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Vulcanizing pewter models


#1

Dear wonderful jewelers with bountiful stock wisdom, Can a piece made
out of pewter or tin withstand the heat and pressure of a vulcanized
molding process?

sincerely,
Daniel


#2
Dear wonderful jewelers with bountiful stock wisdom, Can a piece
made out of pewter or tin  withstand the heat and pressure of a
vulcanized molding process? ? 

The answer to this has many interesting quirks as you will see by my
answer. Yes, a mold can be made from a pewter " model".

If the model is contructed of pewter ( which should be Pure tin) you
will not have a problem. You can have a problem with some of the
solders available that are used to solder a tin model together. You
must make sure that the solder selected will match up with the
molding temperature of the rubber you are using.

There are many items that you may buy in a store that may be stamped
"pewter" but that does not mean that it is pure tin. There is a large
variety of metals that are tin based called “white metal”.

An example would be" 88" metal which is only 88% tin … this will
melt in a vulcanizer at between 300 to 350F … if the metal is "92"
or “95” metal , it will not melt at vulcanizing temperatures .

The worst situation is that you have an item that was given to you
or that you bought and you assume that it is of a high tin/pewter
concentration… you proceed to make a standard mold and the model
melts down as it may be made of a tin /lead alloy that melts at low
temp.

My suggestion is that if you are not positive of the metal
composition, then Err on the safe side and make an RTV type of mold
or a low temperature mold.

If you are making the model yourself, A large selection of tin
/pewter sheet ,wire and solder is available from Contenti supply
company 800-343-3364 Steve, who is a salesperson at contenti is a
good person to ask what solders would work best for your potential
applications.

Hope this is helpful.

Daniel Grandi

Racecar Jewelry Co. Inc
tel: 401-461-7804
We do casting and finishing in a wide assortment of metals for people
in the trade


#3

Daniel:

Yes, pewter can withstand the vulcanizing process. I do it all of
the time. Of course if the model is not flat the pressure can distort
it.

Ken Gastineau
Gastineau Studio
Berea, Kentucky


#4
    Can a piece made out of pewter or tin  withstand the heat and
pressure of a vulcanized molding process? 

Why not just use an RTV mold rubber and not worry about the heat and
pressure of the heat vulcanized materials???

John Dach


#5

Daniel,

You can try the new LTV (low-temp vulcanizing) compound from
castaldo. It vulcanizes between 160 and 190 F, which means you can
even vulcanize many types of wax models. Pewter would be a snap!

Consider asking them for a sample - they were giving samples away at
MJSA and might be amenable to sending you one to try.

Enjoy!

Karen Goeller
@Karen_Goeller


#6

Daniel,

I vulcanize pewter masters in the Gold Label or Pink Label rubber
all the time with no problems.

I learned the process the hard way (thru experimentation) after
someone gave me a master made of Sculpey clay, and it stuck like
crazy in the RTV mold. I thought the master was ruined, but then I
had the idea to carefully pry it free from the RTV, glue it back
together, and sandcast it in pewter. Then, I re-detailed the pewter
master, and held my breath while it went through the vulcanization
process. It worked beautifully.

Hope this helps!

Lyn Punkari
Darkridge Jewels
www.darkridgejewels.com