5.8 Pre-heating
Once the wax has been eliminated, heat the mould to the final temperature for metal casting
(1000–1050 °C). The heating rate should not exceed 8 °C/min. The final temperature should be
held for 60 minutes (longer if a larger number of muffles is used – add 10 minutes per muffle).
Muffles can also be pre-heated overnight, under program control.
5.9 Casting
Follow the instructions of the alloy manufacturer and the instructions for your casting device.
5.10 Divesting
Allow the flask to cool to room temperature after casting (for at least 30 minutes).
Caution: After pre-heating, Optivest SR will lose its low-dust properties! We recommend rinsing
the muffle approximately 15 minutes before divesting to reduce the amount of dust released.
Never quench the muffle in cold water. Doing so will damage the metal alloy. Cleave it repeatedly
with a pair of plaster pliers or a divesting chisel and remove from casting. The framework can then
be sandblasted with a suitable abrasive (150-250 µm).
6
Expansion control
Table 1: Mixing
Mixing ratio (powder : liquid)
Mixing time (under vacuum)
Multivac compact
We have summarized the most important information for you in a table. We would like to emphasize
that these are only recommendations developed under controlled laboratory conditions. Variations in
temperature ranges, modeling materials, procedures, muffle systems, pre-heating ovens, casting units,
and many other factors may affect the results. If the results you achieve are unsatisfactory, consult
your technical adviser, who will be happy to assist you.
GA_Optivest SR_50571703d_0415.indd 19
100 g : 15 ml
30 – 60 s
Program #1 (Deguvest SR)
19
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