Problem: The blacked finish is uneven black, specked or patchy
A patchy finish is most often caused by the component not being clean enough when it enters the blacking tank
- Check degreaser for oil contamination.
- Check the components are being left long enough in the degreaser.
- Ensure the degreaser is being used at correct working temperature.
- Ensure the degreaser is up to strength. Poor rinsing can lead to a component not being clean enough to black successfully.
- If static rinse tanks are in use, change rinse water more often and consider using running water rinses.
- If running water rinses are in use consider increasing flow rate.
- Consider introducing air agitation into rinse tanks to aid rinsing.
If the above suggestions do not solve the problem consider using a stronger degreaser, for example Blackfast 626 hot powder degreaser. The above suggestions apply equally to the use of a hot degreaser.
If the patchy finish is on parts of a component that has scale or rust on the surface replace Blackfast 551 conditioner with Blackfast 513 acid pickle