The authoritative public forum
  for Metal Finishing since 1989
-----

The Anodising Sealing Process

My name is Mobius Shumba and I am working as a Quality Assurance Officer.
My question is very interesting and I hope to get a favourable reply.

Narration:I have got a problem with traces of smut which appear on the anodised material after sealing. This problem occurrs and there a problem of detecting it before it occurs.

Question: How can I detect the problem of smut before it affects the anodised finish

Mobius Shumba
Quality Assurance Officer - Harare, Zimbabwe
2007

---

Mr Shumba,

What kind of sealing process are you using?, cold sealing with nickel salts or hot water sealing.
Hot water sealing produces a white dust in the surface, you can try any anti-dust product, ask your supplier. Cold sealing process can produce a chalky appearance of the material it's necessary to check pH, Temperature, concentration and the immersion time according to your supplier specifications.
It's also interesting if you can tell us more about your process, because smut it's produced, normally, with the alkaline etching or after the bright dip bath and it's necessary to dip in a deoxidizer solution prior to anodization step. Some times if you don't deox the pieces correctly, the smut remains over the surface after the hole process.

Regards

Sergi Fernández
- Spain
2007