Thread: DIY anodising and a question

1. Yes, remembering that you may get filings or emery on your ways so you need to watch for that. There are safety implications too. When filing you shouldn't have your arm across the headstock. For emery, approved practice is not to hold it against the part with your fingers (in case it grabs) but use a backing board.
2. Yes, provided you are happy with the chemicals needed. Anodizing can make dimensions change, so for a one off you may be better going to a commercial outlet and taking their advice.

Michael

Shouldn't be a problem DIY anodising aluminium, you'll need a rectifier, various containers of different solutions, cleaners, picklers etc.
www.caswellplating.com.au/, can supply all the bits required,but for a one off job, you might be better to take it and have it done.
Kryn

The part I would like anodised is approx 50mm dia x 20mm thick.

Would anyone know how much this would cost? If more than I can justify, is there some other process that will give me a satin black finish, apart from satin paint?

Ken

This bloke does a pretty good 3 part anodising how to on YouTube:

Part 1: http://www.youtube.com/watch?v=GccTVfMiIIo

There's another one by a bloke who does a good how to on making a compressor from a fridge compressor. He has the best voice but I couldn't find doing a quick search, it too is worth a watch.
Regarding using emery on the lathe, tear a strip about 12" long, hold each end between your thum and finger and use it kind of like a file, this gives you an even finish and will slip from you fingers if it grabs.
Cheers,
Greg.

Originally Posted by neksmerj

The part I would like anodised is approx 50mm dia x 20mm thick.

Would anyone know how much this would cost? If more than I can justify, is there some other process that will give me a satin black finish, apart from satin paint?

Ken

Of all colors, black just happens to be the most difficult to anodize. If not done perfectly it looks mottled and wrong. And what you are after for lens/camera parts is possibly a very thick and hard wearing type of anodizing called "hard anodizing" where the bath has to be chilled and higher currents are used.

For a one off, an alternative could be to simply paint the part with an aerosol can. If it wears over time, you simply respray it.

A particularly well suited paint for such camera parts could be black "wrinkle finish", but it is hard to find in a rattle can nowdays. It gives that antique finish, and is hard wearing too. Here a supplier: http://www.ebay.com.au/itm/VHT-BLACK...item4d2d3190d8

Another alternative is to make the part in Brass, it can be blacked chemically (like with Birchwood Casey Brass Black)

Cant help with the anodizing as I only get steel blackened ,professionally very cheaply.

In regards to your .02 be very careful with the file or emery as it will only take a lick before its undersize.

For what you are doing don't even worry about grit getting on your bed,you would be flat out trying to see it.

Originally Posted by cba_melbourne

Another alternative is to make the part in Brass, it can be blacked chemically (like with Birchwood Casey Brass Black)

Disappointingly, not as black as you might hope for Chris. Charcoal maybe ........... https://www.woodworkforums.com/showth...11#post1813411

Black Contact is another way of putting a black surface on aluminium, without all the fiddle of etch priming it - reasonably durable, too.

Originally Posted by Anorak Bob

Disappointingly, not as black as you might hope for Chris. Charcoal maybe ........... https://www.woodworkforums.com/showth...11#post1813411

Bob,

there are usually two distinct sides to parts used for optical devices. Two very different surface finish requirements.

- There is one side, like the inside of a camera lens, that must absolutely not reflect light. Any other consideration is completely secondary to this requirement. Any internal reflection degrades the lens quality and its true value.
- The other side, like the outside in the case of a camera lens, has often to please the eye and be durable and provide a good grip to our hands. Any imperfection degrades its perceived value.

Unfortunately, the two requirements are mutually exlusive. I have worked 11 years of my life with mainly optical machines, many using some of the most expensive lenses available. There is no finish that looks good, is durable, and is completely non-reflective to visible light. My experience is that non refective surface finishes are matte and quite fragile. Then again, nobody ever touches the inside surfaces of a camera lens or a microscope or the like. It is safe to use a soft matt paint. And noone never ever looks at these surfaces, so even in an extremely expensive camera lens (think $10k+) it is perfectly ok to use a brush to apply anti reflective paint where it is needed. This is in total contrast to the outside, where the very slightest blemish would be totally unacceptable even on a very much lower quality $200 lens.

What I want to say is simply, that for optical parts it is often best to use two completely different finishes for "inside" and "outside".

Black Chrome
but you might find it difficult to find someone who does it

Vantablack -

http://en.wikipedia.org/wiki/Vantablack

Every single photo of it looks photoshopped; it's just too black.

Originally Posted by Master Splinter

Vantablack -

http://en.wikipedia.org/wiki/Vantablack

Every single photo of it looks photoshopped; it's just too black.

But where can you get these modern nanoparticles from? How do you apply them?

Instead, common soot has been used in the past. Soot are carbon particles resulting from incomplete combustion. They are nanoparticles actually (are not diesel engine particulate filters there to trap these nanoparticles?), just probably not as pure or not as healthy as this Vantablack? The flame of a storm lamp will coat a metal surface with deep black soot. The thicker the coat, the less light the surface reflects. An Acetylene flame (without the Oxygen) also generates plenty of sooth. It is not a very durable coating though, it can simply be wiped or washed off. But inside an optical tube it may be fine. Maybe not so in closed item such as a camera lens, because of the gassing out of particles that over time could cloud lens surfaces. A heavily soot coated surface is indeed very black....

Originally Posted by cba_melbourne

Bob,

there are usually two distinct sides to parts used for optical devices. Two very different surface finish requirements.

- There is one side, like the inside of a camera lens, that must absolutely not reflect light. Any other consideration is completely secondary to this requirement. Any internal reflection degrades the lens quality and its true value.
- The other side, like the outside in the case of a camera lens, has often to please the eye and be durable and provide a good grip to our hands. Any imperfection degrades its perceived value.

Unfortunately, the two requirements are mutually exlusive. I have worked 11 years of my life with mainly optical machines, many using some of the most expensive lenses available. There is no finish that looks good, is durable, and is completely non-reflective to visible light. My experience is that non refective surface finishes are matte and quite fragile. Then again, nobody ever touches the inside surfaces of a camera lens or a microscope or the like. It is safe to use a soft matt paint. And noone never ever looks at these surfaces, so even in an extremely expensive camera lens (think $10k+) it is perfectly ok to use a brush to apply anti reflective paint where it is needed. This is in total contrast to the outside, where the very slightest blemish would be totally unacceptable even on a very much lower quality $200 lens.

What I want to say is simply, that for optical parts it is often best to use two completely different finishes for "inside" and "outside".

Thank you Chris.

What has always intrigued me is the application of the finishes found on optical products. How are they so perfectly applied?

Bob.

Originally Posted by Anorak Bob

Thank you Chris.

What has always intrigued me is the application of the finishes found on optical products. How are they so perfectly applied?

Bob.

Bob, I would say that is every makers own secret. Some optical products are renowned and sought after not only for their optical properties, but also for their particular type of exterior finish. I suspect that the majority of optical consumer product like cameras and binoculars etc are bought for look and feel and prestige, rather than for pure optical performance. Whereas professional or industrial optical products are bought on performance vs cost ratio, and mechanical durability. The external appearance being almost irrelevant.