Tinting epoxies

G’day; I have found that many of the things often used for colouring
epoxy and other cements often retard setting time, and interfere with
final hardness and strength. So I discovered that the best thing to
use with glues for various purposes is finely ground chalk crayon.
Buy good quality chalks (NOT the wax type) from an artist supply shop;
you don’t have to buy a packet of colours you will never use; they are
often sold singly, so you can choose your colours. I break off a
small piece, grind it well with a small pestle and mortar; you can
get these quite cheaply in shops that sell ‘organic’ foods. You can
mix your colours and add to the glue to match whatever you want, but
when you buy them, do include a stick of white and another of black to
lighten or darken a shade. As well as jewellery, I do a good deal of
wood turning and find that a piece of wood with a very beautiful grain
usually has some flaw which spoils it; a missing knot, shake, borer
hole, etc. I even apply the matching epoxy with a hypodermic syringe
when needed, using a ‘large’ diameter blunted needle. OK, so when the
job is re-turned, waxed and finished, the discerning eye can pick the
fault, but it is then quite acceptable. In jewellery and especially
inlaid stone work, the flaws are more difficult to see. Cheers, (and
chalk this one up) –

John Burgess; @John_Burgess2 of Mapua Nelson NZ

I’ve also been quite pleased with using painting pigments- just the
coloring agents used to color paint, pastels, colored pencils, or
what have you. The minutest imaginable amount gives rich and pure
color! One does need to be careful with blending shades and
sometimes
with opacity vs. translucence, since the pigments vary in this. I
have an assortment that allows me to make almost any color. It was
expensive getting the assortment, though, since some of the pigments
are pricey.

-Amanda Fisher

John-- I am interested in your suggestion of chalk pigments to color
epoxy. I have only used enamel powders, which are expensive and
sometimes show as tiny dots, when not in large quantity. My concern
is that other powders may fade or change color over time. Have you
done this long enough to be sure that doesn’t happen? Has anyone else
used different powders/pigments that may or may not be stable? A
student of mine uses spices to do “cold enamel” inlay, and I worry
that they will lose their color. For some reason, I resist buying
Colores and the like. Any feedback would be appreciated.

–Noel

Noel, I have used powdered pigments used in the furniture finishing
and refinishing business with success. These powders are ground
extremely fine and are available in a vast array of colors. How is
this for fancy wording? Check with you local refinisher or furniture
repairman. Look for Mowhawk or Star products.

Please let me know how things work out. Bill

Noel-

The dry painters’ pigments that I use have lightfastness ratings, and
it’s easy to choose only those with the best rating. Most of the
pigments are quite lightfast, the exceptions being florescents for
the most part. I, too, haven’t wanted to use spices- I know they fade
in the jars if I leave them out in glass, so expect they’ll fade in
resin, too! Many modern artists in different medai don’t seem to be
concerned about archival quality, though, I’ve noticed.

Some of the pigments, while very finely ground, do clump a bit-
with those colors one can get spots if one isn’t careful to break up
or avoid the lumps.

-Amanda Fisher

Hi Gang,

   I am interested in your suggestion of chalk pigments to color
epoxy. 

If you’re using epoxy in the process of inlay or channel setting,
another thing that you can use to color the epoxy is stone dust from
the stone(s) being inlayed or set. This requires you to have some of
the rough the stone was cut from or an extra stone or 2. There’s no
doubt about the color, the question is the amount to add & that
varies, so you’re on your own.

To generate the ‘dust’ use a diamond cut off blade in a flex shaft to
grind the dust from the stone. Do the grinding dry, to save having to
dry & pulverize the sludge. By placing the stone & cut off blade in a
suitably sized plastic container, the dust will be contained & can
easily transferred to a baggy or to the epoxy mixing bowl.

Dave