7 Apr
2005
7 Apr
'05
2:41 p.m.
From: "vrs" <vrs at msn.com> wrote
To: "Heinz Wolter"
Subject: Re: Must-have PDP-11 ... GOLD PLATING AND SWITCH HANDLES
No, but the strength of the poured ones is adequate,
once they have cured.
(When they first come out of the molds, they are still too flexible.)
The silicone rubber molds give a pretty good result. The hard problems
are
getting the color right and the air bubbles out.
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..
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.