Anodising

[MartinParticipant @martin]

My second attempt at anodising 12x66x3mm strip unknown grade (I assume it came from aluminium sheet used in small aluminium boat manufacturing).

The first one I did, I had problems with maintaining a suitable connection, I used titanium strips milled from sheeting, I simply bent the strip into a hook and dangled it into the acid bath, in turn clamping the other end of the strip to an aluminium angle which spanned the plastic container. This all proved to be too flexible and failed to provide a suitable connection.

The second attempt I squeezed the hook tight with pliers (see the marks above the hole) this worked immediately and bubbles started to appear as soon as switched the power on.

The colour was "Parker" blue diluted 1:1 with distilled water, immersed for only 5 mins then sealed over simmering distilled water for a further 5mins then left in the water for a further 15mins.

Futher improvements to the fastening will need to be made prior to my next episode, any suggestion to this would be greatly appreciated.

Martin

[Ramon WilsonParticipant @ramonwilson3]

Congratulations Martin, that looks very good – nothing like some success to lift the spirits – you're certainly on the right road now.

Re the fastening of the part to the hanger – so far all I have done is taper the end of the hangers – a very slow taper that is – and just gently pushed these into suitable holes in the component to give a tightish fit. This has proved more than sufficient on such parts that have a hole. On the cylinder heads I bent the hanger back on itself in a 'U' to a spring fit inside the cylinder head. This does leave very slight noticeable marks at the contact points once coloured but as these are hidden on assembly they are of no concern. By just hanging the part lightly on the hanger the surface will anodise beneath the point of contact reducing the electrical condutivity as it does so.

Writing inks have certainly given me the best results so far and I have since bought some other but as yet untried colours. Tha's certainly a lovely blue.

I still think you could protect the male thread from anodising by wrapping with PTFE tape – now you are set up why not try that on a test piece – I would be reluctant to 'lap' the thread by bringing the two parts together – they may bind irretrievably – but lapping the male with a small piece of hard wood with the paste embedded into the end grain works well if used like a thread chaser – letting the thread gradually form itself into the grain as it runs down the thread. I have used this method on many occasions when a chaser isn't available to polish a thread for that final fit.

 

Hope this is of use – Ramon

 

PS – I see the posts are obscurred by the adverts again – nothings changed much there then.

Edited By Ramon Wilson on 26/12/2012 16:08:19

Edited By Ramon Wilson on 26/12/2012 16:09:27

[noel shelleyParticipant @noelshelley55608]

hi all, a new boy here but as regards acid strength, "normal" industrial strenght is 95% or so. To arrive at a consistent and repeatable bath strength the use of a suitable hydrometer may prove handy, depending on strenght or sg an ordiary battery hydrometer may work ?

Noel

[MartinParticipant @martin]

Thanks Ramon,

I will let you know how I proceed.

We have high temperatures for the next few days (41C) so I may wait until next week, or I will have to chill the acid bath with frozen water bottles, not the ideal!!!!!!

Martin

[MartinParticipant @martin]

Gents,

I have just successfully anodised a small part using Parker Black Ink.

Approximately 20 mins. in acid bath (20%) @ 15v amps @ around 0.4-0.5

10 mins in 1:1 ink/distilled water.

5 mins. in steam and a further 10-15 mins in simmering distilled water.

I also had success on another part using thread tape to protect the thread from anodising.

The following pictures are an indication of the colour, in reality the finish is much better than the photo's show.

Martin

[Ramon WilsonParticipant @ramonwilson3]

Nice work Martin, very nice Black.

For some reason black ano dye is more expensive than the rest – good to hear the ink works as well as the other colours – all I need to do now is find a nice bright green.

Pleased to hear the thread tape idea worked too.

Your time is much shorter too – so far I've run for 40 mins but will try reducing it next time.

Did you get any leaching of colour after the steam when simmering?

Regards – Ramon

[MartinParticipant @martin]

Ramon,

Maybe the ambient temperature has something to do with the time factor, we are currently having mid 30deg C days.

I haven't noticed any leaching, but I held the part in the steam continually turning it, as opposed to just hanging it from above and allowing the condensation to drip from the lowest point. Not sure how I will go when I have more than two parts, maybe the wife, next door neighbour and the guy from over the road can lend a (two) hands?

