Re: [CAD_CAM_EDM_DRO] Re: Cast resin for a cnc mill design - good idea?

> I have done the searching and have a wealth of links to info and
> supliers. However, using resin seems to be such a great solution,
> that a little red flag goes up in my mind. Too easy, you know what I
> mean? I really want to be certain that my idea will work.
>
> I will go with epoxy, no doubt. What about additives, like powdered
> metal or granite? Overkill?

Not at all. There are myriad fillers used in epoxy to produce specific
results. Granite is good. I believe quartz aggregate is very good for
damping. PVC, carbon graphite, glass and polypropylene fibers have been
used. Most builders are secretive about their fillers but its still
available in university papers.

> Another concern:
> I know of a company that manufactured replicas of museum statues in a
> cast resin and powdered stone mixture. Allegedly the statues would
> begin to crumble after a few years. I am wondering now if it had to
> do with exposure to the ultraviolet light in sunlight. I'd hate to
> have a crumbling cnc mill in a few years if I forget to draw the
> shades...
>
> Tom Murray

Epoxy is very sensitive to UV and will show signs of degradation in just
weeks if left unprotected. Paint it and you will not have problems.
Commercial casters often spray the mold with polyester gelcoat before
pouring to impart a solid color. For indoor use you can probably get away
with no coating at all, unless you have sunlamps for lighting.

Doug