones are much smaller (too small I think).

Mark P.


#27
 Looks like I should have asked this question years ago, but
 never thought of it. I keep the oxygen on my little torch at 5
 psi and on 4 psi on the propane.  Has always worked well, but now
 I am wondering if this is correct? As a matter of fact, I just
 looked, and my regulator for the oxy only goes up to 30 psi.  Any
 other opinions?  When I start using platinum will I have to
 increase the oxygen pressure?

I learned to use a torch welding steel and was taught to use
even pressures. For most things that seems to work fine for me. I
generally use 5 psi & 5 psi, although I had a fellow working for
me who seemed to like about 10 psi on the oxygen. I could still
adjust the torch to get a soft flame, but I had to be careful
when I used a small oxidizing flame, the flame could be a bit
hotter than I judged it to be. Whoops.

Platinum won’t oxidize so you’re free to use more oxygen to get
the temperature up there.

As long as I’m on the subject, I started out with acetylene and
switched to propane. I didn’t have to change regulators or use an
adapter. I was using a small acetylene tank (3 1/2’ tall approx.)
and switched to a 20lb propane tank. For what I’m doing nowadays
I prefer propane.

Dick Caverly
rcaverly@aol.com


#28

Have been watching the thread re acetylene vs other types of
gases and couldn’t help putting in my two cents. When I learned
silver/gold smithing in Taiwan about 25 years ago we used
"gasoline generators"

Like to add something that I saw first hand in Iri
City,Korea.This is the Gemstone cutting center for all South
Korea.(not by choice,the Government rounded them up from all over
the country to a barbed wire compound to stop the smuggling)

Anyway,the process of cutting Gemstones requires the workpiece
to be affixed to a metal stick to be later chucked into the
machines.This process is called “dopping” The adheasive can be
super glue,shellac,or any number of waxes.These "dopping waxes"
are in the most common usage.To apply the wax it must be
heated.This is done in what’s called(of course)a dopping pot,a
kind of hot plate with an inverted cup to hold the melted wax and
a platform to heat the stones.This process can take a few minutes
for the stones to heat up and wax melt.But as I toured the
factories in Iri,which are completly filled with child labor
bussed in by the government,I saw to my horror they used gas
flame for the dopping process.When I tried to explain to the
factory owner the methods used in the west,and that these
unstrapped gas tanks in the hands of children was dangerous,he
shrugged and told me he knew all about the alternatives.But they
were too slow.And told me that his factory alone had 2-3 deaths
per year as a result of explosions.Simply the cost of doing
business.

                                        Mark Liccini
     LICCINI

Gemstone Rough Dealers since 1970 U.S.MAIL
E-Mail: @Mark_Liccini1 107 C.Columbus Dr.#1A
http://www.LICCINI.com Jersey City,N.J.07302
Voice Mail/Fax: 201-333-6332


#29

I would like to try out Hydrogen.

hi stephen and all,

you write that you were using acetylene and you were
experiencing the o rings melting etc.? and this was at the
revere acadamy? off and on i’ve attended workshops there for the
past 6 years and have never seen an acetylene tank. as far as i
know they use natural gas for soldering(not my favorite) and
propane for platinum fabrication and casting.

first, as far as i know and as my fuel supplier informs me the
regulators and tips are interchangeabe for propane and
acetylene. they suggest T rated hose for propane though. what is
not interchangeabe is the mixer tubes lacated between the tip
and the torch handle. all the tips for a smith little torch are
interchangeable except of course 1, 2, 3 tips which don’t work
for propane. smith also have a nifty rosebud tip that is not
interchangeable. the propane mixing tube is significantly
longer.

i believe the problems you and your friend are having is due
perhaps to an incorrect mixing tube. as i’ve said before, i
experience no problem melting a charge of platinum of 1 oz. i
haven’t had the need to melt anything larger but i have no doubt
that i would easily melt a capacity 3 oz. charge in a wesco
fused silica crucible with my current popane/oxy set-up. i use a
regular medium duty welding torch kit made by harris. i’ve
installed a propane mixing tube and use a D-50-C rosebud. though
a single hole tip would propably work as well. to melt the
platinum charge i set my regulators to 45 for oxy and 5 for the
propane. this morning i melted a 35 gram charge in less than a
minute. no preheating of the crucible. the valves on my torch
handle were not fully open so the hose pressure probably could
be turned down some. the bright inner cone was held appro 2
inches from the metal, concentrated the flame on the metal and
moved the tip back and forth semi fast.

