Enamel Preparation and Application
Enamel should be broken up into small pieces, approx. 2 kg and loaded into the kettle. For the first 30 min. heat should be applied slowly until there is a quantity of molten enamel on the bottom of the kettle. After this the burners may be increased to full output and the kettle fully loaded, using pieces of enamel not more than 9 kg weight. Kettles used previously for Bitumen (asphalt) should be thoroughly cleaned before use and vice versa. The quantity remaining in the kettle on re-heating should not exceed 10% of the fresh charge.
It is of the utmost importance to have a calibrated temperature recorder fitted to the kettle at all times, and should be checked periodically.
The enamel should be stirred at all times during use, except during re-loading. The lid must be kept closed at all times to avoid loss of volatiles.
In the event of plant breakdown, or for any other reason, heat should be withdrawn from the kettle and the enamel temperature dropped to approx. 200°C (400°F) and kept at this temperature and still agitated until ready for use. The maximum temperature in the kettle should never exceed 260°C (500°F). Enamel above this temperature should be rejected. Enamel held at application temperature for more than 4 hours should also be rejected.
Enamel should not be applied to the primed pipe when the metal temperature is below 7°C (45°F) and care should be taken to ensure that the pipe is free from dust, dirt, oil and moisture.
If the speed of operation or high ambient temperatures prevent the pipe from hardening sufficiently, it is advisable to use water quenching to avoid skid damages. 'V' boards are recommended for storing the completed pipe section. This helps prevent damage and facilitates holiday detection and repairs. After this the completed pipe can be stacked. This should be done using sand or straw filled bags as spacers.
Health & Safety
Solubility in water - insoluble
Flash point
- In solid form - None
- In liquid form - 250°C
Fire-extinguish with CO, Dry powder or fine water spray.
Personal Hygiene: The use of gloves and filter type face mask is recommended in the appi ication area. Do not smoke while using Coal tar enamel. Do not use solvents to wash skin.
Ventilation: Must be adequate in application and heating areas. Avoid working in confined spaces.
Eyes: Eye protection is recommended and should be available at all times, in the event of accidental contact, wash eyes with cold water and seek medical advice.
Skin: Barrier cream should be applied to the skin before commencing work. In case of skin contact with hot enamel, immerse in cold water.
Storage: There are no special arrangements for storage of solid enamel, although storage in shaded area is helpful when breaking up enamel.