If silicone rubber or caoutchouc are used for hot vulcanisation, all of the model's dimensions must be made about 5% larger to compensate for shrinkage of the rubber.
This is not necessary when using rubbers for cold vulcanisation type RTV silicone, such as the series "Ditto TM Mould compounds"by Rio Grande.
To obtain perfect waxes, it is imperative to make release cuts in the rubber along the comers of the support net.
Cross section of the rubber mould
Injection JWaxes
It is advisable to use elastic or flexible waxes, coloured blue if possible, such as "Plast-O-Wax", "Flexiplast", "Magnaject", "SRS 866 blue" or similar.
Each wax must be checked thoroughly and repaired and cleaned if necessary.
"Setting" the stones in wax
A special tool, such as V ACU-SET must be used to position "set" the stones in the wax rapidly without damaging or scratching the latter
Before positioning the stones in the wax, "grooves" must be filled with liquid or pasty wax, such as "Disclosing wax" by Kerr.
When setting delicate stones such as cubic zirconia, garnets, tourmaline, etc., it is imperative to leave an extremely small space between the stones to prevent these from breaking after the metal is cast. Diamonds, rubies and sapphires are less delicate and can be placed closer together. The space between stones must only be visible with a magnifying glass and not to the naked eye (about 0.05 mm).
"Setting stones" in the wax
ไม่มีความคิดเห็น:
แสดงความคิดเห็น