Because of my article on torches in Art Jewelry, I have just received
an inquiry about using MAPP gas for silver work. Is there any reason
it would not be OK? I’ve used it for glass, but never metal. An
expensive way to go, but should be plenty hot. Has anyone had
experience with it as a metalworking fuel?
Thanks-- I told my correspondent I’d get back to her,
Noel
Works fine, just as you noted more expensive and the extra heat it
produces compared to propane is probably not needed.
Jim
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
it is hotter than acetylene and oxidizes less than propane, is only
expensive in cannisters, not at the welding supply companies. MAPP is
a proprietary patented gas (I think it’s Bernz-o-matic’s brand).
I’ve used it for thirty years on silver, gold, platinum, and alloys
of most metals used in jewelry making. Strange, Nanz Aalund,
Associate Editor of Art Jewelry knows this and is their “resident
jewelry expert”…
Hello Noel;
Because of my article on torches in Art Jewelry, I have just received an inquiry about using MAPP gas for silver work.
I use MAPP gas in small bottles with one of those hardware store
burners, like the propane torch type. I only use it for annealing
large articles and sometimes for casting. Supposedly it’s a little
hotter than propane. I can’t see why it wouldn’t work with any
combination of oxygen, force air, inspirator burners, etc.
p.s. Sorry to hear about the plantar faschiitis, I had that once, it
was miserable, took my half an hour every morning to be able to put
my weight on my feet. Very painful.
As for that post on removing LOS from inside bezels, you are
absolutely right, and I caught that some posters weren’t answering
correctly. I was going to suggest those little fiberglass scratch
brushes, which work great, but I hesitate because tiny fibers of
glass floating around in the air are just about as bad as asbestos.
Better a little end brush in a flex shaft handpiece with some bobbing
compound.
David L. Huffman
Noel
MAPP gas will work just fine with silver I often use MAPP gas as a
substitute for propane in my Bernzomatic torch as it burns hotter
than propane. My Bernzomatic torch is the type that mixes the fuel
with ambient air, so it is not very hot and MAPP gives it an extra
boost. I have never tried MAPP gas in my Little Torch as the
oxy/propane mixture is hot enough for the type of work that I do, but
there is no reason that I can think of that would cause a problem
with MAPP and silver in a Little Torch
Regards
Milt
Calgary Canada
Because of my article on torches in Art Jewelry, I have just received an inquiry about using MAPP gas for silver work. Is there any reason it would not be OK? I've used it for glass, but never metal. An expensive way to go, but should be plenty hot. Has anyone had experience with it as a metalworking fuel?
Noel, I have used Mapp gas for years, mostly on the base metal I use
in making jewelry. I use the smaller tanks available in hardware
stores, which cost only a few dollars more than the similar-size
propane tanks. I understand that Mapp gas burns a little hotter than
propane (which is desirable for me because I make larger pieces of
jewelry and my solder melts at higher temperatures than most silver
solders). But I’ve not noticed much difference among using propane,
Mapp gas, or air-acetylene.
Obviously, the size of the flame makes a difference. Years ago, I
acquired a screw-on torch head with a small orifice for my Mapp gas
tanks, so I can use a small flame, more suitable for soldering.
Unfortunately, these are no longer available (to my knowledge –
Sears Craftsman made them originally).
On the rare occasions I work with silver, Mapp gas is fine. I just
have to be very careful not to melt the silver because I am used to
working with metals that have higher melting points. But that’s not
the fault of the Mapp gas!
Judy Bjorkman
Owego, NY
Hi Noel
I have used a MAPP gas torch which I purchased from Sears Roebuck in
1998 both in a jewelry store and at home ( after the store went
bankrupt). We used a Smith little torch for gold and the MaAPP gas
for silver.and this was perfectly satisfactory. The Sears torch
screwed into a portable MAPP gas cylinder.Sears stopped handling the
unit (even though it advertised a lifetime replacement guarentee)
and I have not seen a similar unit anywhere.Bernsomatic has one which
may be suitable ST900 D (no relation) but it has a long hose and
tends to fall over in use.
Tom
it is hotter than acetylene and oxidizes less than propane, is only expensive in cannisters, not at the welding supply companies. MAPP is a proprietary patented gas
Acetylene is the hottest available fuel gas, you cannot find
anything hotter but it is unstable at elevated pressure. MAPP was
designed to allow for running at a higher working pressure with
almost the same temperature as acetylene that some specialty jobs
require.
