casting mold life span?

As a consumer, I've been told that a certain jeweler has been continually using a 30 year old mold to cast gold jewelry.

I thought those molds wore out after so many pours, being made from rubber. So you can only shoot hot liquid wax in there so many times, then you have to make a new mold.

Is this so?

Reply to
TRafferty
Loading thread data ...

Have you considered that it might not be a rubber master? A split ceramic or plaster master should last a really long time if it only saw hot wax.

Reply to
Jim Levie

A money making master mold might be made in carbide or SS or other tough material. Making a temp mold from it would not use up the master.

There are often master molds to master molds to continue a long line if poorer material is used. So if the sub-master can last for 4 years then adding a level higher might be 40 years or 16 or ...

Martin

Reply to
Martin H. Eastburn

It could hinge on the material of choice from which the mold was made. I made some silicone rubber end caps for some heat cables for roof drains years ago. The rubber came from a friend that casts jewelry, which he uses to make his molds. The end caps are exposed to sunlight and have held up for years with no signs of hardening or cracking. In my opinion, yes, it's possible for the molds to last that long. Depends on the frequency of use and the care they receive in being handled. The temperature of the wax isn't nearly as high as the vulcanizing temperature, so that may not play much of a role in how long it lasts.

Harold

Reply to
Harold & Susan Vordos

It is a jeweler out in LasVegas that is trying to sell his molds for $2.25 million

formatting link

Reply to
TRafferty

It looks like rubber to me but you're not buying it as a mold. It's a collectors item for one and he seems to be talking about the rights to produce Elvis glasses of the same pattern to sell. Karl

Reply to
Karl Vorwerk

I understand about the "rights" but I was wondering if the mold still be usable after 30 years.

Is it my understanding in a case like this, that the 'original' mold is used again, and again for a wax piece. Then the wax piece is used to make a mold to cast the finished gold piece in? This way the 'original' mold can be used virually forever?

Reply to
TRafferty

That is pretty much the process.

However, forever is a pretty strong term. The molds are made from vulcanized latex rubber, and are subject to some decay. UV breaks them down, they can tear or get gooey, they can get stiff and break the wax before releasing it.

I have some that I must have got the time and temp just right on the vulcanizer and they are still in excellent shape 25 years later. Some are as stiff as a shoeheel.

The patterns for "EP's" glasses are pretty much flat and condition of the mold is much less critical.

Paul K. Dickman

Reply to
Paul K. Dickman

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.