Etching Titanium Before Anodising... In the UK

[Samlack99]

Help!

I'm getting so frustrated finding a solution to this obstacle.

Little background first...

I make high-end, custom, gentlemen's folding knives.

Bolsters made of titanium are very popular, so is anodising those bolsters in pretty colours.

My anodising setup can be seen in the photo below:



Basically:

• DC power supply (0-120V)
• Cleaning fluids - To get rid of sticky finger marks etc.
• A big tub of electrolyte (distilled water and trisodium phosphate (TSP)) with a large plate of titanium to act as the cathode (negative)
• An ultrasonic cleaner - To clean the parts before anodising

My set up works fine for lower voltage anodising (see diagram below):



But at higher voltages my results are very patchy (See diagram below, not the vibrant green I was after):



Research has lead me to the conclusion that to get those vibrant high voltage colours, etching the titanium before anodising is the way.

And that's where my problem is because:

• Wink rust and stain remover
• Multietch
• Titan-etch

Are not available in the UK and can't be shipped to the UK.

There must be a solution to this "etch before anodising" situation. Or doesn't anyone in the UK use vibrant, high voltage, colours in their titanium work?

Please help, because this is driving me mad

Many thanks

Marcus

[josef1]

Ive got a feeling Hydrofluoric acid (HF) is used to etch Titanium but its proper proper nasty stuff. Sealed enclosure with extraction melts through skin and bone on contact type of nasty. I used to use it to break down Platinum investment. It is available in the UK not sure if you need to comply with anything to buy it .Before breaking bad you could buy it off amazon ! l But really if you do decide to try it make sure you do your homework on it first.

[Samlack99]

Ive got a feeling Hydrofluoric acid (HF) is used to etch Titanium but its proper proper nasty stuff. Sealed enclosure with extraction melts through skin and bone on contact type of nasty. I used to use it to break down Platinum investment. It is available in the UK not sure if you need to comply with anything to buy it .Before breaking bad you could buy it off amazon ! l But really if you do decide to try it make sure you do your homework on it first.

Thank you for your reply.

Based on what I've read (confirmed by what you've written) I'm very keen to avoid Hydrofluoric Acid at all costs. That's why I'm looking for an alternative, such as Multi-Etch and Titan-Etch...

Is there such a thing available in the UK?

[ps_bond]

Multi etch & Titan Etch are mostly sodium fluoride. So while it's "safer" while dry, as soon as it's in solution it's about as hazardous as HF. AND I've not found a sane way to dispose of the stuff in the UK.

Can't remember if it is covered by the EPP legislation too.

BTW - hi Marcus

[Dennis]

You will see here that vibrant colours Can be problematical: http://www.torontocycles.com/Titanium_Anodizing.html

Reactive Metals was one of the first companies to market anodising equipment for titanium/niobium. They are always helpful if you contact them: https://www.reactivemetals.com/ Dennis.

[Samlack99]

Hey Peter,

Hmm, looks like etching titanium might be a non starter then...

I'm wondering if I could use niobium or tantalum for bolsters instead of grade 5 titanium? How scratch resistant are these metals?

Trouble is I can't seem to find any niobium or tantalum in 4mm thick sheet (a quick google and eBay search turned up nothing).

Anybody know where I could buy small pieces of 4mm thick niobium or tantalum sheet from - preferably in the UK? When I say small pieces I'm talking 40mm X 30mm X 4mm or there about.

From what I've read niobium or tantalum gives good colours even without an etch.

Thanks for your help everyone on this.

[Samlack99]

You will see here that vibrant colours Can be problematical:

Reactive Metals was one of the first companies to market anodising equipment for titanium/niobium. They are always helpful if you contact them:

Thanks Dennis, wow, Black titanium... That'd be cool

[Ralph G]

the reason behind etching before anodizing is to remove the tenacious oxide layer that froms almost instantly on contact with oxygen. if you have no chemical means to remove the oxide layer you could try mechanical removal by e. g. sanding it in an oxygen free enviroment.thus there is no oxygen present for forming of a new layer of oxide. something like moving your anodizing equipment into a glove box filled with argon, sanding and anodizing it in there. certainly a nuisance to do it this way but if you have no alternatives... Look whats done in welding ti, its also done under argon and if done properly the weld seams come out silvery shiny and not heat colored/oxidized as they would when welded in air.