Mobar W Epoxy Mastic Primer General Description

Mobar W Epoxy Mastic Primer is a two component, high-performance epoxy coating that which offers high-build protection often in a one coat system. Many applications require a minimum of surface preparation. It is designed for application to properly prepared or sandblasted concrete surfaces and is suitable for interior or exterior surfaces. Uses include industrial and commercial application as a protective maintenance coating on storage tanks, piping, roofs, roof decks, water towers, structural steel machinery, plant equipment, marine vessels, offshore structures and other surfaces exposed to humidity, chemicals and corrosive environment

MOBAR W offers excellent resistance to fresh and salt water, detergents, many chemicals as well as good resistance to fumes and spillage of most organic solvents, acids and alkalies. It exhibits flexibility with abrasion and moisture resistance, high solids, low VOC and is excellent for use in areas where sandblasting is undesirable or impractical but high performance is required. It may be used over old coating systems to upgrade the performance. MOBAR W is excellent as an undercoat with various FPUWC topcoat urethanes to extend UV resistance, longevity and performance.


Vehicle Type Amine Adduct / Epoxy
Solids Content ± 2% 90% by weight
81% by volume
Coverage (Theoretical) 1299 sq ft per gallon 1.0 mil DFT
Coverage (Estimated) 909 sq ft per gallon 1.0 mil DFT (30% Loss Factor)
Number of Coats One (4-6 mils DFT) normally, two if required.
Application Method Conventional or Airless Spray, may be brushed or rolled if desired.
Thinner No. 7537 for spraying
No. 7535 for brushing
Clean up solvent No. 7537, No. 7535, MEK or MIBK
Shelf Life at 75° F One Year from Date of Manufacture (unmixed)
(Drying time at 75 ° F)
3 hours to touch
8 hours to handle
24 days to re coat
(FPU top coat may be applied when Epoxy is dry to handle).
Induction Time 5 minutes at 70°F (See "Mixing" below)
Flash Point (Seta Flash) Component A - 125deg; F minimum
Component B - 128deg; F minimum
Color, Gloss White (semi-gloss), available in gray. Special colors subject to minimum order.
Pot Life 2 hours at 70° F (24° C)
Mixing Ratio 1 to 1 by volume
VOC Content 1.3 pounds per gallon (155 grams per liter, calculated)
Shipping Information 31 lbs per 2 gal unit - 1 gal Component A (Base) & 1 gal Component B (Activator)
134 lbs per 10 gal unit (5 gal. Component A (Base) & 5 gal Component B (Activator)
Freight PAINT, no label required.

IconSurface Preparation

Good surface preparation is essential to a satisfactory coating system. Surfaces to be coated should be clean and dry. Remove all oil, grease, mildew or other contamination by solvent or detergent cleaning or other effective means.


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.


Wash substrate from chlorides and allow to dry. Sandblast to create a 2.5 mils profile. Treat any holes, cracks, and joints by filling with acrylic concrete filler. Allow to dry. Apply by means of brush, SEAL IT to difficult and sensitive areas. Then apply by spray or brush all over the area SEAL IT. Allow to dry and proceed with applying the two coats of MOBAR W as per the recommended thickness. Concrete should be tested and treated for permeability. Do not expose concrete surface to permeability and make sure rebars or steel from rust contamination.


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 a 5 minutes induction time @ 70�F before using the coating. Usable pot life depends on the temperature of the material; refer to the Pot Life section (below). Agitate before use, with occasional stirring during use. As pot life expires, sag resistance may be reduced. Do not mix any more materials than can be applied in approximately 1 � hours @ 75�F.


Thin with � to 1 pint of No. 7537 thinner per gallon (if necessary) for spray application. Use No. 7535 for brush application. Add thinner only at a time of mixing. Do not add thinner to thickening material to extend pot life.

Icon Application

Spray application is preferred for proper film built and best performance. Brush application is acceptable for touch up and small areas. Roller application may require special care to prevent bubbling and may require more than one coat to attain proper film thickness. Apply @ 7.4 mils wet film thickness to achieve 6.0 mils DFT, unthinned.


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