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-----Stains and stress marks on clear anodized
I work for a company that manufactures aluminum doors and usually uses organic coatings for their products. Right now we are working on a 204-R1 clear anodized job and are having two problems with the finish: 1.- The oil used to refrigerate the saw is staining the aluminum extrusions, leaving a white stain. Is there any way of getting rid of these stains? 2.- Some pieces need to be punched in a punch press, and we are getting some stress marks near the punched area (as if the finish is cracking). It doesn't happen when using a polyester paint.
Jorge Santaella- Miami, Florida
We have had experience with white stains from oils/grease. This was when we thought that we had we got rid of the oil with the minimum immersion time in the alkaline cleaner.
The problem was solved after we placed the parts in the soap much longer (and in the etch tank, too). This may have worked for us since the soap is compatible with the oil used. Check if your cleaner works for your oil type.
I haven't heard of any process in anodizing that will hide the stress marks. I'll be monitoring any more response to your inquiry and perhaps somebody may have solution for this.
Dado Macapagal- Toronto, Ont
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