Thanks.
I spoke to a guy today who has been in the anodising industry for 30 years. He said that he used to use a vibratory tumbler to desmut, or just warm soapy water after the etch. he would then rinse and re-etch for a couple of minutes.
He also mentioned the need to vigorously agitate the anodising bath with compressed air - he said that it helped cool the solution, as well as preventing localised defects. Makes sense to me.
So, to summarise - it doesn't really matter how you clean/etch/desmut, as long as you present a clean piece of aluminium, with no oxidation, grease or smut, to the anodising bath?
The guy mentioned above also said that automotive alloys (which I will mainly be working with) tend to have a very high silicone content, and are very difficult to desmut properly. Anyone had any experience with these alloys?
There is a company over here working on a new chemical desmut for these alloys, but it isn't ready yet.
Thanks for all the help!
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