Dull zinc plating, patchy black oxide, non uniform brass antique/patina caused from metal cleaning problem. Cleanliness is next to Godliness.
Posted by Eric Olander on
By Eric Olander
We have all heard beingcleanisasignofspiritualpurityorgoodness,asin don'tforgetto washyourears—cleanlinessisnexttogodliness. Thisphrasewasfirst recordedinasermonbyJohnWesleyin1778,buttheideaisancient,found inBabylonianandHebrewreligioustracts.Itisstillinvoked,oftenasan admonitiontowashorcleanup.
A cleaned metal (steel,copper,brass zinc,stainless steel, aluminum and plus others) surface is good for all types of metal finishing.
The two zinc plated parts above show how a dirty part can cause a dull zinc plated finish. Operator tendency will be add more zinc brightener thinking a zinc plating problem of being low in brightener. The only difference in the two parts is the cleaning chemistry as they were both plated out of the same zinc bath.
Parts not blackening? The video below speaks for itself.
The first time you see the panel being pulled out of the Insta Blak 333 you can observe the blackening solution running of and leaving a bead/streak of solution. If the part was cleaned the solution would blacken the part and and the solution would uniformly wet the surface.
EPi has cleaning processes for:
Electroplating E-Kleen SR line for soak and electro clean applications.