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Torch of choice for alloying


#1

Again, I read with great interest the original fabricating thread.
Now I am curious, for those of you who do alloy and melt metal into
ingots, what is your torch of choice.

How many torches do you actually have? What types are they, and
which do you use for what?

Torches have, in the past generated some very strong opinions. I now
wonder if some do not alloy and melt, because of torches on hand?

Access to gases, torch tips, adequate heat?

Hugs and Thanks,
Terrie


#2

Hello,

I am a novice, but I have found that propane/air seems to work okay
melting up to a few ounces of gold and silver. Anything that melts
over 2000F, it doesn’t do a very good job. If you want to work with
any of the platinum group metals or higher melting materials, you
really need to use oxygen with the gas if you want to use a flame. I
know some people don’t like oxy-acetylene because of the carbon it
can introduce, but this is a relatively cheap, commonly available
torch that will melt almost any metal you require. Perhaps
oxy-hydrogen would be best since it emits a tremendous amount of
heat, but is very clean. The thing with hydrogen is that they
regulate the sale of it in many places much more than the
oxy-acetylene. I have used oxy-propane,and it works fairly well. The
heat is not as intense as oxy-acetylene, but it is fairly clean and I
have melted small amounts of ruthenium and palladium with it.

This is just my experience.
Thanks.
Seech


#3

Hi Teresa, I use an oxy-acetelyne torch for melting alloys,
mud-bathing silver rings, and the occasional fuzing.

The LPG gas torch with a medium nozzle does everything else. Tried
the mini-torch and found more weaknesses than strengths.

Alastair


#4

Alastair,

is there a name to this torch?

Thanks,
Terrie


#5

Never use Acetylene with platinum. It instantly contaminates the
metal. No how No way… Source Platinum guild International (PGI)
and email Yergen Maersk for more technical notes regarding this…


#6

Teresa, the name of my torch…the oxy-acetylene torch was purchased
as a kit in Australia. Named ‘Colt’ from Cigweld (now BOC) it is
intended for light trade or home handyman duty and includes the
handpiece, hoses, heating tips, cutting tip, and gauges.

My gas torch is ‘Primus’ (also made in Australia), the common full
pressure LPG gas/air type, the handpiece is quite big, and the 1cm
diameter nozzle produces a flame adjustable from 1cm long to about
20cm long.

By the way, I have a painting on the wall of a man in the 1800’s
soldering jewellery in a charcoal brazier and using a hollow reed as
a blowpipe to fan the fire where needed. It’s there to remind me
that there are many ways to do the job; just that some ways are
faster!

Cheers, Alastair


#7

Alastair,

Jay Whaley taught a class in China a couple of years ago. He was
amazed at what they did and with what.

Last semester, he had a student born in Iran. She brought in her
blow pipe torch to show us what she regularly used. Quite a
contraption.

So your LPG gas/air is the torch used to melt metals?

It is becoming very apparent, that some strong defenders of certain
torches, do not melt metal. Within the strength of these arguments,
I have not seen that addressed. So it is clearly an issue of what you
are using your torch for, not what is the best torch.

Think it is time to look at online catalogs, from other countries.

Hugs and thanks,
Terrie
Jay Whaley’s Studio Assistant


#8

Hi Terrie,

For melting of metals such as sterling or gold alloys for casting
ingots in amounts less than about 30 dwts, I use a Harris model 16
torch with a rosebud tip. This torch is excellent for melting,
alloying and annealing gold and silver, but for platinum or large
quantities of other metals, it’s not quite up to the task. For the
shop that doesn’t do platinum casting or melting of more than 30 or
35 dwts at a time this torch is ideal. It’s a real gas/oxygen
internal mixing torch handle with a tube and changeable tips, but
it’s smaller and much easier to handle than most, making it very
useful, user-friendly and efficient in a small shop. I got mine from
Gesswein.

I use a Meco 63103 Weldmaster cutting torch body with a custom tube
and modified rosebud style tip for heavier melting such as platinum
or more than about 30 dwts of other metals. It really cranks out the
BTU’s. This torch was custom built and given to me by my brother.

So it is clearly an issue of what you are using your torch for, not
what is the best torch.

In my humble opinion, there is no such thing as “the perfect torch”,
only as you say, the best torch for the job at hand… My experience
is that it should take less than thirty seconds from the time the
flame hits the metal to the time it’s ready to throw (or pour)
without having to use too much oxygen (and using a pre-heated
crucible). Any longer (or using too much O2 as a way of increasing
heat output) causes problems with porosity in castings and ingots
that will crack and split due to “cooking” the metal, burning off the
zinc and oxidizing the melt. Too large of a torch can cause the same
results, but more because of getting the metal too hot rather than
from heating it for too long.

I run all of my torches with LP and O2. I find that LP has a good
balance between cleanliness and heat production. I also use arrestors
on every torch.

Hugs back at ya!

Dave