Steel - The surface should be blast cleaned to SSPC-SP 10-63T or NACE No. 2 i.e. loose rust and scales, dirt, grease, oil, paint, wax, weak oxide films and other contaminants should be removed. Blast cleaning to SSPC-SP 5-63 or NACE No. 1 is recommended where heavy corrosive conditions exist or coating is required to be immersed. That means a surface with a grey metallic colour, slightly roughened to form a suitable anchor pattern for coatings. This surface is free of all oil, grease, dirt, mill scale, rust, corrosion products, oxides, paint and other foreign matter. In absence of blast cleaning, prepare the metal surface by wire brushing, sanding, grinding, scrapping or chipping with hand or power tools. Remove all the contaminants.
Non-ferrous Metals - The metal surface should be grit or sand blasted to ensure complete removal of loose particles and slightly roughened to form a suitable anchor pattern for coatings. Remove dirt, dust, oil, old paint etc. Degrease the surface with degreasing solvents like xylene or tri-chloroethylene. Apply one coat of Anuprime - 291 Wash Primer for obtaining maximum adhesion.
Concrete: New or poured concrete contains a considerable quantity of surplus water. For best results, new concrete surfaces should be clean, dry and well cured before coating. New concrete allowed to cure or aged for minimum of 30 days at temperatures over 25° C prior to surface preparation and coating application which will help assure maximum performance of the coating system and satisfactory coating adhesion.
New or old concrete should be grey or grey-white color and free from pits, pockets and holes. Prepare the surface with abrasive blasting or power tools. Surface imperfections should be filled in with DURAPATCH. No cement dust or sand should be dislodged. It is always recommended to clean the surfaces with abrasive blast cleaning. In absence of blasting, etch the surface with 10-15% muriatic acid diluted in water. Allow this acid solution to remain on the surface for 10-15 minutes or until the bubbling stops. Thoroughly rinse the floor with water to remove all traces of acid. Allow the floor to dry completely before painting.
Concrete surface requiring a primer should be primed with Chemoguard # 888 Primer reduced 33% with Anusol - ETP Epoxy Thinner for assuring maximum penetration of the coating into the concrete and a better bond of coating system to the substrate. After the initial coat has dried for 24 hours, apply 1 full coat Chemoguard # 888 Primer followed by two coats of Chemoguard # 999 Topcoat.
Curing:
Chemoguard coatings can be applied to wet surfaces when the ambient temperature is as low as 0° C. Do not apply when temperature can be expected to drop below 0° C within 6 hours after application. Under these conditions, the cure will be very slow but not otherwise affected. These coatings have the ability to harden even at 0° C but subsequent exposure to high temperatures is necessary to cure. Complete curing of the system takes place at room temperature in 7days. However, the room temperature should not be below 20° C. Post curing at 70-80° C for few hours is strongly recommended. Infrared lamps, steam and hot water can effect post curing. Post curing enhances the mechanical strength besides ensuring complete curing.
Pot Life:
Working Pot life after mixing base and hardener is 45 minutes to1 hour at 25° C. At higher temperatures, the pot life of the material is drastically reduced. It has been noted that packing ice around the mixing or spray pressure pot will extend pot life.
The material will dry to touch within 5-7 hours with significant toughening of the film overnight and full curing 7 days at 25° C. Allow the primer coat to gel to the tacky stage and at this stage further coat is applied so as to ensure maximum adhesion between the two coats.
Mixing Instructions:
When the temperatures are higher than 25° C, refer to above paragraph on "Pot Life" to determine the quantity to be mixed. DO NOT MIX MORE THAN CAN BE USED WITHIN 1 HOUR.
Mix 2 parts of base with 1 part of hardener by volume. Continue mixing for 5 minutes minimum to ensure proper mixing.
Thinners:
In exceptional circumstances, ANUSOL-ETP Solvent in amounts upto 10% may be added to this coating system for ease of application. Neither alcohol, higher ketones nor glycol ethers should be used since these solvents impair the water resistance of the cured films. When the coating contains solvent, dry film thickness of the applied coating should not exceed 150 microns.
Chemical Resistance:
Lack of Chemical Resistance is not the most common cause of coating failure. Inadequate surface preparation or application of coatings under less than ideal conditions responsible for coating failure. Chemoguard coating system has been designed to tolerate adverse conditions of surface preparation and application albeit with shorter life for all types of service except immersion. The stressed of immersion service are so great that the best surface preparation possible must be specified. Chemoguard Coating System is not recommended for immersion service except with specific reagents but its use for splash and spillage service is almost unlimited. This system is suitable for immersion service at 25° C in the under mentioned chemicals |
