Talk to me about the different ways to make rings

[Imdanny]

Let's assume a band ring, to make it simple.

There is "CAD/ cast"? Yes? What is this? What does "cast" mean? What is the alternative?

What does "handmade" mean in terms of the actual process?

How is any of this different than taking a tube of metal and sectioning it, then punching a hole in the center, and polishing up the rest?

There is a process of pouring liquid metal into a mold. What is this called?

Any information/ thoughts appreciated.

Thanks.

 

[TheDoctor]

Let's assume a band ring, to make it simple.

There is "CAD/ cast"? Yes? What is this? What does "cast" mean? What is the alternative?

What does "handmade" mean in terms of the actual process?

How is any of this different than taking a tube of metal and sectioning it, then punching a hole in the center, and polishing up the rest?

There is a process of pouring liquid metal into a mold. What is this called?

Any information/ thoughts appreciated.

Thanks.

CAD is Computer Assisted Design.
Models made in association with CAD are milled using CAM (Computer Assisted Milling) equipment and the CAD software.
Those models are cast in precious metal through a process called "lost wax casting".
Essentially, the models are covered in a sort of plaster called "investment" and, when the wet plaster dries, the trapped model is burned out of the plaster enclosure which creates a void within the plaster mould...matching the exact size and shape properties of the model.
This is done in a kiln at 1350 degrees F over several hours.
The appropriate amount of metal is then melted and poured into the hollow cavity in the mould.
How the metal gets into the mould deserves longer explanations but you can Google Lost Wax Casting or even watch it on YouTube.

A simple band doesn't really require this process but many are done this way. One example of handmade, in reference to your question, might refer to a fabricated band, made by shaping bar stock of the requested metal into appropriate dimentions and then bending it into a closed circle and welding the joint. These can generall be stretched or shrunken with very little effort and no expensive machinery. They are then shaped and polished
Most commercial bands are die-struck, meaning they are produced from metal blanks stuffed into specially shaped steel "dies" with the aid of a really powerful press. (The same way coins are made, just different dies).

Metal tubes and rods are often used in the manufacture of bands made with materials which don't respond well to other forms of manufacture. For example, special platinum alloys can be created with very expensive industrial processes but can't be melted and used in regular casting applications because the alloyed metal/chemical combination become unstable under regular manufacturing techniques.

 

[JewelFreak]

Really good questions, Danny -- and thanks for the info, Doc.

--- Laurie

 

[Imdanny]

Thanks, Laurie! Thanks, Doc!

Any guesses as to how this ring was made?:

http://www.tiffany.com/Shopping/Item.aspx?fromGrid=1&sku=GRP00364&mcat=148204&cid=288152&search_params=s+5-p+1-c+288152-r+101323339-x+-n+6-ri+-ni+0-t+-k+

 

[Lady_Disdain]

My guess would be either cast (from a master mold) or fabricated. If fabricated, then wire was drawn through a drawplate with the right profile and then cut, closed and soldered. Mind, jewelers have some strange ideas about what is wire: a 5mm by 5mm square profile would be called wire, even though you have to whack it with a heavy hammer to get it into any shape.

 

[JewelFreak]

I'd imagine molded, since it's Tiffany & they produce thousands a year, probably. Any other way would be too slow & expensive for a plain band.

 

[Michael_E]

"CAD" is a method of modeling all sorts of things, some of which can then be made directly from the model. I worked as a machinist for a while running CNC machines, which could create parts directly in metal from CAD models. I have worked as a machine designer as well using CAD in which the end result was a drawing that was used as a plan in making machines. The conclusion is that CAD, by itself, does not tell you anything about HOW something is actually made. Many pieces that I create using CAD modeling are milled in wax and cast, but many others are made, at least in part, by the use of hand working techniques. Some things that can be modeled in CAD can not really be made well by casting them. Things like fine filigree for instance.

Other things that you might use CAD for are done just to see how the piece will look, (setting melee in particular patterns for instance). This then requires very involved rendering techniques, (which are actually separate from the CAD modeling end of things), to get a very realistic representation. The attached image shows a rendered model which could probably be cast in one piece, but if those little scrolls on the sides were to be done in a very crisp manner, they would need to be made of wire, inserted and soldered into place.

