Manganese phosphate problem

hi

I want to make manganese phosphate solution but when I put parts in solution for first time the parts has reaction for longer time and it's coating not stable when in adding some carbonate manganese to the tank it go better. I think I don't make it proper.
please tell me about percentage of NaNO3 and NiNo3 as accelerators.
and how can I produce coating refiner for manganese phosphate?
carbonate manganese is suitable or manganese oxide?
best regards,

Hello!

Well you make whatever solution concentration, but remember that when you have made a fresh solution of phosphating just take some iron scrap in a bag, e.g., in a shieve and let it there for half an hour and then start phosphating. I think that you were missing to activate iron.
Hope it works for you

thanks