[f_sigona]

Hi Guys,

I am having simmilar problems to yours.
Did anyone manage to solve this issue. What type of surface prep are you using and are you etching in any acid and rinsing before the parts go into the blackening solution. Another question i have is are you using the blackening solution at full strength or diluted? Will this have any effect?

From experiments i have conducted on four identical components i have only got one to come out well so i am lacking consistency. Process was as follows:-

Degreasing
Rinsing
2 min dip in HCl 50% solution
Rinsing
2 min dip in Blackening solution
Rinsing
Drying
Heat in oven 250 deg C for 15 mins
Water quench

Any suggestions are welcome

Thanks.