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Vacuum caster/Electromelt reply


#1

Hello Ken From MPG repair… I will try to explain better what Mr
Morley meant in his statement and explain to you exactly why We can
cast better with the eye than the elctromelt. I take great affront
at a statement like "call, like me, who knows how to solve the
problem properly. " and by reading what I have to say about it,
perhaps you will understand my statement.

First and foremost, I sold electromelts for 10 years as a
salesperson… They require calibration the day they are bought and
most people don’t know this… or how to do this. I had hundred s of
calls precisely due to this problem. I was also the design
engineer for the supply company that was selling them. I did not
design The electromelt . I did design lots of equipment presently
used in the Jewelry industry, and I was the first person to develop
heat cured silicon rubbers in sheet form for the Jewelry
industry.The other companies copied the rubber 3 years after we
proved it to be quite successful.A lot of other things were designed
by me as well.

As far as experience goes… I’ve got nearly 35 years in machinery
design and repair as well as being a caster who has used almost every
piece of equipment on the market Since 1968. Most of the electromelts
sold are not properly calibrated… They also have an overshooting
problem… If you want 1825 oF , It will more than likely over shoot
this figure by a good 100 to 150 oF… The manual versions are the
worst. The controller is a bi metalic switch and that is in no way
accurate. Anyperson proficient with electronics will back that up. You
can eventually get control of the overshooting problem by carefully
watching the temp as it approaches temperature and backing off the
temp . The digital ones are slightly better, but they still overshoot
the metal temp. Again, You can " learn " to use it with expereience
and some bad castings. You cannot Nail the temperature any better
with this machine than I can by eye… …Actually, I can do better
! Now, let me explain the reasoning

I’m not superman, I don’t have x ray vision… I have tricks and
knowledge that works and I’m willing to explainhow this is done
without being superman!

Simple really… When an electromelt is melting, due to the
tremendous glow generated by the graphite crucible, the metal is not
easily seen with the eye wearing protective eye wear., so you have to
use the gauge on it, no matter how inacurate… Your graphite
crucible ( cost $30 approx) deteriorates as the melt progresses…
Where does this deterrioration go? Specially if you do not use
flux… which you shouldn’t … It goes into the button of

your metal … So you get small amounts of contamination, which
reduces your ability to re-use your metal… All machines that use
this type of crucible have this problem… even if they have a gas
coverage !!! Gas coverage reduces this but does not eliminate it.
Aks anyone who sells machines that use graphite crucibles where the
deteriorated material goes and most will side step that question
very quickly as there is only one answer…

Now, We go to torch melting. First, we set it up as I explained to
Mr Morley… You buy a $29 microphone stand from Radio shack. this
will be your torch holder… make sure you bring your torch so that
you get the correct plastic microphone holder for it… there are 3
different ones.They cost about $3. Now, You buy the ceramic crucible
holder/ handle from Contenti supply ( 800-343-3364 ) there are 2 . a
large capacity and a smaller one. This is about $15. The large
ceramic crucible fits the larger handle. Crucible is about $ 8 and
last a year or more… depending on use and how you treat it. Get
some flux and flux the crucible. The large crucible is capable of
melting just over 700 grams of silver and the torch can have that
ready to cast in under 5 minutes Pre heat the crucible for 3 minutes
at high heat with the torch. Put your metal in the crucible, slight
amount of flux added and melt away… If you are melting 400 grams ,
you will be ready to pour in about 2 1/2 minutes or less… so don’t
leave. As the metal is approx. 3/4 melted, Move quickly as this is
crucial…

Now, You are ready to cast… With the microphone stand holding the
torch , you have both hands free… Reach into the oven ( with tongs)
remove the selected flask , Place it on the vacuum table( seal in
place) turn the vac. on . You can now remove the torch from the mic
stand , Pick up the crucible holder, keeping the flame on the
metal… As soon as the surface of the metal is clear and bright (
looks like Liquid Mercury) pour the metal into the flask. Doing it
this way, your as close to the exact metal temperature as you could
could possibly get … This works with all metals from gold to
bronze, silver, pure silver, pure gold etc… No, You don’t need to
tell what the temperature is in degrees… and the reason is that
you poured it just at the

point where the metal is clean and perfect ! . Now, Here is another
advantage to this… The reusability of your metal ! It can be reused
many times … 2 to 3 times without adding fresh metal… again, the
reason is that the metal temperature never over shot by 150 degrees
before settling down as it will do with electromelts and many of the
expensive casting systems using medium frequency and high frequency.

Older metal needs to be slightly hotter to get good castings… It
is still cast when the surface is clean with a torch. With an
electric melter, you have no idea where it should be if it is older
metal ! Only A few machines have the ability to sense the approaching
temperature and lower the power so that the metal does not over
shoot the temp. Rio Grande carries the Neutec which is one of the few
machines that has this feature … But this is expensive… so is the
leybold herreus machine. They are the best in their class.The
electromelt does not have this ability, so you must relly on the
operator to do this function… and you can’t get it as perfect as I
can or Mr Morley can .We can see the metal as it clears and becomes
ready to cast. We also get Zero metal contamination.

So , as you can see, this is more accurate if the operator is
watching the metal… It is also about 10 times faster than the
electromelt and due to the

microphone stand, you are casting literally within seconds of when
the flask is removed from the oven… so your flask temp is also more
accurate than can be achieved with centrifugal machines and the big
fancy machines. We can melt down 300 grams -400 grams and pour the
cast in under 2 minutes.

Is it superior to an electromelt… Yes. I have personally taught at
least 100 people to do this and they all have excellent results if
they follow the directions. The cost savings are tremendous… What
you spend on one graphite crucible is far more than my oxygen and
propane tanks cost to use for2 weeks

of casting on a daily basis… more than 30 large flask per day…
You would be using a crucible per day ! On an average, we cast thick
and thin items dayly … up to 5000 pcs in one day and the castings,
when finished are the best most peolple have seen in a long time. We
do trophy handles that weigh up to 1 1/2 pounds clean ! trophy
handles are some of the most difficult things to do… We also cast
very thin wire woven designs for some of our customers with excellent
results… results that they didn’t thick was possible…

Sorry for the long rant, I just don’t appreciate anybody implying
that I don’t know what I’m doing or that I don’t know how to adjust
and make an electromelt work… I certainly can, but, it comparison
to my system, it’s a waste of time and good money !Any person
casting can follow my suggestions above and they will get great
results just as Mr Morley does.

Sincerely, Daniel Grandi

We do casting and finishing for designers, jewelers, and people in the trade
as well as enamel, plating, soldering, fusion, hand finishing , vibratory,
volume stamping, hand made models, cnc models , antiqueing, and a
whole lot more… Contact : sales@racecarjewelry.com