21ES020 Epoxy Sealer
General Description

This Surface Tolerant Epoxy is a clear rust penetrating sealer designed to wet, strengthen and seal porous rusty steel surfaces. It is recommended for areas where, due to restrictions or economics, blasting or thorough hand cleaning is not feasible. It is an excellent sealer for encapsulation of old coatings, where removal is not feasible or for aged "white rusted" zinc rich coated surfaces.

This product is for industrial, and commercial use as a protective maintenance coating for industrial plants, pulp and paper mills, textile mills, chemical processing plants, waste water plants, refineries, food processing plants, commercial buildings and marine structures. It iw ideal for coating and protection of storage tanks, piping, roof decks, water towers, structural steel machinery, plant equipment, marine vessels, offshore structures and other surfaces exposed to humidity, chemicals and corrosive environment.

ES020 is 100% solids at very low viscosity. It is designed for application at low film thickness and will not shrink upon curing. It provides excellent substrate wetting and may be top-coated with a wide variety of coatings such as alkyds, silicone alkyds, epoxy esters, epoxies, phenolics, acrylics and urethanes. ES020 offers excellent abrasion and moisture resistance. ES020 is excellent as an undercoat with various FPUWC topcoat urethanes systems to extend UV resistance, longevity and performance.


Vehicle Type Solid Based Epoxy
Solids Content ± 2% 100% by weight
100% by volume
Coverage (Theoretical) 1604 sq ft per gallon at 1 mil DFT
1069 sq ft per gallon at 1.5 mil DFT
Coverage (Estimated) 1283 sq ft per gallon at 1.0 mil DFT (20% loss factor)
855 sq ft per gallon at 1.5 mil DFT (20% loss factor)
Number of Coats Normally one coat 1.0 to 2.0 mils DFT, 2 coats if required (concrete porosity is an important factor in coverage and thickness)
Application Method Conventional spray, brush for small areas if necessary.
Thinner Not recommended.
Clean up solvent No. 7535, MEK or MIBK
Shelf Life at 75° F One Year from Date of Manufacture, unmixed, stored at 40 - 100°F (Re-inspect after 12 months)
(Drying time at 75 ° F)
2 hours to touch
8 hours to handle
24 days to re coat
Induction Time 15-30 minutes @ 70� F (See "Mixing" below)
Flash Point (Seta Flash) >200°F for Component A
>200°F (12°C) for Component B
Color, Gloss Clear (Gloss and Semi-gloss)
Pot Life 4 hours at 70°F (21°C),
Mixing Ratio 2 to 1 by volume
VOC Content 0 lbs/gal; (0 grams/liter), calculated
Shipping Information 27 lbs per 3 gallon unit (2 gallon part A, 1 gallon part B)
Freight PAINT, No label required.

IconSurface Preparation

Good surface preparation is essential to a successful coating system. 21ES020 Surface Tolerant Epoxy is formulated for application to rusty ferrous metal surfaces. The performance life of the system will, in part, depend on the degree of loose rust, rust scale and unsecured old paint removal. In addition, any oil, grease, or chemical contamination must be removed. It is recommended that Prep No. 101 cleaner be applied to any oil, grease, or old paint. A high pressure sweet water wash should then be applied to remove the contaminants as well as dislodge the loose rust, rust scale, and other contaminants. Extra heavy rust scale may require hand or mechanical removal. When surface has thoroughly dried, 21ES020 may be applied. Allow overnight curing (16 hours), and then topcoat with 21CC EP150 and 21CCEP152, or 21CCFE316.


Apply in good weather when air and surface temperature are above 50�F and surface temperature is at least 5° F above the dew point. For optimum application properties, material should be between 70° to 100°F prior to mixing and application. Maintain unmixed material in closed containers in protected storage at 40° to 100° F.

Previously Finished Surfaces:

Repair all damaged areas. Remove gloss from previous paint by sanding or "brush blasting" (SSPC-SP7). Remove rust, corrosion products, heavy chalk and loose or peeling paint by "hand or power tool cleaning" (SSPC-SP2) Spot prime with 21ES020 any bare areas as in new work. If there are no signs, coating work can proceed.


Surface must be clean, dry, properly cured and free from all contaminants and laitance. Concrete surface must be free from loose or hollow areas. Fill cracks, fissures holes with a non- shrink acrylic filler. Remove all dust before coating. Apply by brush one coat of 21ES020 Surface tolerant epoxy sealer over any crevices, bug holes or spalleds. Apply 21ES020 over entire area to a minimum of 1.50 mils DFT (50 microns), approximately 5-6 mils wet. Allow to dry at least 16 hours. Application on very porous surfaces may require multiple coats to assure that the surface is completely sealed. Apply a full coat of succeeding coat intermediate and FPUWC series Topcoat, over entire area.


This is a two component coating supplied in two containers as a unit. Always mix a complete unit in the proportions supplied. Use a power agitator for each component. Allow to stand for 15 minutes and remix before application. Usable pot life depends on the temperature of the material.



Icon Application

Apply by conventional air spray, brush or roller. Airless spray is not recommended. To minimize overspray, use low air pressure 5 to 200 psi and low pot pressure 5 to 20 psi. Do not apply heavy coats. NOTE: During lunch, breaks or any period of work stoppage, material should be removed from hoses and equipment. Release pressure from equipment and flush hoses and equipment with No. 7537 Thinner, 21AL50 Blended Thinner, MEK, MIBK. Do not re-pressurize equipment until ready to resume work.

Clean all equipment immediately after use with #7537 Thinner, MEK, MIBK. Completely flush all spray equipment with this solvent. Occasional flushing of spray equipment during the course of the working day helps prevent buildup and possible clogging.


Safe storage, handling and use dictate that adequate health and safety precautions e observed with this product and any recommended thinners. User is specifically directed to consult the current Material Safety Data Sheet for this product as well as precautions contained on product labeling.

Notice: The technical data contained herein are true and accurate to the best of our knowledge. All products are offered and subject to the manufacturer standard conditions of sale. Published technical data and instructions are subject to change without prior notice.


Additional Information

For additional information contact your Distributor or :
21st Century Coatings, Inc.
4701 Willard Ave., #426
Chevy Chase, MD 20815
Tel: (301) 654-0099 Cell: (301) 873-5230
Email: johnshammas@gmail.com