Degassing the *** pulls out all the air bubbles mixed in when stirring the
catalyst into the ***. For this, you will need a vessel equal to at least
twice the volume of the *** to be degassed.
Afterwards, simply pour the *** carefully around the sides of the master,
between master and the mold box, to avoid trapping air against the master.
> Degassing the *** pulls out all the air bubbles mixed in when stirring
> catalyst into the ***. For this, you will need a vessel equal to at
> twice the volume of the *** to be degassed.
> Afterwards, simply pour the *** carefully around the sides of the
> between master and the mold box, to avoid trapping air against the master.
> >I'm in the process of creating several molds that have to be
> >transparent. Having decided on a *** compound from Smooth-On that
> >meets the necessary criteria there is one other hurdle to overcome --
> >tiny air bubbles that seem to form while the mold material is curing.
> >These bubbles effectively render portions of the mold opaque after
> >curing. Posts seem to suggest that most of these bubbles are created
> >during the mixing process but this doesn't seem to be the case here
> >unless they were microscopic after pouring and merely got larger
> >during curing. A Smooth-On rep suggested that it may have been too
> >much release agent, too much moisture in the master etc., etc., etc..
> >Whatever, I am investigating taking the vacuum chamber approach in
> >getting rid of these bubbles since it would seem that the possible
> >sources are many. Would placing the poured setup in a vacuum chamber
> >(20 - 25") for the duration of the material's pot life (30 minutes)
> >be worth a try? I don't see any advantage in placing the mixed
> >material in a vacuum chamber before pouring if the entire poured setup
> >can fit in the chamber. Perhaps I'm missing something here.