How do you stop epoxy pigments from sinking .Metallic powders to color the epoxy are heavy by nature. If the epoxy feels saturated with pigments most of them will tend to sink at the bottom. Only 2-3% of the mass is actually required to color the epoxy.
When most pigments on the market are very heavy, we have selected our CHILL PIGMENTS to be the lowest ” MICRONS” possible to have better dispersion in our CHILL EPOXY systems. Working with pigments from different companies can be difficult. The mica powder being of different weight can eventually sink to the bottom of the epoxy. In order to avoid this phenomenon, there are different techniques. All brands of mica powder are different, with different densities and for different applications.
The interaction between pigments and epoxy can create a number of problems
First, the pot life as well as the epoxy curing time are very important. Ambient conditions including temperature, viscosity, epoxy cure rate are important factors. As you know, epoxy Part A “Resin” and Part B “Hardener” have different viscosity/density. When your epoxy begins its exothermic reaction, the epoxy will begin to gel, thicken and harden which will engage the exothermic curve, and therefore heat. As the epoxy gels, the more the viscosity will increase and the easier it will be for the pigments to remain suspended in the resin. It is for this same reason that it is useless to make swirls right after pouring the resin. Of course it’s pretty but your effects will quickly disappear in a resin that is still low in viscosity.
Mica powder once mixed with epoxy reacts in a particular way. Even though the powder remains very fine particles of mica, pigments still are heavy compared to the viscosity of the resin. Those will tend to eventually draw down. Another problem noticed by several users is the fact of putting too much pigment. It is important to put a % between 2-3% of the mass so as not to saturate the resin and create unnecessary weight. This weight along with gravity will drag more pigment down.
It is important to take into consideration when buying pigment the size of the particles of these. The particle size will have a direct impact on the suspension of the particles in the resin. Mica powder measures in microns (µm) and higher particle size means higher weight.
How do you stop epoxy pigments from sinking : DEEP CASTING
The problem with deep flows is that the system will stay liquid longer. Mica powders which will therefore have more time to flow. Including the importance of not saturating the resin. Just add a little at a time and build the color. Many users mix mica powder immediately after mixing Resin A and Hardener B and get great results. We advise to mix the resin and the hardener the recommended time, add the pigments, and mix 2-3 minutes more in order to color the resin well and avoid accumulations.