EP-420 Epoxy Primer Green or White


A superior quality, amine-cured, corrosion-inhibiting, fast-drying primer providing excellent chemical and solvent resistance. Bonds to all metal surfaces better than any other type field-applied coating. Application and curing in temperatures down to 35°F.


SURFACE PREPARATION: Surface must be clean, dry and free of rust, loose paint scale, dirt, wax, oil, silicone, and grease. Contamination may cause crawling and craters. Immediately before primer application clean metal surface with C-2200 Metl-Sol Cleaner, then wipe lightly with a clean tack rag.

PAINT PREPARATION: Pigments may hard settle after three months' storage. We recommend inverting the can every 30 days to avoid pigment compaction. Pigments hard settled in extended storage should be dislodged from the bottom with a tool, then dispersed thoroughly by agitating with a double-action paint shaker for 5 minutes minimum.

MIXING PROCEDURE: Mix exactly 1 part EP 430 catalyst with 2 parts EP-420 base component. Ratio must be accurate for best characteristics. Stir thoroughly and allow 30 minutes induction time before thinning. In high-humidity allow 1 hour induction time to avoid curing agent "bloom."

THINNING: As a starting point, for spray gun application, reduce 50% with E-500 Epoxy Reducer (2 parts catalyzed primer to 1 part reducer) (19 to 21 seconds with a #2 Zahn viscosity cup). Additional thinning may be required in warm weather to provide a wet, smooth flow-out.

CURE ACCELERATION: To shorten the cure time in cold weather, add EX-501 Epoxy Accelerator at a ratio of 1 to a maximum 2 liquid oz to 1 qt of primer reduced to spray viscosity. Stir thoroughly. One oz of EX-501 accelerator will reduce the pot life 50% at 70°F. Don't exceed 2 oz per qt.

APPLICATION PROCEDURE: Epoxy Primer may be applied with any spray equipment rated for lacquer and enamel. Apply a light, wet tack coat and follow with 2 medium coats at 10 to 15 minute intervals to avoid runs. Flooding the first coat will cause crawling and cratering on any semi-clean surfaces. Recommended dry coat thickness is .06 to 1.0 mils. Contamination from oil base coatings leaching from old pressure pot hoses or contamination from unclean or soluble plastic or plastic lined containers used for mixing or measuring will cause crawling. The spray gun head should be dismantled to remove residue from previous coatings before applying epoxy primer.

COVERAGE: One gallon of primer base component catalyzed and reduced to spray viscosity will cover approximately 1000 sq ft., one coat.

POT LIFE: The sooner epoxy primer is applied after the induction period, the better the durability. Maximum pot life is seven hours at 70°F. Discard materials when viscosity increases or becomes stringy between the fingers. Do not add reducer to extend pot life after thickening occurs.

CLEAN UP: Use E-500 Epoxy Reducer for final flush cleaning before the primer starts to polymerize in the equipment. MEK does not dissolve and flush all the epoxy resin from the equipment.

DRYING AND FULL CURE TIME: Dries to handle in 30 to 60 minutes. Full cure to develop solvent and chemical resistance is 7 days at 70°F. Lower ambient temperatures require a proportionally longer period. Full cured primer will not be lifted by adhesives, fabric coatings, enamel, or lacquer top coats.

RECOATING: To avoid possible damage and release from incompatible solvents, primer should dry 6 to 8 hours. When finishing with Poly-Tone, spray Poly-Tone into tacky primer. See page 85. Scuff-sand after 48 hours cure time when the finish is enamel. Wipe the scuffed surface with C-2210 Cleaner using new, clean rags or paper towels to thoroughly remove the sanding residue.


Guaranteed shelf life, unopened, in protected storage at room temperature is four years from date of manufacture. Avoid long-range storage above 100°F. Not affected by freezing.


Each component is sold separately, or packaged in a kit. Recommended unit ratios: 1 qt EP-420 base component, 1 pt EP-430 catalyst and 1 qt E-500 reducer.