Tack II spot welder, Jelenko Thermotrol Centrifugal Casting Machine, Kerr Automatic Electro-melt Furnace, Ultrasonic Cleaning Machine & a RayTech Tumble Twin Rock Tumbler as well as a Jelenko LFC Burnout Furnace is what I have access too - i want to cast small things and gold teeth… will these tools work?
As long as they actually work; it’s a good start. I’m surprised you don’t have a vacuum assist table available as well.
I’d definitely do some practice runs before doing your real projects first.
So yes and have fun!
i’m completely new - would you specify which one of these tools to buy? there from a jeweler who referred me to this site and they have been sitting in his basement. He stopped casting being he was sending it all out. I want to really focus on gold teeth & customs.
I think your best option would be to read through the description of centrifugal casting on line or in an older jewelry text like the one by Murray Bovin, which can be found in many libraries. Bovin actually describes and illustrates some of the old casting machines such as you mention. You may also find them profiled somewhere on line. If they work, that is good…finding spare parts and repair at present is difficult. You have the burnout oven and centrifugal caster, but you would also need to make wax models and possibly also molds of some kind, so you would need to look into the hand tools for doing that. Also, probably, as someone suggested, a vacuum table or some substitute method. This is all covered in Bovin or in Sharr Choate’s book or any other comprehensive jewelry text. Once you have an idea of how the whole process works, you can decide on what tools you might need. I assume you would carve waxes rather than use a jewelry CAD software to produce them…but that’s another whole issue to explore. You would also have to look at finishing methods and tools, such as a buffer…
…bottom line is that you need a better understanding of the whole process and how it all works in order to know what you have already and don’t have, what you would need or want to get and what questions to ask about all that. You just need to spend a few hours figuring all this out. The archives here may help with some questions. Then give us another shout. It really isn’t possible to completely answer the question you are answering until you are clearer about what you want to do and how you want to go about doing it. HTH, royjohn
You don’t mention any handtools, torches, polishing lathes, Flex shafts, files and more. Do you already these tools and some experience using them or are you just starting out?..Rob
i can easily obtain those, i know which tools to buy from an experience repair jeweler - he does not cast: he told me to learn basic casting and he will easily teach me polishing etc & basic repairs
i just want simple casting of gold, from melting it, handling it, pouring it, curing it then the rest is detail work to finish it/ polish it
Royjohn makes several good points in particular to the question of working wax. You seem to want to start in the middle from a skills and experience point of view. Understanding precious metal, how it behaves and how to manipulate it towards a desired end takes time to learn and regardless of what you want to do, you need this experience. Start with fabrication, forging finishing . You may be able to learn these skills from your friend. Move on to doing simple melts and making ingots. Then how to roll, draw or forge these ingots into a shape that you can work with. By learning these skills you will begin to learn how precious metals behave when you start to cast them. Casting is a fairly technical skill and many on this board concentrate on the more creative aspects of model making and then send the waxes out to be cast by someone who only casts. You can also get a feeling for how precious metals behave when cast by learning to work with Delft Clay. Good luck…Rob
Not trying to be obstructionist here. I think Rob makes some good points. Let me go back to your query…“simple” casting of gold. If you had a flask, then you would need to know about melting and pouring the gold, getting the casting out, desprue-ing and finishing. That sounds simple, but the devil is in the details. Your burnout procedure and flask temperature, your pouring method (use a torch or an electromelt?), your desprue-ing method, your finishing methods (mass finishing or filing/buffing?). And we are not even addressing your flask. There is the issue of how you are arriving at a wax. I presume you want to carve custom waxes…so there is the choice of wax(es), the method of buildup or carving you will use, the types of tools and heating methods and the finishing of the wax. Then there is the spruing of the wax(es). Then the mixing of investment and its proportions, the exclusion of air or use of a shell method, painting on investment, the pouring of the investment and curing of same. So there are details at every stage and it would run to several pages to even begin to describe all of this. Hence my suggestion that you look on line or in books for a description of this process. Once you are clear on how all of this works, you could ask more intelligent questions about the details of what you are going to cast and finish. Some of the answers you would find in the archives here, once you knew what questions to ask.
