RE: [CAD_CAM_EDM_DRO] Re: Casting clearance

>-----Original Message-----
>From: Jon Anderson [mailto:janders@...]
>Someone mentioned Carnuba wax earlier, I really don't think this by
>itself would make a good release agent....

Not at room temperature, but by applying heat, it melts completely, providing a
garanteed release action.

The silicone release that is recommended for the kit has no phase change to
release it; it must at the same time have a consistency that is hard enough to
take the casting impression, but soft enough to break and/or flow once you try
to remove the cast nut.

You might also consider using something that is soluble (e.g. shellac) as a
release/spacer, but then you have to worry about how long it will take for the
solvent to reach into the deepest crevices.

>...However, it's a pretty hard wax,
>and might do a good job of filling in imperfections.
>Maybe the best approach would be a light lapping with a brass female lap
>to remove any high spots and micro burrs, followed by a good cleaning,
>then Carnuba wax to try to fill in the micro pits.

Whether that happens depends on the shape of the pits rather than their size.
The wax will fill an arbitrarily deep pit as long as its mouth is narrow enough.
On the other hand, the wax will conform well to (i.e. *not* fill) a wide shallow
pit.
-Kevin Martin