Making a custom Platinum Diamond engagement ring

Step 9 The finished mould

Here is the finihsed mould 24 hours later.

Encased inside is the wax model.

I use a sharp blade to cut the mould open, to remove the wax model.

The cavity left in the mould is a perfect copy of the master wax model.

To produce more wax models, liquid wax is injected into this mould. Within 30 seconds, it cools and the mould is opened to reveal a wax duplicate.

If I wanted to produce hundreds of this design, I would simply use this mould again and again. tat however is for the "high street". I make unique items for each client, so I won't re-use this mould again.

Comments

[ratdude117]

Wait, I have a question. So, this big block of rubber has your carefully carved piece of wax inside it, and you start slicing it in half with a knife? This sounds scary. Aside from experience and care, is there a technique or something to keep you from scratching or cutting the outside of your piece?

[CaseBoy]

 see the big block of rubber is a mold, so you don't really need the carved wax. 

[berky93]

I don't know about preserving the original, but considering it is a mold, as long as you cut precisely you could simply re-mold a new one out of wax, this time with the mold already sliced in two for easy access to the ring.

[Rossiroller]

 there are ways to make to mold with the slice already in it, by pouring half, then pouring the other half..... but in this case, because of the air holes, i dont see how you could cut the mold in half without having to cut the ring in half...... i guess thats why im not a jeweler!

[DavidRobertson]

 simple - lay the ring on its side

[samando]

Do you just throw away your old mould? If not , where does it go?

[aqwiz]

it's called "breaking the mold. . . e'er heard of it?

[samando]

nope, I haven't, sorry

[aqwiz]

wow, then you have missed out quite a bit culturally, . . . if someone says "they broke the mold on this (whatever)" it means that it is unique, and can't be made again (aside from mimicking the original) in other words, craftsmen regularly break their molds (and dispose of the pieces however they see fit, be it recycling them into new molds, if applicable, or throwing it away) so that the item that they made is completely unique and 1 of a kind

[samando]

right, thanks to both of you for explaining the phrase so well.

[aqwiz]

can also apply to people and non-moldable objects, as an analogy for uniqueness

[celtic_smith]

I wanted to say that your instructable was very well done! I'm a goldsmith myself and even I learned a few things. Graeme

[aglaranna]

There is a better way to do RTV molds than pouring the whole thing and then cutting it open; try this method: http://www.micromark.com/html_pages/instructions/82083i/part_mold.html That way there is no cutting at the end! I always hated the other kind of molds because you had to cut it open and it was easy to screw up, but this way I don't have that problem!

[chrisparry]

Hi You can make a two part mould and some prefer such a thing, but I find it quicker and easier to make a one part and cut it open. It is quicker, you don't have to allow for two (overnight) curing sessions of the RTV compound. In addition, the settinng up of the mould box for the second half of the mould. It is all down to what you prefer.