Pouring a Mould

 Weighing the components accurately  -- + or - 0.01 gm

Weighing the components accurately  -- + or - 0.01 gm

 Pouring mixed liquid rubber into mould,  frequently through a very small hole.  Meanwhile the material is starting to cure, and getting thicker by the minute.  Pouring 1 mould is easy but 3, 4 or 5 gets tricky.

Pouring mixed liquid rubber into mould,  frequently through a very small hole.

Meanwhile the material is starting to cure, and getting thicker by the minute.

Pouring 1 mould is easy but 3, 4 or 5 gets tricky.

 Evacuating the mould to get any remaining bubbles out.  Then into a heated Pressure chamber to cure overnight.

Evacuating the mould to get any remaining bubbles out.

Then into a heated Pressure chamber to cure overnight.

 Heated pressure chamber ----  60 psi    100 to 150  degrees F  60 psi in this pressure chamber collapses any remaining bubbles in the mixed polyurethane rubber.  Then after 5 + hours in the heated air the castings are cured and bubble free.

Heated pressure chamber ----  60 psi    100 to 150  degrees F

60 psi in this pressure chamber collapses any remaining bubbles in the mixed polyurethane rubber.  Then after 5 + hours in the heated air the castings are cured and bubble free.

 Last step    Demoulding and clean up.

Last step    Demoulding and clean up.