TECHNICAL DATA SHEET
GALV TECH ZINC COATINGS
GALV TECH Zinc metal coatings are designed for corrosion protection and prevention. They can also be used for cosmetic finishes. We have a number of sprays and pastes developed for various types of application and quality finishes. Some have been developed specifically for the renovation and repair of hot-dip galvanizing processes and to assist their protection against corrosion in its various forms.
GT ZINC SPRAY
Complies to BS/EN/ISO 1461. GT Zinc Spray contains 98.5% to 99% pure Zinc. The Zinc pigment in the dry film is in excess of 90% and provides excellent cathodic corrosion protection.
Simple in application - shake the can for at least 30 seconds after the mixing balls have been heard to obtain a really good mixture. Finger pressure is all that is needed to produce a continuous protective spray. The surface should be free of rust, oil or grease. Spray at a distance of 25/30 cm(10 inches) in a free flowing motion. Multiple thin coats are preferable to one thick coating. Allow at least 20 minutes between applications.
Reliable in action - GT Zinc Spray combines the proven reliability of zinc-based surface protection with the advantages of an advanced synthetic resin coating, combined with a leaf-Zinc particulate, which affords the substrate metal a cathodic rust-inhibiting finish. This combination provides protection which surpasses the DIN Salt Spray Test to 240 hour.
Always in ready-to-use form/quick drying - sprays as a homogeneous coating. This will be touch dry after 30 seconds for welding and waterproof within 15/20 minutes. There will be no shrinkage, no hair-line cracking. The surface can now be painted or primed without any further treatment. The surface finish will be matt-grey in colour.
No repair or assembly shop should be without it - for rust protection and priming. Ideal for touching up damaged zinc coatings as conductive interlining for spot welding, eg all vehicle bodywork and panel welding. For re-coating over drilling marks and weld lines. Used as a primer for constructions exposed to water and weather. For poles, masts, pipelines, sewage plants, sheds, heating systems and construction, railings, port installations, ship superstructures and marine use generally. For protection against various gases, acids and alkali solutions. Economic in application - a single short spraying is sufficient to produce a 40-60um thick protective coating.
The following table shows the recommendations of BS/ISO/EN1461:
TABLE 1 : ZINC SPRAY FILM THICKNESS TO BS/ISO/EN 1461
Material Thickness Recommended Zinc Film Thickness Recommended Zinc spray Film Thickness to 1.5 mm 45um 75+ um 1.5 to 3 mm 55um 85+ um 3 to 6 mm 70um 100+ um from 6 mm 85um 115+ um
These recommendations are in effect to give the component the same 'life' as if they had been Hot-Dip Galvanized to the BS/ISO/EN specification.
Corrosion Protection depends very much on environmental conditions - weather, salt water etc. What is acceptable for normal hot dip galvanized components is acceptable for GT Zinc Spray if the recommended film thicknesses outlined above are complied with. Temperature resistant to 400 C. Zinc Spray is also available in Liquid Zinc "brushable" format.
GT ZINC SHEEN SPRAY
This product gives a partial 'gloss' and finish comparable with hot-dip galvanized structural steel. Technically similar to GT Zinc Spray but with an approx 5% replacement of Aluminium giving a combined high content of metal in the dry film along with the cosmetic effect of hot-dip galvanizing. All other technical details are as GT Zinc Spray.
GT LIQUID ZINC
A similar technical specification in every respect to GT Zinc Spray. It is primarily a BRUSHABLE product, but may be used in conventional. The surface finish is matt-grey in colour. Available in 250, 750ml and 2.5ltr containers.
GT Liquid Zinc can be airline sprayed with a light dilution of 'thinner.' Ideally this should be to a maximum of 5% to maintain the specified concentration of Zinc. It is essential that it is thoroughly dry before overpainting. GT Liquid Zinc up to 120um can be applied in a single brushing application, although multiple light coats are preferable to one thick coat. Drying time is dependent on brushing thickness but a minimum of 30 minutes should be allowed for a light brushing to be 'touch dry'. Temperature resistant to 400 C.
GT ALU ZINC SPRAY
Slightly brighter (cosmetically) than Zinc Sheen, The use of the revolutionary Zinc-flake, combined with aluminium pigments, ensures the highest cathodic protection available and a finish similar to hot-dip galvanized parts. This product also surpasses the DIN standard Salt Spray Test for 312 hour and is available in brushable format. GT Alu Zinc applied over hot dip galvanizing can also extend the protective life of the original product.
