Epoxy phenol novolac coating

  • Chemical resistant
  • Corrosion protective
  • Wear resistant
  • 2-component
  • Solvent-borne

INERTA 280 is an almost solvent-free epoxy coating based on epoxy phenol novolac resin.

The coating is used in epoxy coating systems for coating steel and concrete surfaces submerged under mechanical and chemical strain. INERTA 280 has good adhesion to blast cleaned substrate and excellent wear resistance. INERTA 280 withstands well chemicals like saline solutions, alkaline solutions and mild acids. The resistance to aliphatic and aromatic hydrocarbons like solvents, oil and petrol is good. Withstands also water-ethanol blends. APPROVALS: The product has CE approval for protection of concrete structures.

Surface preparation

Remove from the surfaces any contaminants that might be detrimental to surface preparation and application. Remove also water-soluble salts by using appropriate methods. The surfaces are prepared according to the different materials as follows: STEEL SURFACES: Remove mill scale and rust by blast cleaning to preparation grade Sa 2½ (standard ISO 8501-1). The profile of the blast-cleaned surface must be at least coarse (reference comparator "G"). See standard ISO 8503-2 (G). CONCRETE SURFACES: The concrete must be at least 4 weeks old, well-hardened and solid. The water content of the top layer must not exceed 4% by weight. Smooth down any spatter and irregularities on the surfaces by grinding. Brush away loose cement, sand and dust. Wash oily and greasy surfaces with detergent or solvent. Remove dense laitance if present by etching with RENSA ETCHING etching liquid or by grinding or blast-cleaning. OLD PAINTED SURFACES SUITABLE FOR OVERCOATING: Any impurities that might be detrimental to the application of paint (e.g. grease and salts) are removed. The surfaces must be dry and clean. Old, painted surfaces that have exceeded the maximum overcoating time are to be roughened as well. Damaged parts are prepared in accordance with the requirements of the substrate and the maintenance coating. Before or after the first coat all dents and holes on the surface are to be filled with epoxy putty, which is prepared by mixing fine dry quartz sand with INERTA 280 mixture. The place and time of the preparation are to be chosen so that the prepared surface will not get dirty or damp before the subsequent treatment. Additional instructive information for surface preparation can be found in standards EN ISO 12944-4 and ISO 8501-2. Prefabrication primer: All prefabrication primer coats must be completely removed regardless of the binder type. In practice this means that when the surface is viewed vertically from a distance of 1 meter and in normal lighting conditions the surface is of an evenly grey colour, i.e. the preparation grade is Sa 2½ (ISO 8501-1).


MIXING OF THE COMPONENTS: Take into consideration the pot life of the mixture when estimating the amount to be mixed at a time. Before application the base and hardener are mixed in right proportion. Stir thoroughly down to the bottom of the vessel. Mixing by machine is recommended, for example a slow-rotating hand-drill equipped with a mixer. Inadequate stirring or incorrect mixing ratio results in imperfect curing and impaired film properties. BY TWIN-FEED SPRAY: For demanding areas it is recommended that the application is done by a hot twin-feed spray, e.g. Graco Hydra-Cat. Suitable nozzle size (turn-nozzle) 0.018 - 0.026". The components must be kept at a temperature of +20 - +25°C before use so that they are fluid enough for the feed pumps. The ratio of the dosage pump must be 2 : 1. The heating of the components shall be adjusted so that the temperature in the gun is +30 - +40°C. The pot life of the mixture is then 10 - 20 min. If necessary, the hoses must be heated. The film thickness is controlled by a wet film gauge. The feed pump pressure and the consumption of components is to be checked to ensure of the correct mixing ratio. To fill the pores in concrete surfaces, a coat of 200 - 300 µm is first sprayed and smoothed by brush or rubber spatula over porous areas. Immediately thereafter another coat is applied to achieve the total coat thickness of 500 µm. Directions given by the manufacturer of the twin-feed spray are to be followed when working. WARNING! The amount and the temperature of the mixture will affect the pot life. The spray equipment will be damaged if the paint is let to cure inside it. If the interval between the coats is 1 - 2 days, good adhesion can be ensured by wiping the surface with thinner TEKNOSOLV 6560 or TEKNOSOLV 9514, which softens the paint film and makes it sticky. Whenever the maximal overcoating interval is exceeded, the adhesion can be secured by rubbing down the surface.

Application conditions

The surface to be treated must be dry. During the application and drying period the temperature of the ambient air, the surface and the product shall be above +10°C and the relative air humidity below 80%. Additionally, the temperature of the surface to be treated and the product must be at least +3°C above the dew point of the ambient air.


INERTA 280 can be thinned max. 5% with TEKNOSOLV 6560 or TEKNOSOLV 9514 for painting small areas and for touching up or repainting. The paint is to be applied with an efficient airless spray or with a brush. Immediately before use the components are mixed in correct mixing ratio. The mixture is stirred thoroughly with a drilling machine. Before spraying the mixture is circulated through the hoses back to the mixing vessel until the mixture is warm.


The storage stability is shown on the label. Store in a cool place and in tightly closed containers.
Total mass of solids abt. 1500 g/l
Volatile organic compound (VOC) abt. 50 g/l
Pot life 40 min. (+23 °C)
Mixing ratio 2:1 by volume (comp. A : comp. B)
Hardener Comp. B: INERTA 280 HARDENER
Gloss Gloss
Practical spreading rate The values depend on the application technique, surface conditions, overspray, etc.
Drying time – dust free 3 h (ISO 9117-3:2010)
Drying time – touch dry 4 h (ISO 9117-5:2012)
Drying time – fully cured 7 d
Thinner (max. 5%) TEKNOSOLV 6560, TEKNOSOLV 9514.
Clean up TEKNOSOLV 9530 The painting equipment must be cleaned immediately after use. The hose and gun must also be rinsed with paint's own thinner during the work after every 20 - 30 liters batch.
Colours Red, green and white. Other colours by agreement. NOTE! Sunlight and chemicals cause the colour and glossiness to change in time.
Safety markings See safety data sheet.
Approvals & certificates CE marking