Anti Shrink hole Paste To obtain completely dense castings with the
Lost Wax Method, not only is a gas free and micro crystallizing
alloy necessary, but permanent pressure of molten metal from the
sprue to the casting required. With this newly developed Anti
Shrink hole Paste it is now possible to control differences of
temperature during casting where the premature hardening of the
sprue can be hindered. Through the warmth conduction of the sprue,
a temperature spread occurs between the casting and the main tree
exactly at the critical temperature point between the molten and
solid state of the alloying metal. This spread creates the effect
of dense crystallization in the casting even though sprue´s
are thin and the casting is composed of thick and thin parts,
normally tending towards shrink holes.
Advantages Shrink hole free castings with solid objects.
Less work with thinner sprue´s as well economizing on metal.
Anti Shrink hole Paste is simple to use. After
the tree is assembled, a little Anti Shrink hole Paste should
be added to the points where the sprue is to remain longer molten,
the Anti Shrink hole Paste should be liquid enough that it adheres
to the wax surface without blistering (if the Anti Shrink hole
Paste is too dry, some thinner should be added in the tin and
stirred thoroughly before applying). The wax tree should dry for
30 min before covering with investment and burning out. Oven temperatures
over 750° Centigrade for gypsum bound, and 850 ° Centigrade
for phosphate bound investment should be avoided in the interest
of investment quality also. As the cast molten metal comes into
contact with the Anti Shrink hole Paste, a chemical reaction takes
place, heating the contact points for approx. 1 min., the sprue´s
sink in and the contact points show shrink holes thus allowing
the cast object to become dense. The Anti Shrink hole Paste is
in its dry form a silvery red color, should it become brittle
and intensive red after ca-sting , this denotes inadequate drying
out after investing. With correct drying out it should be hard
and black after casting.
Smelting Alloys brilliant castings
To replace alloys with a high zinc content (0.5-2%),
we have developed an alloy additive that increases both the ductility
and malleability of the metal.
With the alloy AC 9.105,
we have an additive that
1. Releases surface tension thereby allowing a
sharper more detailed result with just 0.2 - 0.3% additive.
2. Through the micro crystallizing construction of the alloys
the malleability of the metal is increased.
3. By reducing metal oxides during smelting, dryness and micro
porosity is eliminated. The residual dross (waste) sits as skin
on the molten surface.
4. With correct usage and temperature of CASTIN, the contact points
between metal and investment give not only a smooth oxide free
surface but also a high metallic shine.
Poisonous cleaning baths can be eliminated. We recommend that
a maximum of 0.3% is added to the molten alloy 1-10 minutes before
casting, giving enough time for the cleaning process to take place.
Analysis of alloy conditions will be practiced during the seminar.
Porous casting are the result of melting alloys
under less than optimum conditions. Now there is a new chemical
that flushes the gases out of the molten metal. With smaller amounts
(0-5 kg) the result is obtained by just sprinkling the powder
onto the metal and then covering the crucible for 1 - 2 min. By
larger amounts the procedure should be repeated, or with the aid
of a graphite stirring rod to submerge flux to the bottom of the
molten mass. The effect is so thorough, that it flushes not only
gasses but the Zinc and AC alloys too, these should be re-added
after the cleaning process. With the regular usage of degassing
flux, Zinc and AC, not only the castings will be improved but
the returning of sprue´s etc. to the refiners is no longer
necessary. 4 Analysis of alloy conditions will be practiced during
Transparent Blue - Hard is delivered as a two part liquid Room
Temperature Vulcanizing compound. After hardening, it remains
elastic with a high durability and offers NO SHRINKAGE. It copies
surfaces and forms perfectly, even details that are only discovered
under the microscope are reproduced. For more than 10 years this
type of compound has been chosen for highest quality precision
casting, Both compounds, due to the transparency are easier to
cut open than the conventional rubber molds. Errors in pulling
the wax can be discovered immediately, when glass instead of metal
plates are used for holding the form.
For mixing, a is necessary, obtainable in four different sizes,
Nr. Ø H
1 65 mm 54 mm
2 86 mm 72 mm
3 116 mm 100 mm
4 128 mm 140 mm
comes complete with filter and adapter. The mixed and vacuumed
mass is purred over the jewelry piece and with the help of vacuum
bell jar, vacuumed for a second time.
Offered in sizes 6 x 6 mm & 3.5mm high, with
an additional insert smaller forms can be made 5 x 5 mm &
1.5mm high. For stabilizing the model in the Form Box, a special
sticky wax and pre-formed wax sprue´s (right).
To make a rubber mold the model should be first thoroughly cleaned.
Should the model have already been copied by the usual vulcanized
mold rubber technique , the surface must be cleaned of the sulfur
compound and amino acids. The simplest way is to anneal, pickle
and then dipped in a warm sulfuric acid mix, (scratched or scraped
with a brass brush to get all nooks and crevices clean).Waxes,
Insects, Plants, Metal, lacquer objects etc., can all be used
as models. Sticky wax is melted onto an easy to clean point of
the model with a hot wax knife or a soldering iron.
On this point, the point of the ready formed sprue is melted just
enough to bind the parts together, after cooling, the connection
point is hard and strong.
The soldering iron is dipped into the sticky wax again, and a
little wax is melted onto the flat side of the sprue in the middle,
the still warm sprue and model is pressed onto the inner wall
of the mold box. The model should be positioned with a minimum
of 2 mm under and above, and a 4 mm border on all sides.
For larger models the corresponding size of box should be used.
The sticky wax cannot break, but can deform under the weight of
heavier pieces. A small piece of silicone from a previous time
should be placed under the model to support it, when the silicone
support is not too old and well cleaned it will bind together
with the newly mixed material After the form has been prepared,
the rubbercomponents should be weighed up, to fill a small box,
110 grams of ground mass, for smaller pieces less material.
The empty vacuum beaker is placed on a trainable scale and turned
to zero, the necessary amount of milky transparent ground mass
is weighed up and 9% from this amount of the dark blue hardener
is added. Exactness is not important w hile best results are obtained
even with differences between 7 and 13% hardener.
Now the cover should placed on the beaker with the tube and filter
attached to a vacuum pump, (97% vacuum should be reached ) it
should be stirred slowly for approx. 3 minu tes under running
vacuum. One turn per 1 - 2 seconds is optimal.
Look also onto our new developed Injekion pump
were you can press out first time, the mixed components without
vacuumpump and air bubbles.