Zinc plating coming out grey

[DCLXVI]

I’ve just begun zinc plating and my first batch of six bolts were beautiful. Every batch after is coming out grey. I’m very careful with cleaning and using separate rinse buckets. I calculate amps carefully and even tried lowering amps from my calculations with no luck. Any advise

[FASTLIKEJUDY]

Greetings DCLXVI, Your yellow chromate hardware looks good. I assume the large plates are what you are referring as being grey. The plates look like they are about 8 inches diameter which may exceed the capability of your system. To plate properly I believe the sacrificial zinc plates should be at least the same size as the piece you are trying to plate.
When I have problems the first thing I look at is the brass wire that is hannging the piece. If the plating on the wire is good I look towards cleaning and prepaation of the piece. Can you plate smaller hardware and get satisfactory results?
That is about the extent of my insight. Please let us know how it works out.
Thank you
KRR

[Revival Road Fab Works]

It's hard to judge the size of those pieces, are they washers for the hardware or larger plates that are a couple of inches in diameter??

Judging from a piece I attempted to plate that was well over the square inches my 5 amp rectifier could handle your rectifier is simply too small. But we'd need more information from you.

[DCLXVI]

The washers are about 2” across. My power supply I believe is 10-15 amp. I can turn it up enough to get a hard foaming coming off of the parts so I don’t think power is an issue. Haven’t had any time to get back to it but I was going to strain my bucket through coffee filters and try again