Here's the FAQ continuation from my original tutorial that I promised... Firstly, for those of you who haven't read my 22 Jan post here, I really, really, recommend you to google "DIY anodizing"! There are better guides out there, by people who do this for a living! Also, cheers to Rudan at happymtb.org, I really liked what you did there!
Q: How much current should I use? / What electrical source can I use?
0.03A per square inch, or 0.0046A per square cm of exposed surface area. 9V battery cells will work. The electrical source I used was an AC-DC rectifier - you can get one from a hardware store, but it's a costly expense if you're only using it to experiment with anodizing. 2wheels explained here how you can put them together, and use 1.5V cells for lower step-ups; and that you can tear apart 9V cells for the same effect:
Q: How much current should I use? / What electrical source can I use?
0.03A per square inch, or 0.0046A per square cm of exposed surface area. 9V battery cells will work. The electrical source I used was an AC-DC rectifier - you can get one from a hardware store, but it's a costly expense if you're only using it to experiment with anodizing. 2wheels explained here how you can put them together, and use 1.5V cells for lower step-ups; and that you can tear apart 9V cells for the same effect:
Hacking a 9V cell.The effect of current is to speed up the process, i.e. increase the rate of evolution of oxygen at the anode. Practically, it's been found that it isn't necessary to increase the current.
Q: The color doesn't look good / the results are inconsistent. How do I improve the technique?
Using coke is a last resort. TSP and battery acid are better. You probably live in a country where these can be bought. I worked out that battery acid should come in 4.2M concentration - and you can use a 1:1 volume of distilled water to acid. If you have the acid in other concentrations, you should "Google for advice".
And this is a trick I came up with on my own: you can heat up the coke in the microwave oven. As I had explained in that post, the electrolysis of water is an endothermic process. By Le-Chatelier's principle, the forward reaction is favored under higher temperature conditions such as to counteract the stress by suppressing the extra heat. So you're speeding up the release of oxygen, without increasing the current. Simple trick isn't it?
Q: The color doesn't look good / the results are inconsistent. How do I improve the technique?
Using coke is a last resort. TSP and battery acid are better. You probably live in a country where these can be bought. I worked out that battery acid should come in 4.2M concentration - and you can use a 1:1 volume of distilled water to acid. If you have the acid in other concentrations, you should "Google for advice".
And this is a trick I came up with on my own: you can heat up the coke in the microwave oven. As I had explained in that post, the electrolysis of water is an endothermic process. By Le-Chatelier's principle, the forward reaction is favored under higher temperature conditions such as to counteract the stress by suppressing the extra heat. So you're speeding up the release of oxygen, without increasing the current. Simple trick isn't it?
The smell of boiled coke is kinda nauseating.
My sister told me, "Ew, that's sick." I agreed.Anyway, note how much faster it's bubbling.
Q: Can I use pepsi? (updated)
See the link to Rudan's work right above in the 1st paragraph: yes.
Q: How do I anodize aluminium?
You can use the same method. Only, after you're done, rinse and dry the piece you are working on, then soak it in a warm anodizing dye. Anodizing dyes aren't cheap, which is why I discourage anodizing aluminium on your own. It can cost as little as $5 per piece from a professional service.
(Warm = 38-60 degrees celsius.) theremery wrote a good post around here on using clothing dye for the job.
Q: Can I also get [color, e.g. red/black/white] from anodizing?
No, if you can't find it on the color-voltage spectrum on my previous post. It's been explained that you'll be rich if you can figure out a way to anodize titanium to a black or white color. Think about it, a classy fountain pen fashioned from titanium, with an anodized black coat that doesn't display wear. (Note: This has something to do with the previous post.)
I hope this FAQ solves the common problems. You can always leave a post on the starbike thread/email me if you have a question.
No comments:
Post a Comment