BACKENING:

Parts which are to be blackened can be handled in baskets or continuously in the case of Wire. The nesting of the parts is to be avoided so that the free access of the solution to all Surfaces is not denied. Periodical shaking of the basket during the immersion period will Uniformly blacken the parts.

PROCESS:

The cleaned components are dipped in to the boiling bath. An immersion time of 10 minutes is Generally adequate to produce a satisfactory black. Alloys which have high Nickel and high Chromium content and cast iron parts look rusty when treated in FRANK BLAQ . The actual Treatment time depends on the surface finish, carbon content, alloying constituents and on the Physical state of steel whether annealed or heat treated.

High reflective surfaces produced by polishing or cold rolling will assume a highly glossy black Appearance. While non reflective surfaces produced by pickling will be changed to a dull jet black Colour.

The weight of parts immersed at any one time in the FRANK BLAQ bath should be controlled So that the temperature of the bath does not fall below 125°C otherwise non uniform blackening Will result, even though the temperature of the bath is brought up to the required operating Range of 140-150°C.

BATH MAINTENANCE:

The bath should boil at 140-150°C. If it boils below 104°C add more of FRANK BLAQ. If it boils at above 150° add more of water.

It is essential to maintain the bath in this boiling range and to maintain the bath level.

Maintenance of the bath level is done by employing a drip for water. This should be shielded to protect from spattering on the operator.

The salt in the solution will be gradually used up as loads are processed and the bath is replenished with addition of salts.

If the bath is highly concentrated, the boiling point will be elevated above 150°C and brown stain on the work will result. On the other hand, if the solution become too weak, transparent colours will be produced.

POST BLACKENING TREATMENT:

When the work has attained a jet black shade these should be thoroughly rinsed in cold running water to remove all traces of the adhering salt. If it is not done brown stain may occur at a later date. After rinsing, the components should be dried. Small components may be satisfactorily dried in a centrifuge.

Almost without exception the chemically blackened articles need additional protection to impart a pleasing black appearance and improve corrosion resistance. Frank range of Dewatering cum preventive oils- FRANK RUST TECH WD 1901/1902/1904 is recommended for the purpose achieving dewatering and prevention against rusting simultaneously. This application is done by brushing, dipping or by spraying.

SAFETY PRECAUTIONS:

FRANK BLAQ is a powerful oxidising agent and if mixed with combustible matter of any type, such as sacking, wood, paper ,oil, pitch, charcoal or sulphur, the mixture are easily ignited, and burn with great vigour. On the other hand when free from such material FRANK BLAQ is not combustible and very stable.

HANDLING PRECAUTIONS:

FRANK BLAQ is highly alkaline and any spillage of the solution either on the clothing or the body must be thoroughly washed with water. In case of spillage into the eyes wash with copious amount of clean water and obtain medical attention immediately.

FURTHER INFORMATION:

On application to our Sale Office, the visit of Technical Service Representative can be arranged to advice on the chemical processes for pretreatment of metal surfaces and prevention of corrosion.

IMPORTANT POINTS TO BE NOTED:

Operating Temperature:

The operating temperature of Frank Blaq will have to be between 140°C and 150°C. Also at any point of time the temperature of the bath shall not be below 125°C as any reduction below that temperature will result in non-uniform Blackening colour on the surface.

Bath Maintenance:

The Frank Blaq Bath when prepared according to the guidelines given in our Product Data Sheets, should boil at 140°C to 150°C. If it boils below 140°C,then more of Frank Blaq shall be added and if the boiling point exceeds 150°C addition of more water is required.

It is essential to maintain the bath in this boiling range ( 140°C to 150 °C ) along with the bath level.

Consistent Blackening:

In order to achieve consistent blackening of the component, we recommend to go for a pre-dip Bath prepared and maintained at the concentration and temperature of usual Frank Blaq bath, Please note that the immersion time in the pre-dip Bath shall be of 5 to 7 minutes only and thereafter it can be transferred to the regular Frank Blaq Bath wherein the component has to be immersed for 10 to 15 minutes.