Temperature resistant to 500 C.
GT ALU ZINC BRUSHABLE
Specification similar to GT Alu Zinc Spray, available in 250ml,750 ml and 2.5ltr containers. Application is possible by brush, roller and spray.
GT COLD GALV- SPRAY
Brighter finish again than Alu-Zinc. This product provides a cosmetic finish similar to the brightest Hot Dip Galvanizing, with excellent corrosion protection. Out-shines its' competitors in every respect. This product is also available in 5ltr containers
a. Zinc dust pigments in paints have a tendency to separate out into inconsistent densities. The Zinc metal usually remains in a solid mass in the bottom of the paint tin and cannot be re-mixed into a consistent homogeneous liquid, thereby defeating their own purpose. The advances in flake/leaf pigments used in Galv Tech products do much to aid the special formulation designed to prevent this.
b. Many conventional zinc-dust based materials are unsuitable for over-painting, particularly those that also contain aluminium pigments for cosmetic purposes. The Zinc-flake pigments used in many of the Galv Tech products also allow improved cohesion and adhesion of the film, thus reducing the potential for problems with subsequent paint coats. Please consult with our technical desk for further information.
SURFACE PREPARATION FOR GALV TECH METAL COATINGS
For best results care is needed in the preparation of surfaces prior to application of all Metal Coatings. Where parts have been welded, the 'welds' should be dressed with a grinder and then the whole surface abraded with ZK60 grit leaf disc where application of the Zinc Metal Coating is required. This gives a 'key' for the metal coating. The surface should then be cleaned to remove grease, oil and surface deposits. GALV TECH Metal Coatings can then be applied.
Application in temperatures below 5 C are not recommended, as there will always be the potential for problems with condensation on the substrate below this temperature. The ideal minimum temperature of 10 C will allow the solvents to evaporate in a reasonable time. The maximum recommended application temperature is 25 C.
Multiple 'thin' coatings are more practicable than one thick coating. Each coating should be allowed to dry thoroughly between applications. Three thin coatings will meet BS/EN/ISO1461 and DIN 531671/50021 for most applications. See table 1.
OVERPAINTING OF GALVANIZED PARTS
There are many instances where the main customer's specification requires the overpainting of galvanized parts. This means that invariably the component will have been hot dip galvanized and where appropriate repaired to BS/EN/ISO1461, by the use of GALV TECH Zinc based products.
Where overpainting of the galvanizing and the repaired areas is required there are features of the paint of which the applicator should be aware. Many paints used Xylene, Toluene, MEK and similar solvents which are listed in the COSHH 1988 regulations as hazardous materials. They are also listed under EPA guidelines as hazardous pollutants and classified toxic.
Conventional high quality brushable paints normally contain 30/40% solids and do not exceed 40/60% solvents. These are quite acceptable as 'primers' providing that individual brushed coatings do not exceed a thickness of 80um. It is essential that each coating is allowed to dry thoroughly before additional coatings are applied. This is to allow complete dispersion of the paint solvents to atmosphere. If this procedure is adhered to, there will be no adverse effect in the repaired areas.
We are advised that there is pressure from the EPA on manufacturers to increase the solid content of paint to 70% or more by 1998. (50% solids for water based paints). This will have benefits not only for improvements in quality, but for Health and Safety in application.
HEALTH AND SAFETY
All GALV TECH aerosolised and brushable products conform to the current EEC Regulations for Health and Safety. Aerosols should be sprayed only in well ventilated areas, and should not be stored in direct sunlight or in temperatures exceeding 50 C. On complete depletion the cans should be placed with normal solid waste disposal, or as required by local regulations.
Should the product come into contact with skin, it is not hazardous and can be cleaned off with normal industrial hand cleaner. If the product and propellant is sprayed into eyes, they should be flushed with a copious amount of cold water and a doctor consulted. If inhaled, rest and quiet is necessary until normal breathing returns and consult a doctor.
WARRANTY AND DISCLAIMER
The information given in this data sheet is based on many years experience and is correct to the best of our knowledge. However, since the use of our products in accordance with the instructions given and their success in applications is dependent upon a number of factors, we can only be responsible for the quality of our product at the time of despatch. Should any doubt arise about specification or application, our technical service department should be contacted immediately. As the information given herein is of a general nature, we cannot assume any responsibility. Success will always depend on the peculiarities of the individual case. We also refer to our standard conditions.