COATING WITH EPOXY RESIN

SET UP

Your standard epoxy kit will contain: 1 can epoxy, one can hardener, dispenser pumps to provide the correct mixing ratio. For application, you will need several thin foam rollers, a roller handle, a throw-away roller tray (we use foam picnic plates), and one or more inexpensive nylon or bristle brushes. Additionally, you'll need several 8 oz plastic or paper throw-away cups and several tongue depressors or paint paddles for mixing.

For personal safety, you'll want either latex or some other thin gloves, or a protective hand cream (we use SBS 46). Acetone or lacquer thinner and paper towels are used for clean up.

PROCESSING VARIABLES

The processing variables for epoxy resin are temperature and time.

• working time will depend on the ambient temperature and volume of material. This mixture generates heat when it cures, and heat makes the reaction speed up. For this reason, you want to work with small batches - 3 to 4 pumps at a time.
• cure time - this resin will set to a hard, sandable surface in 16 - 20 hours at a 70° temperature. The cooler it is, the slower the resin will cure. From our experience, the material will cure at 40°.
• mix ratio - the mixture must be used at the proper mix ratio. (Attempting to make it cure 'faster' with more hardener will only result in a non-cured mess). With one stroke each, the pumps supplied will give you the proper 3:1 ratio.

The resin cures gradually, changing from a viscous syrup to a sticky taffy, through soft cheese, hard cheese, soft rock, and eventually hard rock.

Also be aware that attempting to heat the work area after you've applied resin will result in air bubbles in the surface (as the air in the wood heats, it expands and tries to break thru the resin surface). Let the wood reach eventual working temperature before applying resin.

APPLICATION

Be sure the wood you are coating is dry, clean (no dust), unmarked (no smudges from the vacuum hose), fair and/or flat and as scratch-free as you want. If you're attempting to get a mirror-smooth finish, use a sanding board to get rid of the medium-level hills and valleys in the wood.

You'll be applying two coats to the wood - a thin seal coat and a thicker build coat.

Mix 3-4 pumps of epoxy and stir well. Pour a small quantity into the roller pan. Get the roller barely wet and apply to the wood. We usually will apply the resin across the grain, and then roll out with the grain. Use just enough to get the wood wet - you should not have any shiny areas. Use a brush to reach any areas not accessible to the roller. Also use the brush to tip off the surface - this will slightly smooth the resin and will break any trapped surface air bubbles.

Let cure overnight. The resin is cured enough if it generates powder when sanded with 80x paper (if it gums up the paper, it needs more curing.

Mix 3-4 pumps as before. Apply a thicker layer, working to achieve a uniform coating without runs. Tip off as before. Double-check that resin on vertical surfaces doesn’t sag (shows fat bottom edges).

Let cure. You're now ready to prep sand for varnish application. Using a sanding board will give you a much flatter surface than either sanding by hand or with a 6" rubber block.

ACETONE IS VOLATILE AND FLAMMABLE. DO NOT USE NEAR FIRE OR OPEN FLAME.