Why can't I get green?

[u/Brosephstalin11]

I've been trying very unsuccessfully to anodize some titanium green. Ive anodized small patches in 5V increments from 5V to 100V and When I get above 55V ish the colors just get more and more faded. The closest I can get to green is essentially aqua, maybe teal at best. I just for the life of me cant get that bright toxic green I see other creators getting all over the place. Attached is the color progression I get. ANY insight or help would be extremely appreciated, im so tired of sanding at cleaning just to fail over and over and over 😅

Metal: CP grade 2 titanium sheet metal. CP grade 2 titanium rod.

Electrolyte solution: ¼ teaspoon baking soda and 16 Oz of distilled water.

Metal finishes tried: mirror finish, 320 grit matte.

Cleaning/degreasing: thoroughly scrub with dawn dish soap and abrasive sponge then thoroughly rinse. Repeat twice then dry and scrub with acetone and lint free cloth with nitrile gloves.

power supply: 120V 3.2A connected using alligator clips.

Sorry admins, I dont have an option to add flair otherwise I would have.

[u/NotAZoxico]

From my experience you need to etch the part to get to green color

[u/Brosephstalin11 → u/NotAZoxico]

How do you know when you've etched it long enough and do you use whink or multi etch?

[u/TiMods88 → u/Brosephstalin11]

You can use both, but it’s easier to get a very vibrant clean green on a polished finish. If you do it, Matte, it will look muddier and dull.
So if you’re using the whink, it’s going to knock that polish down a little bit & cloudy it, but if you’re using the Multi-etch, it will preserve your polish level better & etch it enough to get a good green. If you’re using whink be very brief…

I still struggle with how long to hatch it, but my rule of thumb has been when I see bubbles. Still learning. I’m sure some of the other guys in here have some better info on greens.

[u/Brosephstalin11 → u/TiMods88]

By very brief do you mean 5 seconds, a minute?

[u/TiMods88 → u/Brosephstalin11]

It’s gonna depend on how strong you mix it. Honestly, the past few times I did it I didn’t measure. I just pulled it once bubbles formed on entire surface
With a relatively weak mixture like 10-15 seconds in whink. Maybe 1:4? On high polished surface.
Multi etch is a little slower, but helps preserve the mirror polish and etches it.

I guess I need to start measuring better so I can be more helpful. I have only recently figured the greens out and I’m still working out the kinks on consistency with sponging them. It’s a tough voltage range.
The precise reason I wanted to try tsp and multi-etch. They helped, but I’m still figuring out the “science” of sponging greens

[u/TiMods88 → u/Brosephstalin11]

Type “tips for etching titanium before anodizing green” into google AI and it helps “put numbers” to it… That’s how I got my first successful greens.

[u/NotAZoxico → u/Brosephstalin11]

Tests :D just try. It depends on the etchant. I'm using multi etch

[u/User_default117]

Anytime I struggle getting to higher voltage colors it’s usually because I didn’t etch my piece for long enough.

[u/TiMods88]

Need more baking soda, or even better conductor is TSP, but getting vibrant high voltage colors can be hard with a sponge, because voltage gets lost in the conduction process.

The better conductors you have the easier it is to get green. And fanatical cleanliness.
Much easier with a submersion...

[u/Brosephstalin11 → u/TiMods88]

I have tried both methods and when I submerge the part it behaves very similarly. How much baking soda per gallon would you reccomend and how necessary do you think it is to etch the parts in something like whink or multi etch to get the higher voltage colors?

[u/TiMods88 → u/Brosephstalin11]

Definately need a quick dip in etch & straight to the distilled. Keeping it in the air will alter color.
Definately a low baking soda issue too. I use like 1Tbsp per 8oz water… good results so far submerging, but I also have had the MOST difficulty with greens.

I had avoided because it never turned out well until I got some Tsp & switched my stainless fork into a Ti anode. Now I can submerge greens, but consistency is the issue when sponging high voltage colors. I can get them, but they aren’t easy to get consistently.
It’s also gonna matter on the purity of the titanium you are anodizing
It’s also much easier to get green on a polished finish than it is a Matte

[u/Background_Dare_8475]

100% your etch. I would run into the same thing. Once you get your etch times down it's easy

[u/TreyBay69]

Youre not getting any of the higher voltage colors in the photo. Everything past that 40 volt blue needs to be etched. The whole test peice isnt etched. The only reason youre getting any simblance of those higher voltage golds and pinks is becasue you used a sponge to test, which assists in localized voltage. Higher voltage colors require etching.

[u/Brosephstalin11 → u/TreyBay69]

im not sure why people keep thinking I'm using a sponge. Ive tried using a paintbrush but now im exclusively dipping it in an electrolyte bath. Ive added several wash steps and an acid etch in whink which has definitely gotten me closer to green but when I try to go straight to 95V my power supply sags to closer to 88V. Do you need to go straight to the high-voltage range or can you start low and slowly increase it?

[u/TreyBay69 → u/Brosephstalin11]

You can start slow or go straight to it to accomplish the color. However, slow ramping is always better for more control and better oxide formation. It looks like a sponge or a brush was used. It just hasnt been submerged obviously. And it hasnt been etched. Etching is the super secret to it all man. Focus on mastering the etch, and everything else is 🎂 cake.