Help!

Hi,

I’m in a pickle. I need to learn to make rubber molds. I know
nothing about this. I’ve looked at the catalogs and have been
in a daze at the myriad of molding compounds, injectors, and
waxes.

I have a budget of under $700 and need to keep it under that
figure. It would not need to be high volume, and doesn’t need
to have bells and whistles, nor be extremely fast. It needs to
be durable and long lasting. Some of the questions I have are:

  1. To use vulcanized or bench cure molding compound. What are
    the advantages and disadvantages of each. Ease of workability,
    durability,etc.

  2. Wax injectors. What brands, what do I look for. It doesn’t
    need to be real fast. This is for limited production but I
    would like to buy only 1 that I can grow with.

  3. Wax. What do I look for. I suppose that if you use only
    one wax you get one that does everything equally mediocre.

  4. Who has the best prices and selection.

This may be a tall order, I don’t know, but if anyone can solve
my dilemma it is the folks on Orchid.

Thanks in advance. I know that you won’t let me down.

Warmest Regards to All,

Skip
Skip Meister
NRA Endowment and
Instructor
@Skip_Meister
08/29/9720:01:04

Skip,

Tall order,but this might help some:

1.start with the room temperature vulcanizing rubbers I suggest
Silastic RTV from Dow Corning The E and L are my choices. One
is stiffer for flat or large less intricate molds the other is
soft and more flexible for small and intricate pieces. I use
Ferris mold frames that they sell for there oven curing mold
compound. They are of good sizes and shapes and have injection
nozzles forms already attached. You save the cost of a vulcanizer
till later. If you decide on a vulcanizer try the red silicon
vulcanizing rubber from Contattie? spelling? (I’ll look it up and
post it later under vulcanizing rubber) it cost about a dollar a
pound over Costalto Gold label but the results are worth it. I
get waxes out that are so polished they have even come out of
the casting with a relative polished finish!!

  1. Wax injector is a wax injector. I use a 4 qt for size any
    brand name will probably do. I use a small airbrush compressor
    cost about $85.00 to save money on a large compressor.You only
    need 15 or 20 lbs of pressure on the worst molds.

  2. I use plasti-Wax from Gesswein I found it versitale for most
    sizes and about the best around for working after injection for
    changing a model and clean up.

  3. Who has the best prices? You let me know I hate to shop!

Luck Frank

I like the RTV materials. You don’t have to spend a few or more
hundred dollars on the vulcanizer either. There are many
different rubber materials, some are harder, softer, fast to go
off, long/short pot life and storage life, some need stirring
before using some don’t and most all RTV’s do not have the
shrinkage problems of most of the vulcanized rubbers. I really
like polysulfide but a disadvantage is “cold creap” so you must
store the molds with a wax in place (no big deal really and in
fact, it is a good idea to do this with all rubber molds). Polys
have great shelf life, can be mixed to go off fast (20 minutes)
of slow (4 hours), can be thickened if needed and bubble release
from the master is very good. You don’t need a vulcanizer for
these materials but a vacuum unit really makes any RTV mold
bubble free and is really a necessity (you can use it to vacuum
your investment too and get better castings).

  1. Wax injectors. What brands, what do I look for. It doesn’t
    need to be real fast. This is for limited production but I
    would like to buy only 1 that I can grow with.

There are hand pump units for a couple of $100 but if you are
planning on “growing” you might be better off spending the money
on a pressure pot (more $100’s but again, in my opinion, well
worth it.

  1. Wax. What do I look for. I suppose that if you use only
    one wax you get one that does everything equally mediocre.

There are a zillion diffefent waxes and each has certain
characteristics. Try contacting Kindt Collins and see what they
recommend and see if they can send you some samples of the
recommended waxes. Also any jewelry supplier will have numerous
types. Try them and find the one, 2 or 3 that work for you. We
inject with Serria Red. For our operation it is the best. We
have tried a couple of want to be Serria Reds and they were not
anything like the real thing but most every wax worker will have
their own idea of what is best.

  1. Who has the best prices and selection.

Shop until you dorp!!! I like the mfgrs as a source as if I
need tech help, they are more abole to give me help than most any
wholesaler telephone person.

good luck

John and Cynthia/MidLife Crisis Enterprises
Maiden Metals/C. T. Designs/ Bloomin’ Wax Works. etc. No one is
guaranteed happiness. Life just

PO BX 44, Philo, Ca 95466
gives each person time and space. It is
Ph 707-895-2635 FAX 707-895-9332 up to us to
fill it with joy.

Frank

 I use plasti-Wax from Gesswein I found it versitale for most
sizes and about the best around for working after injection
for changing a model and clean up. 

What type of plasti-Wax have you tried? Perhaps even the color
would help. I have been experimenting with some of the waxes from
Gesswein but have not tried their plasti ones. I would like one
that is flexible and capable of fine detail for small objects
(rings) up to very large (massive men’s bracelets). Any
suggestions. Thanks, Charlene @Chardens

Skip:

I’m in a similar situation to yours. Depends some on how many
molds you’re going to make and what you’re going to use them for.
I think vulcanized molds will pull more waxes before going bad.
If you vulcanize you can do it in your oven or a toaster oven,
to about 300-305F for most rubbers. You will need “C” clamps to
take the place of the vulcanizer press, and you will need some
potholders to take the mold frames out of the oven when you
tighten them. You will need at least one single mold frame and
some aluminum plates, these are cheap enough from the catalogs or
from some used equipment dealer or estate sale, etc… Get a Rio
catalog and look at the descriptions of the various waxes and
choose one to go with your needs. Bovin’s book on casting has
the best section I’ve seen on mold cutting. You need a clamp
and a chain and board to hold it, but you can build these if you
like. Use sharp new blades to cut. As far as the wax injector,
there are hand pump injectors pretty cheap, but a compressor
injector will be better to grow into and you can get a 1 qt from
Swest for 240, but show price this year at the shows has been
$199. If you have no compressor, you can use an air tank you
can get a Wal-mart for about $22. If you can find an empty freon
tank (not propane! different fittings) you can get a kit to
convert it to compressed air for about $10.

that’s about all the tips I’ve got right now. hope this helps.

Charlene,

I use the blue Plasti_Wax have had good luck with small detail
pieces and rings including large ones. I have not used this wax
for injecting large pieces like belt buckles and mens bracelets
these heavy items might be better wuth a wax designed for them.

Frank