Please can someone help
What is the latest greatest casting system available. I am tired of
searching for bracelet and charm castings. I would want to do my own
designs geckos lizzards etc i want to start a retirement business
any suggestions? im in South Africa
Frank,
“Greatest casting system available” depends on your definition of
"great".
AFAIK, the 4 most common systems for casting silver are as follows:
Lost-wax method. Advantages: details perfectly preserved, infinite
copies of same article possible. Disadvantages: large amount of
infrastructure and training required, high hazard of silicosis from
investment powder. Although I do suggest “Handbook of Lost Wax or
Investment Casting” by James E. Sopcak as a good start if you want to
create your own equipment.
Cuttlebone casting. Advantage: simplest and least expensive entry
pathinto silver casting. Disadvantage: only one-of-a-kind designs
are possible, this path only good for artists or small operators.
Also uses cuttle-fish bone, so not suitable for those people with
strong feelings about animal rights.
Dine’ style casting. This is the method I use. This is a drop
casting method that uses cakes of very fine volcanic pumice, known
as Tufa, as the mold material. The artist carves the mold out of the
cake and pours silver into it. Advantage: simple, effective, elegant
and safe, used for centuries by indigenous peoples in the American
south-west. Disadvantage: mold material is highly delicate, about 3
times harder than talc, and crumbles easily. Details good to only
1/100 of an inch. Very difficult to hand carve since material is so
fragile: I get around this problem by using a CNC milling machine to
do my carving for me.
Precious-metal clay. This will be my method of choice for
embedding some gems. Although this is sintering rather than casting,
some of the results of casting can be simulated using this method.
Advantages: takes impressions to high amount of detail.
Outstandingly simple to work into shapes.
Very good method for limited applications. Highly suitable for rapid
prototyping of jewelry. Disadvantage: Material is roughly twice as
expensive as market price of silver.
You pays your money, and you takes your chances.
Best,
Andrew Jonathan Fine
Andrew that is a lot to digest and research but thank you very very
much it will get me going i will need a lot more help as i get going
thanks once again
Frank
the 4 most common systems for casting silver are as follows:
Most or all of what Andrew says is correct, as far as it goes.
First, I know there are quite a few PMC fans here, and good for
them. To me, the disadvantages far outweigh any advantage. And it’s
quite a stretch to call it casting…
But to elaborate on Andrew’s writing… There are several broad
familiesof casting, and sometimes they overlap each other.
The biggest division is gravity pour or mechanical assist.
The next division is the molding medium - sand, investment, tufa,
and many others. Anything that can take the heat, basically. You can
pour a slab of investment and treat it like tufa, if you want to. If
I said that nobody but jewelry students use cuttle bone, I’m sure
people will start popping up who love it, but I said it anyway.
The problem with gravity pour is that you have an upper limit of how
much detail you can get. Though the saying goes that you can cast
anything if you sprue it properly, that also means using the right
mechanism for the job.
The problem with sandcast and tufa (and similar) is that you can’t
have undercuts (well, a bit with sophisticated sand casting). It’s
suited to casting something like a coin or signet ring. So, if one
wants to cast simple shapes with moderate to low detail then sand or
tufa is a tried-and-true and cheap option. Sandcast can use a model
to do production (though they usually call it a pattern in sand
casting), tufa must be carved every time or a couple of times,
maybe. (as does cuttle bone). You can also in vest a flask, burn out
the wax, and gravity pour that - that works less well than sand
(sometimes not at all) because the sand breathes better than
investment - but it can be done…
The oldest mechanical assist is probably getting a flask on a rope
and swinging it around like a yo-yo (obviously a dangerous practice
nowadays). Centrifugal and vacuum casting are the two widely used
methods for that.
Usually they are investment cast, usually but not always lost wax.
Those will give you high detail and all the undercuts you want, they
also require an investment in equipment and a moderate learning
curve.
You can sandcast with $10 worth of sand and some 2x4’s, along with
the melting system, if that’s all you want to do…