High failure rate in waxing

Steve, Ordinary talcum powder in drugstores contains perfumes
and possibly other ingredients that eventually attack natural
rubber. Over time they will degrade your molds. Done properly, you
should easily achieve well over 90% successful injections. To
start, install a dessicator/filter (drier/oil separator) in your
air line close to the injector - you want clean dry air. If you
don’t have one, get a good dial thermometer for the tube hole in
the injector’s cover. Next clean out your injector and replace
the wax with fresh material. Never reuse wax that drips from the
nozzle or from unsuccessful injections.

There are three variables that must be controlled in order to
get consistently predictable results. Wax temperature, injection
pressure and clamping force on the mold. These three values
should be as low as possible depending on the type of product
(filigree, heavy cross sections etc.). While most people can
adequately control the temperature and injection pressure, they
fail because we cannot accurately and repeatably control the
clamping force between our fingers.

Rio Grande and Gesswein carry a tool called “Speed Clamp” that
utilizes the air supplied to the wax injector to feed a pneumatic
cylinder that applies a controllable and repeatable pressure to
the mold. It comes with its own gauge and regulator so that the
pressure on the mold is regulated independently of the injector.
Once the proper values are found for each mold, write them on the
mold. Any one can then exactly duplicate the original parameters.
If you need further help, Liz Brehmer at Rio Grande or Elaine
Corwin at Gesswein are extremely knowledgeable and will gladly
help you.


Thanks very much for your pointers. I’ve printed them for
future reference and put it into my ever-thickening folder of
Orchid info. Someday, some rainey day, I’ll have to go thru them
all and index them by subject so I’ll have much (though certainly
not all) of the vast knowledge born of experience of which I
bennefit form on Orchid. I’ve been here for almost a year now
and I am constantly amazed and revitalized by the number of
generious people out there who volenteer their help so freely.
However, If it were not for our Doctor Aspler, none of this would
exist for our mutual bennefit. Many thanks again; Steve

Hi Ray, It was good to see you at the MJSA show in N.Y… Sorry I
didn’t have more time to talk. You mentioned the Speed Clamps
available at Gesswein, Rio, etc. I have several of them. They
work great! I’m doing alot of ticky injection and find these
clamps very helpful. You suggested a line drier for the
compressed air pressuring the wax pots. A cheaper and even better
solution (a good line drier can be expensive) is to use nitrogen
to pressure your wax pot. Not only is it completely dry, the
non-oxygen atmosphere will keep the wax “fresh”. J.A. J.A.
Henkel Co., Inc.,Moldmaking, Casting And Finishing.

Hello, Well I just started reading this thread on wax failures,
and I don’t know if this has been suggested yet… But alot of
times when wax will not fill the mold thoroughly often times it
just needs to be vented… By this I mean just take a exacto knife

Hi folks,

I have found just the opposite with wax injection, using various
injectors and even vacuum. When I have a troublesome mold that
won’t fill properly I turn DOWN the pressure. And sometimes the
temperature too. This usually does the trick.

I thought I was pretty smart until I ran into this compromise of
physics, but this is the way it works for me. Slower, lower.
And sometimes just more patience.

John g


Sounds just like my Dad! Really frustrated me how he always
figured things out so fast. He’s been gone 12 years now and
still, when confronted with difficult problems, my first impulse
is to call him! I think it’s something to do with age &


Steve, That is funny how my father can always get a mold to
shoot, as with your dad… But it drives me nuts when he turns up
the pressure… I can get most molds to shoot and fill with only 8
to 10 pounds… Whenever I can’t get one to fill sometimes I will
try to turn up the pressure and I still won’t get it to fill. I
just leave for my father… lol Marc

The cutting a vent where the wax won’t fill works, but then you
also need to powder it in that newly cut vent also. You should
use a powder made for molds also. I’ve heard people say you can
use any talcm powder but it does’nt work that way, if you use
one with perfumes or oils in it it will really cause problems
later and the same goes for mold release sprays. If you feel you
need to use the spray then only use it where you need to and
don’t over do it or you’ll end up witha goopy unusable mold.
Good luck! Matt the Catt@ C.I.A.