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Alternative to vulcanizing frames

Hello I have some frames in conventional size and I want to make a
mold of a ring which is too big for the frame. Is there any
alternative for the regular frames which usually comes in standard
sizes?. somebody suggested me to use aluminum angle but I have not
found an appropriate size for the proportion of the model. Do
somebody have experimented making frames to make thicker or bigger
molds? Thanks Marco

Hi Marcos: Have you seen if you could stack two smaller frames
together? Wrap the edges with tape to hold them while you pack the
molds. Or if you are using the RTV type molds, Duct tape should
work, maybe super glue for a little extra rigidity. Good luck!

David L. Huffman

Marcos, I machined my own set of stackable frames precisely for this
reason. Therefore, find yourself a machine shop locally and have them
make a series for you. Conversely, I could help you out, but not
until the third week of January. Best Regards. Neil George

Marco, I produced a line of cast sterling cuffs years ago. Each one
weighed about 50 - 65 dwts. The “store bought” mold frame required
to hold one of these cuffs was cost prohibitive ( I was just starting

So I went to the industrial section of town-- Seattle-- and bought
short sections of square or rectangular steel “pipe”. They cut it
for me on their power hacksaw and it hardly needed any adjustment. I
used a variety ofthese frames for years. The company is called

Good luck, Andy Cooperman

Hi , In reference to vulcanizing frames… I have a cnc system and
make all my own custom frames… this is more expensive than buying a
standard frame, so you might want to check with supply companies like
The contenti Co 800-343-3364 or gesswein , Rio Grande… all of them
have an assortment of different frame thicknesses and openings.
Another alternative that is very inexpensive , but requires some
skill and labor is to buy 3/4 thick aluminium flat stock from 1 " to
2" or more wide , then cut it to length and bolt it together with 1/4
-20 standard bolts . This works quite well, but you must be able to
drill and tap ( tools for this are very inexpensive) you can also use
the same idea using steel flat stock and simply weld the frame
together… or have it welded.

Daniel Grandi
We do casting, finishing , molds and models , cnc for people
in the trade

Hi I have successfully made wood frames just screwed together with
sheet rock screws Works fine for me ! Russell

Is there any alternative for the regular frames which usually
comes in standard sizes?. 

Attn. Marco. You can use a 1" thick aluminum plate and bolt them
together to make the mold frame.

These plates are available in various width up to 12". Will depend
on the height of the mold frame you want to make.

You need to buy one long piece and cut for all four size. All four
corners are to be bolted together use two screws for each end. You
have to make it strong. I have seen rubber break and pop Aluminum
frames. I have made these for special orders.

There may be ready made frames on the market. If you have any
questions call me you have my number.

Kenneth Singh.

Marcos; This is a problem that inevitably comes up, and usually gets
solved. The best and most straightforward way that I have found is
to find some pipe of a size and shape that will let you put the ring
inside, and cut off a piece long enough to put the ring in. You have
now made a heavy walled, open ended can that the ring can fit in with
some clearance on all sides. That is a good description of a mold
frame, no We would love to have aluminum pipe, but if we can’t find
any we will use iron pipe. We don’t want galvanized pipe, but if
that’s all we have, we need to grind the zinc off. I haven’t tried
copper or brass. Now we refine the frame. We can bend the pipe frame
to roughly fit the shape of the ring so we don’t use any more mold
rubber than we need. Too much rubber makes an awkward mold to open.
Then we file the cut ends of the pipe smooth and more or less
parallel. We just want them smooth enough and parallel enough to
keep rubber from squeezing out in the vulcanizer. This isn’t high
precision work! I turned my first ones on a lathe, which was a waste
of effort. A good straight hacksaw cut and all little filing will do
quite well. Last, we polish the inside of the pipe mold. We just
need to remove the surface rust and irregularities so the rubber
doesn’t stick too tightly to the iron. The resulting frame will work
just fine. Mold rubber wants to stick to the iron much more than to
aluminum, so I’ve used mold separating powder and spray mold release
while I’m packing the rubber and it works well enough. That should
get you going.

Tom Hollis

G’day Marco. Almost every Month somebody sends me a component to cast
up and I don’t have a mould frame for it. What I usually do is cast
a larger frame in sand and machine the centre to the correct
dimensions. Most Machine Shops In your area should be able to
Machine the correct frame size for you out of a billit of aluminium.

If you can not find anyone then give me a call of line with the
dimensions and I will cast you up a frame or give you Instructions
to cast up a Frame.

Kind Regards.
Michael W Kohlleppel
Art Tech Castings Australia
@MWKohlleppel or

Marcos, go to the phone book and find the nearest Steel yard.
Supplier of metals to the construction trade. Call them and ask where
you can get square tubing in Alumminum,steel or whatever the will be
able to supply it or tell you where to get it. They will for so much
per cut. Cut it to any lengths you want and it comes in and
multitude of sizes. Art

Hi I have successfully made wood frames just screwed together with
sheet rock screws Works fine for me ! Russell 

Good idea! We sure stay trapped in the box, don’t we? Here I was
so proud of just using apiece of pipe. And wood’ll do fine for
quite a while at 300 degrees

Hi Michael The suggestion about to cast the frame is interesting, the
frame size I need is just a bit thicker than a 1 inch frame ,actually
it’s for those kind of biker rings which come in real big proportions
but since I always have customers ordering pieces in big sizes
specially now that many people are using big pendants like crosses
and dollar emblems with big chains made of silver. Would you be so
kind to explain the casting process of this frame in more detail?

I’ve decided to cast this big pieces using the lost wax process even
when they are so large in size cause I just quit with sand casting
after so many frustrating attempts Marco

Square brass and aluminum telescoping tubing are available from Small
Parts, Inc. ( ) in 12" and 36" lengths.


At first I thought you guys who have responded to my post about
vulcanizing frames had misunderstood my question and were suggesting
frames for sand casting instead of frames for vulcanizing. But now I
believe Russell was realy suggesting the frames for rubber mold
making, Now,The question is what kind of wood can withstand 350
degrees which are the recommended for castaldo silicone and
considering that I’m using a toaster oven and not a vulcanizer to
make my molds. Marco

Marco 1 1/4" thick frames are common and they are standard. What
size opening are you looking for. You need not cast this. You can
use the following method.

Depending on the depth you need take two or more mold frames with
same size openings you could stack these on top of one another. You
have to make sure that these do not move or shift and that is
accomplished by drilling two holes and put a pin through each of
these holes. ( In fact there are mold frames made of two parts that
you can buy but these are made for 1" thick only, you can stack
these together to get 2" or use one piece less and get 1 1/2")

Regular 1 1/4" mold frames come with a 2 1/2" x 3 1/2" opening.

As a last resort I would try the pipe. A 4" or 5" OD Aluminum
tubing comes with about 5/8" thick wall and strong enough side walls
to be used as a mold frame. Castaldo use to make rubber precut in
round disc for the European market.

All the best.
Kenneth Singh from New York