Epoxy Resin & Beyond

The instructions that follow apply to most two-part epoxies including all those found in the Rio Grande catalogue. The brand I use most is Devcon 2-part epoxy, which comes in two versions. One sets in about 5 minutes and the other in about 20 minutes. They may be used interchangeably in most cases as long as the time element is kept in mind. In most instances it is advisable to use the 20-minute as it affords you more time to work however, there may be situations when a quick set is necessary.

The instructions that follow are for using epoxy as a design element. It should be noted that it is also very useful strictly as an adhesive and will work effectively on most materials. Both types of Devcon are available in 2 oz. syringe applicators and 4 ½ oz. bottles.

As with all catalytic materials, there is setting time and curing a time. With epoxies, setting is the time it takes for the epoxy to harden and curing is the time it takes for the epoxy to gain its full strength and become dry to the touch. For both versions the curing time is about 24 hours.

MIXING

Working on wax paper aids in cleanup and also allows you to slip other paper beneath to use a background for mixing
Squeeze out equal amounts of part A and part B onto the wax paper (one is the glue and the other is the hardener). If you're not sure of the amounts, trace a coin twice on white paper and slip beneath the wax paper and fill the circles with A and B. The white paper also acts as a good background for mixing colors. Mix well, stirring from the outside in, trying to minimize the bubbles by not "whipping up" the epoxy. Flat toothpicks are great for small amounts and palette knives work well for large amounts
Adding pigments can be done at the beginning or any time during the mixing process (pigmenting will be discussed later)
Small amounts of epoxy can be applied with a toothpick or a drinking straw cut at an angle while larger quantities may be applied with a palette knife, Popsicle stick, tongue depressor, or spatula.

COLORING

Just about anything can be added to the epoxy to color it. Dry pigments, acrylic paints, metallic powders, gold leaf, and eye shadow are just a few
The epoxy is easily tinted and pigment should be added a little at a time and only until you get the opacity you want. Too much color (especially acrylic paint) will interrupt the curing process and leave you with a goopy mess that will never really cure. One of the unique features of using epoxy is that you are able to mix very translucent colors and layer them with and without inclusions to achieve amazing depth in a relatively shallow space
Mixed colors may also be placed next to one another without them bleeding into each other

USES

Casting - Epoxy cast beautifully into silicone molds and no release agent is necessary. This can be useful to test molds before you use PMC. Almost anything else can be used for a mold as long as there are no undercuts and a proper release agent is used
Filling a form - Epoxy can be placed in any form with a wall to keep it from flowing out. Inclusions may be placed in the form before or after the epoxy is added, depending on your desired result.
Covering an item - Epoxy can be "buttered" onto a surface however, gravity will tend to pull it down the sides of a curved form. Masking tape can be used as a fence to allow a build up of epoxy on a surface and removed after setting
Forming billets and discs - Items such as neoprene or rubber washers, rubber bands, Plexiglas rings, etc. can be placed on the sticky side of masking tape and filled with epoxy. After curing the tape is peeled off and the ring removed to yield a solid epoxy form that can be treated as a solid piece of plastic

FINISHING

Epoxy can be filed, drilled, ground and cut however, you should wear a particulate mask while doing so
It can be sanded safely without a mask as long as silicon carbide sandpaper (also called Wet of Dry) is used with water to keep dust from forming. Depending on how smooth the piece is to begin with you can start with #320 grit and proceed to #600 grit to achieve a surface ready for polishing. A hint that can be used when sanding any surface is that after sanding with the #600 paper, turn the sandpaper over on the back paper side and polish with the back. On most surfaces it will yield a beautiful soft shine and can be used as a final finish
You can also proceed to a buffing wheel if desired as long as you use a plain muslin wheel and keep the speed low by using a small (3") buff with no compound. Wax will also give a rich luster and shoe polish works well as does Renaissance Wax and furniture polish.

Play Well,
Robert