Anodizing Titanium question

[billyO]

Hello all.  I recently forged a couple of bowls out of titanium, and am having a bit of difficulty electro-anodizing them for the colors.  I practiced on some scraps that didn't see the heat of the forge and was successful, but am not having luck on the forged pieces.  I used my angle grinder to wire-brush all the scale off the pieces, but there must still be some oxidation or something else preventing the colors from showing.  I then used an an grinding disc on the flat bottom and this worked, but there is no way I'll be able to get into all the nooks of the bowl with it.  I'm hoping someone has a liquid I can soak the pieces in to remove whatever is preventing the anodizing (I'm thinking about how I soak a damascus billet in vinegar overnight to remove the forge scale before cutting/re-stacking/and welding again).

Thanks.

[Frosty]

Okay, wire brushing is a NO NO! The only mechanical cleaning it's okay to do is grinding and or sanding. YOu need to "Electro polish" Ti to clean it for coloring.

Warm up your GoogleFu and search, "Reactive metals" there are a number of fora and groups making Ti and other reactive metal jewelry. It's a hot and marketable craft.

Coloring Ti is nothing like patination of iron and copper alloys It's WAY different  than anodizing Al. Though the process is similar it's way different than anodizing. Calling coloring reactive metals Anodizing is a common mistake.

Frosty The Lucky.

 

[billyO]

Thanks Frosty!  Re: wire brushing - That was my conclusion.  It seems to me that it has left a film on it....I'll do the google search as suggested.

Coloring the non-forged scraps was relatively easy using various numbers of 9V batteries in series and TSP. 

 

 

Oy....after doing a bit of reading looks like I need to see how much it'll cost to get these electropolished....or spend a lot of time sanding, I suppose.

[BIGGUNDOCTOR]

You can also do it by heating them and letting the oxides form. Try that with some scraps.

[billyO]

11 hours ago, BIGGUNDOCTOR said:

You can also do it by heating them and letting the oxides form. Try that with some scraps.

Thanks.  I've already experimented, and although it works to a point, it doesn't give the control or variety of colors that anodizing does.

 

14 hours ago, Frosty said:

Calling coloring reactive metals Anodizing is a common mistake.

It was explained to me that it's called anodizing because the titanium is attached to the (+) terminal of the battery.  (It's my understanding that in an electrolytic cell, the (+) side is the anode, whereas in a voltaic cell it would be the cathode)

 

Here's a link to a quick instructional on the process: http://www.candlepowerforums.com/vb/showthread.php?395316-A-guide-to-Anodize-Titanium-on-a-budget

[billyO]

After a couple hours grinding and sanding, here's what the exterior of the 1st bowl looks like.  I used a q-tip as a paintbrush on the (-) pole. and started with the high voltage and worked my way down.  It's a heck of a lot of fun watching the colors appear, especially when 'painting' over prior colors and having them not change.

Now I need to decide what design for the next 2 and if I should do the interior of the bowls...

[billyO]

Here's the 2nd one...

I really like watching the colors form, I may have to do more.....

 

 

[Frosty]

On 8/23/2019 at 6:40 AM, billyO said:

t was explained to me that it's called anodizing because the titanium is attached to the (+) terminal of the battery.  (It's my understanding that in an electrolytic cell, the (+) side is the anode, whereas in a voltaic cell it would be the cathode)

Yeah but anodizing is only part of the process, I only brought it up as a point of interest, it' become a common term. Isn't the starter in your vehicle anodized too? Seriously anything that's connected to a positive terminal is anodized. It's a specific term that's fallen into common use to describe complex operations, sort of like lumping all blacksmithing processes and calling it "Heating."

I'm not saying you or anybody should confuse things it IS really just a topic of conversation. Honest. 

Frosty The Lucky.

 

[billyO]

Got it, Frosty, thanks.  I was just commenting on my understanding (which is very limited in this area of metal working, as was made apparent by my use of the wire brush initially) and looking to open up a discussion to increase my knowledge. (I didn't think you were being argumentative, btw) 

[Frosty]

I tend to wax pedantic sometimes and I think I'm often explaining myself rather than current . . . stuff. (lost the word. I think it's all those wrinkles in my brain, makes it too easy for words to hide.)

 Jer

[billyO]

Hello all.  Here are the final products.  Fun learning experience and I may have to do more in the future.

\

[SFC Snuffy]

Those are beautiful. Well done! How difficult were they to form? Raised or sunk?

[billyO]

Hi Snuffy.  Thanks!

I used a friend's 30-ton press with a 5" diameter ram and sunk them into rings made from 2" round.  It was easy once we figured out how fast we needed to move and how deep to sink them before cracking.  The titanium lost heat really fast just walking from the forge to the press and it wasn't until I preheated both the ram and ring to a red heat before dishing did we have success.  Fortunately it only took 2 failures to learn that.