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Precision LP torch

Dear Margaret,

That Smith acetylene torch is not supposed to work like that, at
all. If new get a hold of the Smith people, it has a lifetime
guarantee, a real one. If you got this second hand and cannot resolve
the problem my advice is to get a new handle only part #- NE180A. If
any future problem occurred you will have a lifetime guarantee.

As for the Precision LP torch, if you own a Smith air/acetylene and
a little torch you have no need of this. I am a fan of it but there
is no way I would tell anyone that they should scrap their Hoke,
Smith, Meco, etc. I will say it is nice and it will take care of
business. Furthermore if you have a gas restriction problem this will
definitely solve that. All those universities, colleges, and trade
schools that teach gold and silversmithing that have opted for this
is not without reason. It is also an easy torch to use, and it dose a
nice job. The Adelaide Institute of Tafe at the Roma Mitchell Arts
Education Centre -Visual Arts (Australia) uses 36 LP Gas Torches.
This also answers the question of why is the no. 3 tip optional,
obviously they don’t need that tip for every one of them.

I belong to a club so I have used air/acetylene, but wanted
something for home use. I have gas restrictions. This solved my
problem. What this thing really is, is a goldsmith’s torch, although
it works nice on silver jewelry construction. In trying to find
something that would work for me I came across some sites in German
with a mention to Rudhard torches, so when I found they make this I
knew I had a known product, it’s just not known here. The reason for
going through the agents is that the manufacture dose not speak
English. I had a nice letter with my torch; I have no idea what it
said. As for performance figures (condensed):

We read through all your e-mails and rang the manufacturer again to
clarify a few points. The goldsmith, who has performed the tests for
him stated: " To achieve a repeatable test result for everybody he
can guaranty that you can melt 50-60g of Sterling Silver. I have
successfully cast 90g of Sterling Silver. That depends on skill,
technique, the crucibles and the different alloys. The manufacturer
mentioned again 1200/1250�C as maximum temperature LP Gas Torches can
achieve. This morning we did some test melting of various white gold
alloys. We were able to melt 14ct palladium based white gold, which
has a solidus of 1145�C and a liquidus of 1225�C. We could not melt
18ct palladium based white gold, solidus 1272�C.

As for a few comments, the 90g for silver is not an absolute limit,
as I wanted to know a practical amount. Also if you use casting grain
from the Rio Grande catalog you should be able to have a larger
practical pour than with what they used. Rio Grande sells a palladium
14ct white gold casting grain. Casting temperature is 2150F or
1176.67C this will cast that. Mapp gas can be use for a hotter flame,
although I have no data the boost should be somewhat like some other
torches, but anyway whatever, it will be hotter. I was assured that
that would not be needed and it’s not. The solidus is the melting
point and the liquidus is the flow point. I hope this will answer a
few questions about what this is and what it is not, it’s main
strength is in the detail work that can be done. I have no financial
interest in this, I do write some. I will say that I am glad I found
this as it solved my problem.

Lastly I will give directions on alloying as they are the best that
I have seen and good advice with any torch used.

We have successfully cast silver and gold alloys for normal workshop
applications. As for gold we are usually alloying around 30g 18ct
Yellow Gold at a time, never experiencing any problems. Alloying
Sterling Silver requires a large amount of heat over a longer period.
Always preheat the ingot to let the moisture evaporate to a bit more
than hand warm, then preheat the crucible until the inside is
glowing. Remember to melt the fine silver first and then fill in
slowly the borax coated fine copper (preferably small and thin
pieces). Keep the crucible moving to ensure the formation of a
homogeneous alloy. In addition use a graphite-stirring rod to stir
the molten metal, to assist in mixing. This also helps to detect
solid copper parts. If necessary add a little more borax powder and
keep heating until the metal displays a mirror like surface and moves
around freely in the crucible. Make sure to keep the distance between
flame and metal the same while moving the crucible towards the ingot
for casting.

Unsuccessful melting of metal is usually caused by: An incorrect
distance between flame and metal, flame too small, crucible not
preheated, copper added too early, no flux used or draught cooling
the surface.