Tuesday, September 2, 2008

Anodising Aluminium at Home - Part 1




As I mentioned in an earlier posting I have become intrigued with the idea of anodising aluminium to use in a new line of jewellery. I am now embarking on that challenge and am inviting you to come on a journey with me through the process of setting up and hopefully being successful with this project.

I have done endless research on the process and have now began to source my supplies and set up the different stages needed. Before I go into my setting up process, I must make it very clear that this process involves working with dangerous acids. I can't emphasise enough that you must take extreme care when handling the products, wearing safety gear and working in a well ventilated area.

I had read that sourcing the chemicals may be a problem but I found they were readily available here in South Australia at Ace Chemicals. I bought 2.5 litres of Sulphuric Acid 98% Solution; 2.5 litres of Nitric Acid 70% and 5 kg Caustic Solda crystals (Sodium Hydroxide Pearl). Total cost of the chemicals $177.00, and the quantities I bought should last me some time.

The very first stage is to find a suitable area to work with acids. I cleared a bench under a carport outside where I have plenty of fresh air circulating, as it is an open space with no doors and only partially closed sides.
Next step is to wear suitable safety glasses and a respirator, both available from hardware stores. To complete the safety attire, a pair of strong rubber gloves and a heavy duty plastic apron. I'm still hunting for a suitable apron, for now I am wearing a heavy leather apron which nearly weighs me down to the ground.



Safety Glasses and Apron




Respirator




Gloves



I made all the 'baths' first, labelling each one. I'll firstly tell you how I prepared each bath, then I will describe each step of anodising in Part 2 which will then make the purpose of each bath clear. Keep in mind all my preparation is done on a reasonably small scale as it is for the purpose of small jewellery components only. If you were planning on anodising car parts, etc. it would need to be on a larger scale.
ALWAYS ADD THE ACID TO THE WATER IN ALL THE BATHS, NEVER THE WATER TO THE ACID
HAVE A BUCKET OF WATER WITH SODIUM BICARBONATE (BAKING SODA) MIXED IN. IF ANY SPILLS USE THIS MIXTURE TO MOP UP AS IT NEUTRALISES THE ACID.

Baking Soda



Degreaser - In a small jar with a screw top lid I have added a heavy duty detergent mixed in cold tap water.
Rinse Bath - In a 2 litre icecream container I have added a couple of inches of distilled water - now known as demineralised water and available from the hardware store or supermarket. You will need quite a lot of this, I bought a 4 litre container and found I needed another. If you can buy it in bulk, it would work out much cheaper, I'm paying about $6.00 for 4 litres, something I need to source in larger quantities.

Distilled Water



Caustic Bath - In a 2 litre icecream container I added 1 litre of water and then 160 grams of Caustic Soda.

Caustic Bath



Nitric Bath - In a 2 litre icecream container I poured in 1 litre of water and to that very carefully added 250ml of Nitric Acid.

Nitric Bath



Anodising Bath - In a reasonably large plastic container I add 3.5L of distilled water, then carefully poured in 700ml of Sulphuric Acid. I read the quantity to be Sulphuric Acid and distilled water 20% by volume.

Anodising Bath



I have made one run through of the process at this stage without success as I required some aluminium wire which I have finally sourced and am now waiting on delivery. Hopefully I will receive that soon and will then continue onto Part 2, showing the step by step process and how to set the anodizing bath up ready for connection to a battery charger for the electric current needed.


I'm enjoying my new challenge and am looking forward to a successful result. It's not an overly expensive project to set up, but the most time consuming and frustrating part is finding suppliers for all the items that are needed.







3 comments:

Conrad said...

I recently came across your blog and have been reading along. I thought I would leave my first comment. I don't know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.


Ruth

http://fendisite.com

Christine said...

Hi Lorraine, great to hear someone is exploring this at home anodizing process. Have you had any success in the dying process? would be good to hear as I am also exploring this. Christine

Glass and Splinters said...

Hi Christine,

After coming across so many problems I gave up for a while, but have just completed a 7 week anodising course which has been a huge help, and I am back anodising again.

I am more than happy to answer your questions if I am able, and it may be a good idea to publish any questions in a post so as to help others.

I haven't updated my blog in such a long time, this is probably a good time.