As to wax work/carving, there are whole books on that subject, including Kallenberg’s, which is a classic, and several others. Perhaps someone else will chime in here and tackle your question. I think it will be far more enlightening, as I said, for you to read or at least skim over some books or on line essays on the subject of lost wax casting. Google is your friend in this. -royjohn
The appropriate literature of casting was ordered. As far as waxing, build a spruce and all else - I understand those basics. As far as impression kits, compound to make teeth; I have those - a bunch of experience with mixing on how to achieve the perfect mold and apply wax to settle then carve. For me that’s the basic. The more advanced would be in regards* to the burn out method being I’ll most likely for this application be using a melting furnace and pouring the liquid gold into it. Then once that solidifies - breaking it from the compound & then its on to the finishing work. Again let me make this clear* being I’m new to this. I’m literally looking for the tools* of what one would prefer to utilize to melt the gold, hand the melted gold on so forth. All responses so far are appreciated. I want a simple method to start* then as I build confidence can work towards the more advanced.
Thanks for that Rob, I have seen deft clay in many videos in regards to this as well. I will look more into this.
<<The more advanced would be in regards* to the burn out method being I’ll most likely for this application be using a melting furnace and pouring the liquid gold into it.>>
I’m not completely following this. I’m guessing that you’ll use the burnout oven you have to burn out the flask and put the flask into a centrifugal caster that you have. You can pour from a crucible or from an electronic melting furnace. There’s some info on both methods in the archives here. In the interest of simplicity, I’d go with an electronic melting furnace. These are available from jewelry supply companies or on ebay. Prices $250 or so on up to $800. These are a little simpler to use than trying to run the centrafuge, hold the torch on the metal through the pour and pour the metal into the flask. Albeit a bit more expensive than a simple crucible.
I have not checked, but I think you will find some Youtube videos of centrifugal casting that will walk you thru the steps. I do know that there are some videos of the metling furnaces.
Good luck! -royjohn
ok, so…is your process generally something like this?:
you are going to take impressions/ make a mold of a person’s teeth, …then…make a plaster(?) cast of the teeth(?) like dentists do?
then use the plaster(?) cast as a model to make a wax shell/ sheath of the front of the teeth…or something like that?…a “grill”…?
(look into wax build up techniques?)
(perhaps look into wax pens like the kerr ultra waxer…and perhaps dental wax modeling techniques…?)
then invest the wax “grill” with investment in a flask, using investing apparatus
then burn the wax out of the flask in a burnout furnace
then melt the gold in an electric furnace
then use some sort of casting apparatus to get the gold into the flask
then drop the flask in a bucket of water, to break up the investment (thermal shock)
then clean up the metal casting
grind off the sprues
work through progressively finer files/ abrasives and polishing compounds to get to your desired finish
one thing i could add to the comments is this…since it seems like “fit” might be critical…you could research “shrinkage” as it applies to wax models and casting
i am not sure if there is any shrinkage after you remove the wax grill from the plaster(?) cast of the teeth…
as you “finish” the gold teeth, you will be removing metal and that may affect the “fit” as well…
you make a wax model (for a gold piece, not teeth, which i assume are “one offs”…)
you invest it, burn it out, and cast it into gold
you finish the piece and it gets smaller
then you rubber mold the finished gold piece
and then cut the mold open to remove it
then you shoot a wax replica in the rubber mold and remove it, and it will be smaller
(the rubber compresses after you cut the metal piece out of it)
then you invest the wax replica, burn it out and cast it into gold for a second piece
then you finish the piece and it gets smaller still…
the second generation metal is smaller than the first generation metal
…shrinkage might be an important topic for you…
also look into “progressive solidification” as it applies to casting and sprueing…it seems like the wax “grill” will be very thin…and long…
sorry for the ramble…just thinking out loud…
yes it is, thank you for that information - very helpful
We used a Jelenko Thermotrol Centrifugal Casting Machine for many years, before platinum became so expensive. It has a heating coil wound with platinum. This would burn out at least once a year. Back in the 80’s it cost over $800 to have rebuilt by Romanoff. Don’t know if they can still be rebuilt. Heat is very accurate, but melts very slow. Take the heater apart, send the platinum to a refiner and buy a small torch melt caster.
You might find Bobby White, of London, interesting…check out his youtube channel videos…
he came up in the industry
is a focused, meticulous, very skilled, unique visionary
he has a tight but very well appointed studio
i think his best(?) friend…or brother(?) is his partner and does CAD
(check out his studio video)
he creates very interesting, unique pieces
his videos show process while also communicating who he is…where he came from…what he is about…
i love him!
this ring is crazy…
(he is in a different studio than the below studio tour?)
here is his story…
here is his studio tour…this earlier studio is tighter, more pristine one than the one shown above, which has more employees? more stuff…
Its good to hear that you ordered books!