it was not clear to me when you talked about the revere class.
were howard and chris experiencing diffuculty? ed friedman
usually teaches the platinum casting there and he very
successfully demonstrates casting platinum using propane. he
also demonstrates using the neycraft spincaster as well as the
more traditional vertical set-up. i’ve not taken the class but
have observed it and the great results obtained using these
methods.

anyway, if your friend would make the aforementioned changes to
his oxy- propane set-up, he’ll probably eliminate his trouble
melting platinum. i confess i don’t know a thing about scuba oxy
tanks, thats why i say probably.

best regards,
geo fox


#30
you write that you were using acetylene and you were
experiencing the o rings melting etc.? and this was at the
revere acadamy? off and on i've attended workshops there for the
past 6 years and have never seen an acetylene tank. as far as i
know they use natural gas for soldering(not my favorite) and
propane for platinum fabrication and casting.

This was NOT at Revere Academy, It was where I work. I was told
it worked very well at Revere.

A SCUBA tank holds compressed AIR, not oxygen, so that is why it
doesn’t get hot enough! I will suggest he try oxygen next time.

I did not attend the class. Howard came up to my shop to
demonstrate the technique, and to sell me some platinum, as he
was a sales rep for a metal supplier. We tried casting with
oxy/acet. but with the bad results I spoke of.

George, I think you may be winning me over to propane!

Thanks for the specifics, and please know that all of the
classes I have taken at Revere have been quite good, I am not
saying that it was any fault of theirs.

Stephen Bargsten


#31

What was that tip onusing T. Paper as a heat sink… been down
for a month… trying to catch up

Thanks,

Jim Bennett


#32

What was that tip onusing T. Paper as a heat sink… been down
for a month… trying to catch up

hi jim,

by the time i read your post, everyone else had already answered
your question. just wet the appropiate amount of toilet paper,
cover your heat sensitive area, and start soldering. as long as
it’s hissing one should be ok(that means there’s still water in
the paper and the gem is not much hotter than boiling). try to
position the toilet paper so if there is steam it won’t rise and
blow out ones torch. this works great on gold and platinum and
is somewhat effective on silver. silver is a great heat
conductor so it poses some problem.


#33

first, as far as i know and as my fuel supplier informs me the
regulators and tips are interchangeabe for propane and
acetylene.

Hi George,

Be careful, anyway. Safety regulations here in Germany tell us
that acetylene can disintegrate at higher pressure explosively.
Regulators are not to be opened to more than 1.5 kg/cm2 (1.5
atmosphere,which is about 21 psi, if my conversion program is
right). Furthermore, it is not allowed to use fittings, tubes
etc. made of alloys with more than 65% copper, as the acetylene
reacts with copper forming copperacetylide which is explosive.
Don’t blow yourself up, Markus


#34

first, as far as i know and as my fuel supplier informs me the
regulators and tips are interchangeabe for propane and
acetylene.

Hi George,

Be careful, anyway. Safety regulations here in Germany tell us
that acetylene can disintegrate at higher pressure explosively.
Regulators are not to be opened to more than 1.5 kg/cm2 (1.5
atmosphere,which is about 21 psi, if my conversion program is
right). Furthermore, it is not allowed to use fittings, tubes
etc. made of alloys with more than 65% copper, as the acetylene
reacts with copper forming copperacetylide which is explosive.
Don’t blow yourself up, Markus


#35

Bill,

We use the small Little Torch with O2 and propane all the time.
Small tips work just great. For those who do not know, the mini
torch comes with either a propane set up or an acetylene set up.
I must say that with with the larger welding units, the fuel
regulators will fit either acyl. or propane even though you can
buy the tourch sets in either acyl or propane. Mapp is closer to
acyt. and is from my understanding, interchangable with it.

We use the propane/o2 for studio souldering and the like but we
use O2 and acyl. for melting for the castings (much hotter and
thus faster). Metal contamination is not a problem at all.
Presto lite units are good but the very small flame available on
the little tourch are not possible with these tourches, but I
think they are fantastic for silver work (lower heat but more of
it over a larger area than with gold). We do not work in
platinum so no comment there. John

John and Cynthia/MidLife Crisis Enterprises
Maiden Metals/C. T. Designs/ Bloomin’ Wax Works. etc. No one is
guaranteed happiness. Life just

PO BX 44, Philo, Ca 95466
gives each person time and space. It is
Ph 707-895-2635 FAX 707-895-9332 up to
us to fill it with joy.


