Re: [CAD_CAM_EDM_DRO] Flat surface creation revisted

----- Original Message -----
From: drking777 <david.king@...>

> The method of using an epoxy goo to create a flat surface appears to
> be an econimical and quick method. Can someone elaborate on this
> method further [Doug??? :)]
>
> I am curious as to a supplier(s) of the epoxy, powered metal and
> fumed silica. Also, do you have a recipe for creating the "flat
> surface soup?" What is the best method to apply the potion? What
> would one use as a release agent on the linear rail?

Marine epoxies are available from several sources. The biggest difference
in them is price. I get mine from Raka down in Florida. They also have
fumed silica and various other fillers.

Powdered metals are best purchased from Douglas and Sturgess Art supply in
California. Prices are good because artists don't have any money. I mixed
powdered steel with epoxy and filled the holes in a drill press table once.
After scraping you could hardly see where the holes had been. This mixture
scrapes nicely.

Epoxy has excellent self levelling qualities. However, if you mix powdered
metal to a pouring consistency the powder will tend to settle after it is
poured. This is ok if you get the mix just right and you plan to scrape it
anyway.

Fumed silica is a thickener used to prevent running so it also prevents self
levelling. A good mix for grouting rails is about two parts steel to one
part epoxy then enough silica to make a peanut butter consistency.

A word of caution: Cheap epoxy (and some expensive epoxy, such as West) has
diluents that cause shrinkage during cure. Even epoxies that claim to be
solvent free will often have solvents anyway. I know of one source for
completely solvent free epoxy but have never used it.

Several coats of carnuba wax make a good release agent. You will know if
you didn't use enough because the parts will not separate.

I've located moly disulfide and teflon powders and hope to try a homebrew
version of Moglice sometime soon. Cost will be about one fifth of the real
stuff.

I have a lightening storm moving this way - time to unplug the modem. I'll
try and dig up more info later if there is an interest.

Doug