Acetylene max combustion temperature in oxygen 5720 F
MAPP max combustion temperature in oxygen 5300 F
Hydrogen max combustion temperature in oxygen 5133 F
Propane max combustion temperature in oxygen 5090 F
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
One should not run MAPP or anything through the same hoses as
propane EVER. you may buy a “y” connection at a welding supply and
run the two different fuels and one O2 cannister, but I think Smith
warns that it is not advised to use MAPP with their torches…though I
haven’t seen a smith torch in probably 5 years or so, but do recall
reading some warning on the handpiece at one time… R. E. R
Noel
http://www.uniweld.com/msds_sheets/G118.pdf
and you may also see some of the other sheets from other
distributors. I did not see one which said what the problem was with
using copper, copper alloys or silver, just that they were not
compatible. I did not pursue as I do not use MAPP.
Hope this helps
Terry
Thanks for the responses about soldering silver with MAPP-- I gather
it is hotter than propane, not quite as hot as acetylene, and should
work OK-- but with what torch(es)? Can you just use it with a Smith
or Presto Lite or whatever you have (with new/different hoses)?
Nanz raised the question (off forum) of worse fumes than other
gasses, so I need to compare MSDS’s, I guess, but anyone have more
info on this?
Thanks, all,
Noel
and you may also see some of the other sheets from other distributors. I did not see one which said what the problem was with using copper, copper alloys or silver, just that they were not compatible. I did not pursue as I do not use MAPP.
This refers to the piping the gas flows through. MAPP is modified
acetylene. Both Acetylene and MAPP will form acetylides with certain
metals. They are unstable compounds that can detonate if disturbed.
It does not relate to the use of the gas in a torch to heat these
metals.
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
One should not run MAPP or anything through the same hoses as propane EVER.
I have never heard this and suspect that it may not be correct. Both
propane and MAPP are hydrocarbons and hydrocarbons are generally
compatible with each other. Also I have used the same hose for MAPP
and propane on my Bernzomatic torch for over 10 years with no
problem at all. Has anyone else ever heard this before? Is it
possible
that you are confusing this with never running oxygen in a hose that
has been used for compressed air? The reason is that compressed air
usually has some oil in it and the which will burst into flames when
it comes in contact with pure oxygen.
Regards
Milt
I would add that your hoses should be rated for propane at a minimum
(type “T” I think). And a check valve to prevent the MAPP from going
backwards down the Propane line if using a Y connector. I also have
heard of a torch mfg. not reccomending the use of MAPP; specifically
the makers of the Lynx glass workers torch. Maybe conservative
caution on their part, having no field testing results from using
with MAPP?
Dan Wellman
Home Depot has MAPP gas hand-held torches that screw into the
cannister. You hold the whole thing up at once; no hoses. Push button
lighting on switch. Very convenient. It sounds like the thing Sears
used to have. I use one all the time and love that I can totally
ignite and extinguish with one hand. I think it is the same stuff.
Veronica
Thanks for the responses about soldering silver with MAPP-- I gather it is hotter than propane, not quite as hot as acetylene, and should work OK-- but with what torch(es)? Can you just use it with a Smith or Presto Lite or whatever you have (with new/different hoses)?
It will not work well with prestolite or equivalent acetylene-air
torches. MAPP needs more oxygen (air) per unit volume (3.3:1) to
combust than acetylene (1.2:1) and some what less but closer to the
amount needed by propane (4.3:1) so it will work in a air-fuel torch
designed for propane better than one designed for acetylene. There
are a few torches designed for MAPP of the 1 lb cylinder design
(Bernzomatic) but not many. It will work fine in any oxygen-fuel
torch. Hoses need to be rated for use with MAPP
Jim
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
I have never heard this and suspect that it may not be correct. Both propane and MAPP are hydrocarbons and hydrocarbons are generally compatible with each other. Also I have used the same hose for MAPP and propane on my Bernzomatic torch for over 10 years with no problem at all. Has anyone else ever heard this before?
The problem is that there are two types of fuel gas hose approved in
the USA for use on torches Type R and Type T. Type R is used for
acetylene and Type T is used for propane and other fuel gasses. The
problem comes when you run propane in the Type R hose it will eat it
and your hose will eventually fall apart. I have seen this happen
with some of my hoses before I knew there was a difference and it is
not an over night kind of thing but it does degrade it and make it
brittle. So you should verify that the hoses you are using are rated
for the fuel gas you are using.
Jim
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
James
The problem is that there are two types of fuel gas hose approved in the USA for use on torches Type R and Type T. Type R is used for acetylene and Type T is used for propane and other fuel gasses.
Thanks for pointing out that there are two types of fuel hoses that
are not compatible with all fuels. I was unaware of this. I had a
look at the Smith website. As you mentioned, they sell the T hose
for propane and the R hose for acetylene, they also sell a hose
“13254 -3-6” for “any fuel”.
I checked my Rio Grande catalogue and they also carry what appears
to be a fuel hose for any fuel for the smith torch (500-024). So I
suppose it would make sense to always order the “any fuel” hose as
there would then be no reason to worry about which fuel you were
using with which hose.
Regards
Milt
Calgary Canada
I posted this once before, here it is again for the newcomers, with
an addition for MAPP.
