Advice on correct preparation and painting on galvanized metal
Galvacoat can be applied by brush, roller or spray equipment. It has very good resistance to UV exposure and can therefore be applied as a one coat system for painting galvanised steel in outside weathering conditions.
The galvanizing to be coated must be free of dust, rust, oil, grease and soluble salts (white rust). After welding, any damage to a galvanized film should be cleaned and any rust removed. A cold galvanised material with a minimum zinc content of 92% should be applied to the damaged areas at a minimum thickness of the galvanized film plus 10%. A combination of degreasing and steam cleaning is the optimum way to remove any dirt, grease and zinc salts. Wash down with fresh water.
Add the hardener to the base paint (converter) and mix well.
Airless application: Dilute 0-10% with thinner PU41 Airmix application: Dilute 5-10% with thinner PU41 Air assist application: Dilute 10-20% with thinner PU41 Recommended spray nozzle size for airless spray : 0.015-0.017”; 50-80 degree angle
Relative air humidity: max 85% (no condensation on the substrate) Temperature during application and drying: 2C above the dew point. Never apply below 5C. Max. temperature during application: 40C
Dustfree: 1hr Tack free: 4hrs Hard: 20hrs Recoatable: 12hrs Recommended thickness: 40 – 120 microns Potlife: 6 – 8hrs at 20C
For Best Application Conditions Remember:
- Always ensure that the galvanizing is clean and dry and that any zinc oxide (white rust) has been removed.
- Add all the hardener to the base and stir together well, once. Do not continually stir as agitating the material only serves to generate heat which reduces the pot life.
- Do not apply GALVACOAT when it is raining or the temperature is likely to go below 5C within 2-3 hours.
- When applying a light colour (white, yellow), it is advisable to stripe coat all edges and vertical surfaces with GALVACOAT before applying a full coat, as it is difficult to get sufficient material on an edge to cover in one coat of a light colour.
- Ensure that no more than three days passes between the cleaning down of the galvanizing and the application of GALVACOAT.