After anodizing we found yellow stains on anodized surface. Result of chemical analysis revealed presence of following substances elements:
Ca, Na, Fe, Cl, K.
Additionally we observed discontinuity of anodized layer.
Could anybody explain me what was the reason for showed stains?

Thanks in advance for your support

After anodizing we found yellow stains on anodized surface. Result of chemical analysis revealed presence of following substances elements:
Ca, Na, Fe, Cl, K.
Additionally we observed discontinuity of anodized layer.
Could anybody explain me what was the reason for showed stains?

Thanks in advance for your support

Most stains are caused by contamination (not cleaned properly) at least in my experience.

Most stains are caused by contamination (not cleaned properly) at least in my experience.

It sounds and looks like either cleaning or sealing solution bleed out from the discontinuities in the material. Are the hardness and conductivity readings good in that area?

I don't know much about anodizing but when I see sodium, potassium and chlorine showing up in a chemical analysis I'm thinking someone has had their hands on the material.

If someone touches the metal pretreatment without gloves on is this likely to affect the anodizing process? as this will leave a residue among which you will certainly find sodium. potassium and chlorine.

Water contaminated by treatment chemicals was probably used in the rinse as well as Fe from the water lines themselvesis my guess. If it isn't a direct contamination it could be indirect from a siphoning action between procress treatment (output) and and process flow (input)