I was originally going to pose this as a question but I've since found the answer so I'm posting the link for anyone of a practical bent making their own photographic or astronomical kit.

WORKSHOP HOWTO, 10. ANODISING ALUMINIUM

This has been written by a practical guy who uses the process described.

(Note: please take care and follow all the sensible precautions he details. Strong acid and alkali solutions are not to be fooled about with.)

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By asking questions we sometimes get the wrong answers, from wrong answers we learn to ask the right questions.

Anodizing aluminum -- recipes are good, but it's a lot of effort to duplicate what commercial shops do routinely, and probably better than we can do at home (plus they don't have a learning curve). The problem with a shop is that they usually have a minimum fee or a setup fee.

If one can find a shop that is willing to take one's small parts and put them in with a larger batch, that would save a lot of effort.

I take my small anodizing jobs (telescope parts and the like) to a friend's local machine shop and they send them out with their much larger orders. Sometimes I get billed, sometimes not. But it's a lot easier than setting up your own factory.

Pete

NASA uses a lot of andozined aluminum, mainly black, clear and gold. Here's a nice site that shows the colors.

In the UK is it anodising or anodizing?

Beautiful parts...

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What brings us together is stronger than what pulls us apart

Thanks for the link, smart parts!

I normally spell ......ising words with the s but I belive a z is also acceptable. It's a bit like alluminium (UK) and aluminum (US) and I tend to take a Mid Atlantic view about it as long as the meaning is clear. (My MS Word spell check usually objects to the UK versions)

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By asking questions we sometimes get the wrong answers, from wrong answers we learn to ask the right questions.