PREPARATION STAGES OF METAL SURFACES BEFORE APPLICATION
The metal surface must be completely cleaned before applying the adhesive. A good preparation of the metal surface is required to obtain a good metal/rubber bond and to be resistant to water and corrosion. The oxide layers on the metal surface should be mechanically cleaned. The metal surface is basically prepared by two methods.
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Mechanical Cleaning:
Grit blasting is a recommended method of metal cleaning. Steel grit is used to blast clean steel, cast iron; for other nonferrous metals, the use of aluminum oxide is recommended.
Layover time between blasting and adhesive application should be kept to a minimum in order to avoid oxidation.
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Chemical Cleaning:
The process of chemically preparing the metal surface requires a different application for each metal group. Phosphating is a widely used chemical process for steel. The process applied under the paint in the aluminum surface coating process is called chromate.
APPLICATION
Mixing – KA&MELOCK KM 20 should be stirred thoroughly before use and during using to keep dispersed solids uniformly suspended.
Applying – Brush, roller, dipping or spraying methods can be applied for KA&MELOCK KM 20.
• Brushing/Roll Coating Undiluted
• Dipping Dilute bonding agent with up to 10% of xylene or toluene.
• Spraying Dilute bonding agent with up to 40-60% of xylene or toluene to a viscosity of
18-20 seconds (4mm DIN-Cup)
Experience has shown the following thickness of Primer and Bonding Agent provide the best result:

Primer approx. 8 μm – 10 μm
Bonding Agent approx. 10 μm – 15 μm
Drying- The bond coating can be dried at least 30 minutes at room temperatures. By using hot air drying up to 70 °C.; the time can be shortened. Metal parts with the Primer of Bonding Agent can be stored for several days in a clean environment.
Clean Up- Use xylene or toluene for clean-up.