Hooefully you should be able to learn alot and understand the whole process better.
i love reading big thick technical jewelry technique books!
which ones did you get?
See, the thing is…there are so many rabbit holes to burrow into…it is hard to cover everything…
just take the metal, karat golds for example…it is an alloy of pure gold, combined with other elements to create the different karat qualities…but what you combine it with makes a difference in the color, the working properties of the metal, etc…sometimes to get the desired color, you sacrifice other things like malleability…melting temperature…you may not end up alloying your own gold…but it would be good to understand the different properties of the different karats and colors and how that works with your desired end use…so that you choose wisely
ie: nickel, which is white, is sometimes added to gold, which is yellow, to make it whiter…some people are allergic…sometimes its not the best choice for cast designs with big prongs…some people rhodium plate white gold to make it a brighter white
ie: rose gold has more copper added to it, to make it redder, it is pretty but has different working qualities from yellow gold
ie: pure gold (and pure silver) is soft, often too soft for jewelry use…elements are added to raise or lower the gold content to get 18 karat or 14karat…18 karat gold has different working properties than 14 karat…
depending on your desired outcome, sometimes casting is the better choice…sometimes fabrication is the better choice…cast metal is different from milled stock…the molecular structure is different
ie: a cast ring ends up with a different metal structure than a cast ingot that is then forged, then rolled down into strip or sheet stock, and/ or then drawn down into wire, and then possibly annealed…
as you work the metal, the molecules re-align…and get more packed together…eventually the metal will stress/ crack/ break if you go too far…to keep working it/ shaping it/ bending it, etc, you have to relieve the stress build up in the metal by annealing it at the proper intervals…still, cast metal is different from milled and worked stock
you can mechanically finish metal in tumblers etc, but only the surface is hardened by the burnishing action of the media…not all the way thru the metal, like forming or forging…if that makes a difference to your desired outcome
also tempurature is another consideration…at what temp the metal needs to get to…to anneal, solder, fuse…or completely melt it and hold the heat long enough to pour it…
not to mention making sure the crucible is hot enough to hold the heat while pouring or casting…or if the flask is the right tempurature to recieve the metal…
also as metal flows, into the flask, it is starting to cool…so you have to plan your design, and sprue connections to allow for successful fill of the metal…it can freeze in a tight bottleneck and not allow the delivery of metal to the rest of the mold…progressive solidification…sharp turns create turbulence in the flow of metal…turbulence can crash into delicate detail parts of the flask and break off investment which then gets into the metal…
getting a great casting can be simple in theory and complicated in practice…you can get incomplete fills, rough surfaces, porosity…
the dreaded porosity…pits, holes
also…how the metal affects finishing…take sterling silver…it is harder to get a high polish on dead soft silver than it is on half hard or hard silver…again molecules…
the rabbit holes are many…all very interesting…i have just skitted along the surface…i am mixing metaphors!
alot of this can be learned thru books, etc…but experience, practice, and experimentation…getting the mileage…muscle memory…repetition are your best bet…and more fun in my opinion!
just my ramblings…too much coffee this morning!
If you want to focus on gold teeth and customs I highly recommend that before you start investing large sums of money in tools and machinery that you spend 6 months to a year working in a dental lab. The pay will be shitty, but you will learn more in 1 year than you would in many years of reading books and watching videos. You will also avoid making costly mistakes. By doing this you can dial in exactly what skills you will need as well as the tools. Most importantly you will also learn how much different dental alloys, tools, and procedures are from jewelry making. My husband and I have combined over 90 years in the high end custom jewelry world. We also both make our own gold teeth and eyeglasses. Best wishes on your journey.
I hope this is not considered a thread highjacking.
If so I, hope the admins can move this to another thread.
Here it is:
I’m not a jeweler, at least not yet, I’m just a guy with a mission, ref my first posts.
I have been reading extensively, and hopefully learned a thing or two.
My question of the day is:
How do you buy your metal?
I have seen videos of people grab a piece of sheet and start working. And I have seen people melt a bar and hammer/roll it to size and go to work.
What is your most common scenario?