When you convert from Acetylene to Propane or any other petroleum
based fuel, be sure to change your hoses. Acetylene is not a
petroleum based fuel and so most hoses for acetylene are rubber. The
petroleum based fuels will dissolve the rubber over time, gum up
your gages and clog up any small tips.
Until recently, the tanks for acetylene did not have to be inspected
since the pressure was only 300 psi. The federal government stuck
their nose in the business, now there is inspection of Acetylene
tanks. Some of these tanks have been around for many years, the
earliest ones were filled with asbestos, (acetylene needs to be in a
honey-comb structure to keep it stable). Any asbestos filled tanks,
or dinged tanks have to be replaced. This has caused undue hardship
on the gas companies, they have to raise the price of Acetylene to
cover the price of the new tanks.
They are looking for a new fuel combination that will have the heat
of acetylene but not the cost. They are experimenting with
Propolene, Chemelene, etc, which are Propane with other fuels added
(Hydrogen, etc…) in order to get higher heats. All of these are
petroleum based fuels and will dissolve/make soft your hoses over
time. Hose replacement for the gas line is only about $8.00 for 8
feet of line.
Acetylene hoses are Grade “R” and fuel gases are Grade “T”.
MAPP gas is a combination of two gases, a Propyne-allene mixture.
Propadiene mixed with methyl acetylene.
Love and God Bless
randy
http://www.rocksmyth.com
Good Morning All,
The extensive discussions over soldering, melting, alloying,
casting, heat-treating, etc. these past several years makes it clear
that a good many of our correspondents are artists. Our good and
gentle colleagues who don’t consider themselves engineers or even
technicians and really don’t want to become such. I feel driven to
make a point that I hope will aid us all in understanding and
communicating the issues of gasses, torches and fire. There are
untold variations and details that some of us could haggle over until
the goats come home to Topanga, and I’m going to make some rather
loose generalizations. However, I’m not trying to whack the hornet
nest so let’s not get involved in details, just let me make a point
that I think will help.
A torch is a device for the controlled mixing of a fuel gas with an
oxygen source. The mixture ratio is controlled by the valves and
openings within the torch and the pressures of the gasses applied to
them. The volume of mixture or rate of flow is largely determined by
the opening in the nozzle and the pressure of the aggregate mixture.
We light the mixture where it comes from the nozzle to make a flame
for our use. Let’s look at the flame.
The flame is a jet of mixed fuel and oxygen which is busy combining
chemically, breaking down the fuel molecules to form a residuum of
CO2 and water and minor “impurities”. We are interested in the heat
that this chemical union produces and we are interested in two
aspects–the temperature of the heat and the quantity of the heat. I
realize that this concept has been abused in the last few decades as
marketing forces have pushed various new technologies. For example
when the neodynium-YAG laser was introduced to eye surgery it was
termed a “cold laser”, but, good heavens, in the few nanoseconds of
its pulse discharge at its microscopic focal point the temperature
reaches about 9000 degrees Kelvin.! That’s more or less the
temperature of the surface of the sun, but the quantity of heat is
infinitesimal. This is my point, think separately of THE TEMPERATURE
OF THE HEAT and THE QUANTITY OF THE HEAT.
The TEMPERATURE is determined primarily by the type of fuel and
ratio of oxygen in the mixture. The QUANTITY of heat is determined
primarily by the volume or amount of mixture being burned. Jim
Binnion has given you the TEMPERATURE that can be achieved by each
fuel gas when mixed with the optimum ratio of pure oxygen and when
mixed with the optimum ratio of room air. Clearly all of them are way
above the temperature you want your work piece to reach for
soldering, So how do we understand what we want to acheive and how do
we get there?
In the case of a solder joint we want to raise the temperature of
the joint and the solder to it’s flow point without overheating the
work-piece and slowly enough that we have time to think and react.
This brings up some more technical factors. The rate of heat transfer
is mostly determined by the temperature differential, as from the hot
flame to the cool metal. The distribution of heat that is transfered
to the metal is a function of thermal conductivity. Silver and copper
have very high thermal conductivity while gold (and especially
platinum) have rather low rates of conduction. Now lets look at what
actually happens when soldering with our trusty torch.
At one extreme is platinum. We play our torch on the joint, the heat
stays near the joint but we need to get it really hot, so we use a
very hot but rather small flame. At the other extreme is fine silver.
The heat from our torch is rapidly conducted away to heat up the
entire work piece. The whole piece gets hot but our solder flow point
is much lower than the platinum example. For the silver piece we need
a fairly large QUANTITY of heat but not a really high TEMPERATURE;
with these requirements a tiny, super-hot flame can get you in
trouble much faster the a larger, cooler flame.
Think separately of TEMPERATURE and QUANTITY, it may help you (I
hope so).
Dr. Mac