7 Apr
2005
7 Apr
'05
3:03 p.m.
I've done some 2-part rubber silicone resin
moulding for military
encapsulation-
pretty well the only well we could get the bubbles out was to cycle vacuum
in a bell jar and purge ..took half a dozen cycles to get a reasonable
smooth finish..
The molds are not having a problem with bubbles. The resin does tend to
trap bubbles. Partly that is because it sets up so darn fast.
you using an anginate mould? I was thinking perhaps
wax or plaster might
be more tolerance accurate... the mould is the issue - it's hard to get
the 'axle' bits without make two half moulds and filling them, unless one
goes with a one piece mold and metal pin axle.
True; the axle bits can be done by over-sizing the mold indentations for the
pins. Then they still trap air, but you just trim off the bubbles (before
things get too hardened).
I actually like the metal pin axles. They seem more robust. Making little
plastic axles is fussy work and it feels like it is propagating a design
problem from the originals.
Vince