Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Effects of fluoride in rinsing streams for anodizing and chromate lines
We have a customer requirement for etching extrusions that require a dull matte finish. We currently use Caustic at about 50-60 g/l concentration with an aluminum content of 140-150 g/l at a temperature of 140-150 Degrees F. for 15-20 minutes. We are considering using an acid etch 5% Ammonium Hydrogen Fluoride at 115-120 Degrees F. The results of the acid etch have been good; but we are concerned with carrying fluoride down the line after rinsing. We understand the advantages of less time, duller finish and ease of rinsing; but what are the negatives of incorporating fluoride into the pipeline?
Joseph Hillockaluminum finisher - Philadelphia, Pennsylvania
August 20, 2009
Two for sure. the higher cost of the material with a similar or shorter useful life and the high cost of waste treatment in some places.
James Watts- Navarre, Florida
August 22, 2009
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