pure acid

[bryan93644]

i was looking at a great anodizing site, http://www.focuser.com/atm/anodize/anodize99.html, with which i am not afilliated but please don't sue me for postiong that- and it seems he is using pure acid, not 1/3 like i have heard, not exactly 16.5% as someone told me, does it really matter what ration you use, and why? thank you!

[Fibergeek]

I have seen that website, very well done.

You misread his directions; he avocates a 1:1 ratio of battery acid to water, he doesn't say if the ratio is by weight or volume, and that makes a big difference.

The anodizing process will tolerate large differences in acid concentration, with varying degrees of success of course. If you actually used "pure acid" meaning concentrated sulfuric acid, the dissolution rate would be sky high, and I doubt that you would form any layer at all. If you used no acid at all, there would nothing to supply the oxygen needed in the chemical reaction that forms aluminum oxide (oxide implies oxygen) which is what anodize is. No, the water can't supply the necessary oxygen. Again, you would form no layer at all. There are chemicals that will supply the oxygen other than sulfuric acid, few work as well, and all are much more expensive.

BTW, the assumptions about battery charger output on that website are dead wrong.

If you want to know how to do it right, and you want to know the "why" download and read the new LCD process instructions. Unlike other directions you have seen, these explain the "why" in good detail in the reference paper at the back of the document.

[mcaswell]

The site you refer to is 'affilliated' with us, however he is currently using an old method.

I am hoping he will update his site in due course.

You would be well advised to use the LCD method, it is a LOT less tempremental, and WE can offer better technical support.