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
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…