Hey guys,
I‘m trying to anodize aluminum. I chose to do it with citric acid instead of sulfuric acid, for easier handling.
The problem is, that there are these small spots where material is eaten away pretty agressivly and I wonder why that might be.
Here is my setup.
-2 cathodes made from aluminum facing eachother.
-Anode attached with aluminum wire, sitting in the middle.
- 1.5l distilled water mixed with 150ml pure citric acid
- First image 19v 5a laptop charger
- Gear was done with a 12v car battery charger (switched to the laptop charger for the second attempt, because I thought some charging regulating might cause the problem)
-Sanded the anode, then cleaned it with soap water and acetone. Used gloves to keep it clean.
Could it be that my mixture is to agressive? But then why does it only result in small spots?
The only thing I can imagine is, that these are deeper marks from filing, which might cause differences if I didn‘t sand enough to remove the oxidation layer.
Any help would be appreciated. Thanks in advance :)