That ring from Tiffany was probably made from tube shapes which were then turned to the needed profile and size on a CNC lathe. This offers throughput on the order of seconds per ring with surface finishes which are good enough to go directly to polish.

 

[distracts]

I have noticed on PS that quite a few people don't seem to regard cast rings as handmade. While I don't regard CAD-designed and CAM-milled rings as handmade in the truest sense (no matter how much hand-finishing then happens, it's not fully handmade), I think if the model is made by hand, then it definitely counts as handmade.

I would consider taking a tube of metal, punching a hole in it, and polishing it up to be hand-forged (if the person did it by hand). Despite the fact that the tube came in a tube already. I mean, we consider it hand-forged if you take a piece of wire, bend it in a circle, solder it shut, THEN do other stuff to it, so if you're just doing other stuff to it, you've just taken a step out.

Mind, jewelers have some strange ideas about what is wire: a 5mm by 5mm square profile would be called wire, even though you have to whack it with a heavy hammer to get it into any shape.

My grandmother had sterling wire that is so big my gauges can't measure it - the diameter is about 1 cm. I have no clue what she did with it!

 

[aviastar]

I have noticed on PS that quite a few people don't seem to regard cast rings as handmade. While I don't regard CAD-designed and CAM-milled rings as handmade in the truest sense (no matter how much hand-finishing then happens, it's not fully handmade), I think if the model is made by hand, then it definitely counts as handmade.

I would consider taking a tube of metal, punching a hole in it, and polishing it up to be hand-forged (if the person did it by hand). Despite the fact that the tube came in a tube already. I mean, we consider it hand-forged if you take a piece of wire, bend it in a circle, solder it shut, THEN do other stuff to it, so if you're just doing other stuff to it, you've just taken a step out.

Mind, jewelers have some strange ideas about what is wire: a 5mm by 5mm square profile would be called wire, even though you have to whack it with a heavy hammer to get it into any shape.

My grandmother had sterling wire that is so big my gauges can't measure it - the diameter is about 1 cm. I have no clue what she did with it!

I agree, Distracts. Anything cast is not strictly hand-forged, but you could also say that most hand forgers use metal that they have not refined or processed, and it can become a rabbit hole.

For example, my local jeweler hand carves wax, casts in his own studio with gold he refines (recycles) and re-alloys, then finishes and sets everything. And his wife cuts most of the colored gemstones they use, too. So while not hand-forged, I, personally, feel they are handmade.

I think it's also important to remember two things here; first, all methods are going to be limited by the skill of the manufacturer and second, there are design elements that are best suited to each method. So while I have also noticed a trend here on PS that all hand forged is more desirable, I feel it is possible that depending on the design and the skill of those involved, a casting or die striking process may be better suited to the project.

Great question, Danny, thanks for asking, I am enjoying everyone's responses!

 

[Lady_Disdain]

There are plenty of artisans who prepare their own sheet, wire and tubings. It is becoming less common, specially with the rise of high tech alloy (low porosity casting gold, tarnish resistant alloys, argentium silver) which have secret formulas, exotic elements and require special equipment.

Why do I, for one, prefer to prepare my own metal? It is a mixture of cost control (manufacturing charges around here are absurd), quality control (I have received sheet with huge bubbles in them, badly mangled wire, etc), eco practices (I can reuse scrap without having it fully refined, which is a huge energy drain and uses a lot of chemicals) and because I like the control it gives me over alloys (no weird metals, full control of the colour of gold, etc). It is also easier on my inventory costs - I keep heavy gauge sheet, which I roll down as needed, instead of several different gauges around.

 

[pregcurious]

I believe that at one time Tiffany's bands were made by John C. Nordt Company, which sells bands under the Guertin Brothers name (http://www.guertinbrothers.com/). Nordt not only makes jewelry, but manufactures precious metal items for industry. Their wedding bands are made by extruding metal, which makes them very hard and dense. Cast metal, in general, is not as dense as extruded metal.