#36
We use the small Little Torch with O2 and propane all the time.
Small tips work just great.  For those who do not know, the mini
torch comes with either a propane set up or an acetylene set up.

I have only recently begun setting up a bench in what was
formerly the back bedroom. I have deliberately chosen propane
because it burns cleaner, with less soot. I think it is a little
misleading to say the ‘torch comes with either a propane set up
or an acetylene setup.’ While it is true that the torch will
burn either, the setup is the same for both. Only the tips are
different. One wholesaler (Romanoff?) sells the torch for either
propane or acetylene, with a different selection of tips. I
bought mine from a different dealer, and decided I could live
with a couple of tips that I don’t use, because of the price.
Then there is the chance I might use acetylene occasionally.

I must say that with with the larger welding units, the fuel
regulators will fit either acyl. or propane even though you can
buy the tourch sets in either acyl or propane. Mapp is closer to
acyt. and is from my understanding, interchangable with it.

In talking with my local gas dealer, I was left with the
distinct impression that while there are some differences in
standard torch models for propane and acetylene, that either gas
can be used with either model, with careful selection for the
appropriate tips. It was my impression that MAPP is a sort of
’super propane’ as it is used interchangeably with small
plumbers/household torch kits. If it is closer to the BTU
output of acetylene, and is clean like propane, perhaps it could
be a comprimise indoors? Have you more on MAPP vs
propane vs acetylene?

We use the propane/o2 for studio souldering and the like but we
use O2 and acyl. for melting for the castings (much hotter and
thus faster). 

The very reason I may use acetylene … but not in the house!

Presto lite units are good but the very small flame available on
the little tourch are not possible with these tourches, but I
think they are fantastic for silver work (lower heat but more of
it over a larger area than with gold).  

Regardless of what some say, I am told by my local gas dealer
that a Prestolite ‘B’ torch can be attached to a standard
welding tank and regulator, with an adaptor for the line. I
have planned this torch as a later expansion of equipment.
Thanks for the comment on why you use the Prestolite!

<> Marrin T. Fleet <>
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#37

I have to buy a new torch set to use in my tiny apartment
because I lost the cheap lease on my jewerly studio. Is
Acetylnen dangerous? I always thought it was safer than propane?

DeDe


#38

I am told by my local gas dealer that a Prestolite ‘B’ torch can
be attached to a standard welding tank and regulator, with an
adaptor for the line.

True! The Prestolite torch is an air-acetylene torch. It can be
attached to any acetylene tank, ‘B’ ‘MC’ or any of the larger
tanks. All it takes is an adapter for the tank. Incidently, all
the tanks larger than the ‘B’ use t he same connection. The ‘B’ &
‘MC’ each use a unique connection.

FWIW

Prestolite is actually acetylene. In the early days of the
automobile in

the US (before electric headlights) the 1st headlights were a
large versi on of the miners carbide lamp. When calcium carbide
is mixed with water one of the products is acetylene. The amount
of carbide that could be placed in a headlamp wasn’t enough for a
long trip (who wants the lights to go out wh en you’re travelling
on a stormy night?). It was also necessary to clean out

the other gooey stuff (calcium carbonate, I think) from the lamp
before recharging it.

Well the folks at Union Carbide being clever people said, " Lets
package factory produced acetylene in a small tank." Well that’s
what they did, & the ‘B’ tank was born. Probably the name
’Prestolite’ too; from 'Presto &

the lights were lighted’ (could be?). If you see pictures of old
cars, prior to about 1915 look for the ‘B’ tank mounted on the
running board ju st behind the front fender. The gas was piped
from the tank to the headlights.

Dave


#39
I have to buy a new torch set to use in my tiny apartment
 because I lost the cheap lease on my jewerly studio.  Is
 Acetylnen dangerous? I always thought it was safer than propane?

Do you need new torches or just some very small tanks?

Dick Caverly


#40

Hi! I’m curious, I have friends who are using Little Torch, and
they seem to have problems soldering. Since, I’ve never seen
them solder; I have no idea what they are doing wrong (they
complain that items are not soldered.) I need to ask what size
your pieces are. My friends make LARGE pieces, and I’m assuming
that this may be the problem. I should mention that they work
with a variety of metals . . .fine silver (castings), brass,
copper, sterling silver.

I use a silversmith’s Acetylene torch and love it.

Thanks for any advice!