Anodising in Black

[bulgin]

Hi

I regularly anodise small components. Sometimes blue (for which I have professional tint) sometimes in 'natural' and recently in simulated 'gold'.

If there are diy anodisers on the forum, I've had very good results with simulated gold by using Moir's Egg Yellow food colouring - mixed to have a ph of 5.5.

I have good equipment and chemicals - some bought from a local anodising chemical and equipment supplier and some built by myself. So, job preparation before anodising is not an issue.

Right now, I am required to supply a small, 5mm thick spacer for a phono cartridge, anodised black, which I have never done. Well, making the spacer was no problem.

I checked the various anodising sites and the product Dylon Ebony Black Multipurpose Dye came up.

I had bought 2 containers long before and used one of these mixed in to 1 litre of deionised water and then adjusted the ph to 5.5 using chemicals I have here. The mix was prepared cold and after the anodising process, the temperature of the tint mix was raised to 55 degrees. Before immersion, I kept a small container of the tint mix separately at room temperature for pre-colouring while the alu oxide pores were still open. After that, I immersed the spacer in the hot tint mix for about 1/2 hour - which is much longer than for the other colours I use.

My best results were a kind of bronze colour. Not black enough.

After more web googling, I came across a comment somewhere of using 4X the amount of Dylon for a denser black.

Following the same procedures as described, I tried the new mix and the results were almost the same, if not worse.

This morning, I checked Dylon's own website and saw for a denser black (for clothes dyeing), they add their colour Tangerine to the black.

I might add that the amperes used was correct ( the two small objects drew about 0.3amperes @ 16V and the anodising layer was even and took quite a while to strip off again with boiling phosphoric acid.

Other than ordering 'professional' black anodising tint, has anyone here at diyaudio used Dylon black with good results for black anodising?

Much obliged for some advice or feedback.

bulgin

[OzMikeH]

I have no experience with anodizing, but I used to do a lot of professional chassis work.

We made a point of NOT using black permanent markers for any marking out because it was impossible to remove all traces of it. there was always a ghost left no matter how you cleaned it with whatever solvent. Red, green and blue markers were very easy to clean.

We had a selection of black markers with a high pigment content we used to use for touching up damage on the black anodized parts.

If all else fails you can break a black marker in half and "paint" it with the wad of felt from inside the marker.

you might be able to extract the fluid from a whiteboard or permanent marker and use that.

sorry I couldn't be of more assistance.

[bulgin]

Hi Mike

Thanks for the kind reply. If the job was for myself, I'd do the black marker thing. Your tip definitely works when re-touching previously black anodised faceplates, for example. I've added a refinement to this when I use them for such an application. Since black markers show up shiny against matte black, I usually apply a few times and let dry in between. I then take a cloth and give the spot a few wipes, which goes matter black. Almost impossible to detect afterwards.

I guess I'll have to bite the bullet and mill the thing in either ebonite or african blackwood. Or go and buy the correct anodising black

I've stripped the object again last night and re-anodised but not sealed it yet.

I'm giving it one more shot with Parker black ink.

Cheers

bulgin

[Shaun]

Bulgin

Perhaps not for your immediate project, but it might be worth experimenting with photocopier toner. Might entail heating of the part... just a thought.

[Hotsauce]

As a gunsmith, I often faced similar finish issues.

http://lwww.lauerweaponry.com/duraco...l&Category=229

This is a very durable catalyzed finish that any hobiest can apply.

Very similar to factory HK finish.

John C.

[MJL21193]

How about powered fabric dye?

[bulgin]

Hello All

Thanks once more for all your kind views and replies. I'm running out of time on this job which also involve another item which goes with the spacer.

The photocopier toner is worth a try if it can dissolve in deionised water and if the ph can be adjusted to 5.5. As it is, I do have some toner cartridges for a copier I don't have any more.

Anyway, I had an option to make it from african blackwood but due to the slots I decided to use ebonite to avoid possible cracking when the cart gets screwed down.

I will look again at the gunsmithing black or bite the bullet and buy professional anodising tint in black.

Cheers

bulgin