Next job is the centering microscope.

Martin

[Ramon WilsonParticipant @ramonwilson3]

Hi Martin – Hmm! that mighty have something to do with it

The turning 'technique' is how I've been dealing with it since the Eta head leached some. I've found where possible using two support wires help in that respect to a degree but of course there have to be holes for them to pass through.

Don't forget to put some pics up of all your finished parts.

Regards – Ramon

[MartinParticipant @martin]

Ramon,

I finally finished the Centering Microscope.

To protect the threads I used electrical tape wrapped tightly onto both internal and external threads, it was quite tricky and not quite 100% effective, as the acid effected the adhesive and ingressed under the tape, especially the internal threads where I could not apply as much pressure as the external threads. In spite of this I finished up without any problems with mating threads being too tight.

To colour the anodising I used "Parker" black ink 1:1 with distilled water. With the exception of the tube section all the aluminium parts were made from the same piece of stock bar, and all took on the same colour and shade, however the tube finished up with a slight blue tinge, I'm assuming this is due to the difference in grade of aluminium as it was quite difficult to machine compared to the bar stock. This can be seen quite clearly in the second photo.

As this is really my first attempt at doing a finish component and not just a test piece, I'm very pleased with how this has turned out.

Martin

[Steve Talbot 1Participant @stevetalbot1]

Congratulations Martin your microscope is a credit to you.

I know Ramon and other are using Titanium 'hangers'. Does the Titanium have to be 100% purity? I notice on ebay that Titanium wire is available but is only 97% pure.

Steve T

PS Has anyone used printer inks, and if so with what results.

Edited By Steve Talbot 1 on 11/02/2013 17:57:04

[BWParticipant @bw]

Posted by David Clark 1 on 30/03/2010 16:43:36:

Hi There

Check out the digital free copy of Model Engineers' Workshop.

It has a good article on anodising.

regards david

 

Where do I find this please ?

[dean clarke 2Participant @deanclarke2]

Hi bill ,if you heed help with anodizing read my supercharged v12 thread in this website or also ramons anodizing thread on this web site. any questions pm me.

cheers

Dean

[JasonBModerator @jasonb]

Bill I think it is no longer on the site as that was quite a while ago. It I remember rightly it was the magazine with Ramon's article in it. Now only available to digital subscribers.

[Neil WyattModerator @neilwyatt]

There's a link to a sample copy available on the 'magazines' page for those without a digital subscription, but as I have one it doesn't show on my account.

[Dave MartinParticipant @davemartin29320]

Bill – you may also find some useful info in this thread

Dave

Edited By Dave Martin on 27/11/2016 11:46:08

[BWParticipant @bw]

Thanks for the links will have a look and then have a go.

Could somebody please post a link to the freebie on the "Magazines Page" that Neil mentions. I have found heaps of reprinted articles but no entire magazine – must be looking with my eyes shut.

Bill

[Neil WyattModerator @neilwyatt]

Click 'magazines' on the green bar at the top of the page. Or here:

http://www.model-engineer.co.uk/members/DigitalEditions/

[Steve Talbot 1Participant @stevetalbot1]

Hi,

I notice Ramon Wilson used to post on this forum but I have not seen any posts from him for a while. Anyone know if he has moved to another forum?

I am trying to obtain copies of his updated plans for the ED Racer (I have the one in MEW) anyone know of a source?

I am also trying to obtain plans for a Boll Aero 4.4 engine if anyone can point me in the right direction.

Seasons Greetings to everyone.

Steve T

[JasonBModerator @jasonb]

Ramon is having a bit of a rest from model engineering and sticking to his plastic modeling. He has recently completed and sailed his "Wide Awake" steam launch. Pops his head up on Model Engine Maker forum occasionally which is where he has been posting his engineering projects for the last couple of years.

Were his ED racers not in ME, I think it was only teh anodising that was in MEW.

J

[KWILParticipant @kwil]

Martin,

You are quite correct that the "colour" changes with the grade of the aluminium, if you want it exactly the same, it must be the same material.

Commercial anodisers have this problem as well.

[Author]

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