DIY anodizing thread.

[71T Targa]

I'd like to try anodizing and have been searching the web for examples. My kid just picked up a mini-lathe and is 'modding' yoyo's and want's to anodize the parts after, and I'd like to do a lower...

Here is the general process I found that seems to lay it out in simple terms.

Now for my immediate questions:
Is a gallon distilled water jug a suitable Polyethylene container for the Sulfuric acid?
What can be reused and what needs to be new each time? ie. Can the acid bath be reused? How about the AL wire? Or are these one and done
In some instructions I see the use of a lead plate, and not an Aluminum foil loop. Any idea why or what the differences would be?
Can multiple parts be done at the same time? If so, what is the limitation?

Then the dye. I see people using Rit, is that 'good enough'? And can it be reused? Once. twice, 10 times?

Any advice, links, or YouTube's would be appreciated.

[flatbutt]

Generally yes but I'd make sure it isn't a very thin walled vessel.

[gatorbud]

I usually annodize titanium so i cannot speak to alot of your questions.

However in respect to your coil it has to do with surface area so imho its 6 of one and half dozen of the other. I use a plate with a heavy plastic mesh over as to prevent grounding my peice to the plate and it works fine. You definatly want to isolate the annode from the cathode if you can.

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[71T Targa]

Thanks Flatbutt!

If I'm understanding the process correctly, the anodizing process needs to be kept cool, and the dyeing solution warm?

Originally Posted by gatorbud

I usually annodize titanium so i cannot speak to alot of your questions.

However in respect to your coil it has to do with surface area so imho its 6 of one and half dozen of the other. I use a plate with a heavy plastic mesh over as to prevent grounding my peice to the plate and it works fine. You definatly want to isolate the annode from the cathode if you can.

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Do you reuse the plate? If so, how many cycles?

[gatorbud]

With titanium its resuable indefinitely wouldent see where aluminum would be diffrent.

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[Pazuzu]

Aluminum wire (to hold the part) is a one time thing, because it gets anodized as well and looses it's conductivity.


If you are meticulously clean, and only allow pure aluminum or titanium into the baths, then they last for a very long time. Contaminate them with anything, and they'll leave marks on all of your stuff.

Anodizing creates heat, you need it cool, but as long as the tank is large enough it's not a big deal. Dying is done warm (90-150 F depending on the color). Sealing is done at boiling temps.

Dye can be used until it dries up, you're actually putting dye particles into the anodizing structure, so after hundreds of runs it will be gone...

Constant amp source, not constant volt source.

Easiest way to clean a part is sandblasting then pure soap and water, but it will be matte after that. If you want shiny, you need to clean it chemically by hand (rounds of acetone, high grade alcohol, pure soap, distilled water). Don't de-smut it if you want it to be shiny.

[71T Targa]

Originally Posted by Pazuzu

Aluminum wire (to hold the part) is a one time thing, because it gets anodized as well and looses it's conductivity.


If you are meticulously clean, and only allow pure aluminum or titanium into the baths, then they last for a very long time. Contaminate them with anything, and they'll leave marks on all of your stuff.

Anodizing creates heat, you need it cool, but as long as the tank is large enough it's not a big deal. Dying is done warm (90-150 F depending on the color). Sealing is done at boiling temps.

Dye can be used until it dries up, you're actually putting dye particles into the anodizing structure, so after hundreds of runs it will be gone...

Constant amp source, not constant volt source.

Easiest way to clean a part is sandblasting then pure soap and water, but it will be matte after that. If you want shiny, you need to clean it chemically by hand (rounds of acetone, high grade alcohol, pure soap, distilled water). Don't de-smut it if you want it to be shiny.

This is great, thank you.

I think my old manual battery charger has a setting for 2A, 15A, and 100A

[Pazuzu]

Oh, Rit dye is fine if it's something that you're just making for yourself, and you don't really care exactly what the color is.
If you're doing some type of production, or a few runs where everything needs to match exactly, then spring for some good anodizing dye, and you'll get consistent results.

[Arizona_928]

I would not use water jugs for any acid storage. Lid securing, and the fact that milk jugs tend to break when dropped/sensitive to UV.

Pool acid/muraic /hcl can be bought in gallon sizes and a little thicker platic and securing lid. Understand that h2so4 is different than hcl. I would use a thicker plastic. Water jug is like a thin water bottle, I would aim for Gatorade bottle thickness (you might be able to use one. I don't use it in my lab and don't recommend). They sell individual squeeze bottles for this, or glassware storage... How much chemical are we talking about? It's kinda rare to see macro chem at a home level without catching the radar of big brother. Or at least I did when I ordered a bunch of chemical to phosphate

You can re-use electrolyte. There should be a calculation. I'll have to check my analytical chem text.

[71T Targa]

Thanks Kid, you make great points. Something sturdier than a milk/water jug will be better.

The 'bath' only needs to be enough to cover a yoyo or lower, so not a lot of acid. Can Muraic acid be used in place of Sulfuric acid? Some of the older videos I've found were using PH minus.

I found this that helped explain a lot of what's going on. I thought it was great anyway...

[MBAtarga]

I’ve found that windshield washer fluid is cheap and normally comes in rather thick sturdy gallon containers. You could look for a few of them for fluid storage.

[Arizona_928]

No hcl will 'eat' the aluminum and produce hydrogen gas.
Stick with h2so4, which you can rob from lead acid batteries, or try to buy local as "battery acid".
Online usually requires hazmat fee, and the chem suppliers are highway robbery imho for small quantities.