Re: Hard Anodizing
Oxalic acid is often used for type III anodizing. I tried it at home once as an experiment and got a nice solid gray/green finish like I usually get from commercial hardcoat treatments. Have no idea what the coating thickness was, but it looked cosmetically good. I didn't try to dye it. Oxalic acid baths do not need refrigeration. Oxalic acid can be bought in the paint department at most home centers as "wood bleach". A white powder. More expensive than sulfuric acid, but not unreasonable. Needs a higher voltage than sulfuric anodizing. I did somewhere around 5% by weight. Don't know what concentration the commercial finishers use.
|