TEKNODUR COMBI 770-500
Polyurethane paint
- Corrosion protective
- UV resistant
- 2-component
- Solvent-borne
- DTM (direct-to-metal)
- Topcoat
- Corrosion protective
- UV resistant
- 2-component
- Solvent-borne
- DTM (direct-to-metal)
- Topcoat
TEKNODUR COMBI 770-500 is a two-pack, fast drying, polyurethane paint containing zinc phosphate. The hardener is an aliphatic isocyanate resin.
Intended to be used direct to metal for anticorrosive systems in environments classified up to C2 and C3. Can be used as a topcoat in epoxy – polyurethane systems exposed in urban and industrial atmosphere. The product forms high decorative, semigloss coating, good adhered to substrate with good mechanical properties. Resistant to weathering, sun radiation, salt and alkali solutions, thinned acid solutions and petroleum products.
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). Roughening the surface of thin-plate improves the adhesion of the paint to the substrate.
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.
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.
Application
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. Inadequate stirring or incorrect mixing ratio results in imperfect curing and impaired film properties.
Stir thoroughly before use.
Apply by airless spray, brush, roller, and after diluting – conventional spray.
Suitable airless nozzle size 0.011 - 0.013".
Before use clean the spray gun and mixing vessels with a thinner TEKNOSOLV 9521 or TEKNOSOLV 433.
If a coating with better scratch resistance is needed, instead of the standard hardener TEKNODUR HARDENER 7332, use TEKNODUR HARDENER 7332-01 in the same mixing ratio. Using this hardener will not change the pot life and the drying properties of the coating.
Do not use universal thinners, since they may contain alcohol which will react with the hardener.
Application conditions
The surface to be treated must be dry and the relative air humidity below 80%. Minimum surface temperature -5°C (surface frost- and ice-free) and at least 3°C higher than dew point during the application and drying period. Adequate ventilation during application and drying period is recommended.
Storage
The storage stability is shown on the label. Store indoors in a cool and dry place and in a tightly closed can.
The hardener reacts with air humidity and therefore the can is to be kept carefully closed. Use opened hardener within two weeks.
| Total mass of solids | abt. 820 g/l |
|---|---|
| Volatile organic compound (VOC) | abt. 430 g/l |
| Pot life | 2 h (+23 °C) |
| Mixing ratio | 100:9 by volume (comp. A : comp. B) |
| Hardener | Comp. B: TEKNODUR HARDENER 7332 |
| Gloss | Semi-gloss |
| Tinting system | Teknomix |
| Practical spreading rate | The values depend on the application technique, surface conditions, overspray, etc. |
| Drying time – dust free | after 40 min |
| Drying time – touch dry | after 2 h |
| Thinner | TEKNOSOLV 9521 - slow evaporating, TEKNOSOLV 433 - fast evaporating |
| Clean up | TEKNOSOLV 9521, TEKNOSOLV 433 |
| Colours | The paint is available in base colors intended for coloring system. After agreement, selected colors are available in factory colors. |
| Safety markings | See safety data sheet. The hardener of the product and the ready mixture contain isocyanates. In poorly ventilated areas and especially when using spray application we recommend the use of a fresh air mask. In short or temporary work, a mask with combined filter A2-P2 can be used. In this case eyes and face are to be protected. The hardener can must be opened with caution, as pressure may develop in the can during storage. |