No nickel is deposited on iron
A little patience is required as nickel is deposited quite slowly. The current density may be too low, in which case it would take much longer. However, there should not be too many gas bubbles, otherwise black stripes could form.
The big disadvantage is that the nickel formation is also very difficult to recognise.
Also check the polarity of the anode again, this must be positive, while the object to be coated must be negative.
