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-----Fluoride is getting into etching bath
Hello
Can somebody tell me how fluoride gets into an etching batch in an anodizing line?
- Hoogezand, The Netherlands
June 12, 2009
First of three simultaneous responses --
Ammonium Bifluoride and Sodium Fluoride are sometimes added to the alkaline etch to create a finer grain. Maybe some suppliers are now adding it to their product. Some USA municipalities add fluoride to the drinking water.
Robert H Probert
Robert H Probert Technical Services
Garner, North Carolina
June 17, 2009
Second of three simultaneous responses --
Jan
Sodium fluoride is added to some (commercially available) etches for whitening and leveling characteristics.
- Colorado Springs, Colorado
June 17, 2009
Third of three simultaneous responses -- June 18, 2009
Jan,
Can you give us some more details of your process such as the chemistry of the etch tank, the chemistry of the other tanks used in the process, a list of any other tanks in the area.
Some of the proprietary etch salts have what is known as dry acid salts (sodium ammonium bifluoride or ammonium bifluoride). These dissociate when dissolved in water giving a source of hydrofluoric acid for etching.
If you are using a self formulated solution then we really need to know the solution chemistry before we can help.
Aerospace - Yeovil, Somerset, UK
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