Wet etch

[theoriginalspaceman]

I am trying to figure out the best way to put a small logo on 6Al-4V titanium. It is fairly detailed, and measures just under 1" x .25". I talked to a jewelry supplier here in Spokane and they have wet etch supplies, which sounds like a fairly common technique when making jewelry. The shop keeper explained the process to me as having a stamp made of the logo, then stamping the logo onto the part, after which the part is dropped into a chemical solution. The solution eats away the ink from the stamp and a small amount of metal under the stamp, leaving the etch. The problem was he didn't know whether it would work for titanium, as they specialize in more traditional metals common to jewelry making.

Has anyone tried this method? It sounds like it's too simple to be effective, but who knows.

Thanks,

Casey

 

[fumbler]

I was curious after reading this thread. Looking at the google results, it sounds like you have to use some pretty nasty chemicals to etch titanium. Honestly I'd be afraid to try just because of that. If I did anything, I might would try it with some phosphoric acid and hook it up to my etcher.

As far as the resist goes, I might not be understanding you correctly but typically you apply a resist (paint, stencil, toner, etc) and the acid etches everything but the resist. Wet etching shoukd work fine but almost everyone uses electro etching because its fast and you dont have to cover everything with a resist. There are plenty of threads on bladeforums about etching logos. You can read up on those. The only difference is you have to find an etchant suitable for titanium.

 

[Atlas Knife Company]

Let me google that for you:

Instructions

1 Make distilled water by boiling it and then measure 400 ml in a graduated cylinder. Add 20 ml of hydrofluoric acid to the water. Put the mixture into a container.
2 Rinse the graduated cylinder with the water mixture. Put the remaining distilled water in a second separate container. Dispose of the waste water according to your city's disposal methods for contaminated waste.
3 Add 20 ml of regular water to the distilled water mixture by measuring it with the cylinder. Rinse the graduated cylinder twice. Dispose of the waste water according to your city's disposal methods for contaminated waste.
4 Place a stencil on the titanium with steel tweezers where you want to etch it. Hold it in place with tape.
5 Wet the etcher head with the distilled water mixture and then put it on the stencil. Touch the ground wire of the etcher to the titanium for several seconds.

Read more: How to Etch Titanium | eHow.com http://www.ehow.com/how_8675014_etch-titanium.html#ixzz2KSfavT2o

Surely not the most scientific directions. Boiling water doesn't distill it. If anything, it would concentrate any contaminants. Secondly, hydrofluoric acid dissolves glass, so make sure to use a proper PP container. 5% hydroflouric acid, no glass. I'll dig up some hydroflouric acid on Monday and give it a shot. This stuff is considered a contact poison so be extra safe, wear a respirator, goggles, all the safety stuff you wouldn't normally bother with. 1-800-222-1222 is the poison control hotline in case you need it. Please research the heck out of hydrofluoric acid before you attempt this.

On second thought, this acid is so nasty that I recommend you do NOT do this yourself and instead settle for standard engraving.

 

[theoriginalspaceman]

Thanks Zaph - I had seen that article, but even following those directions making the etch involves using an electrochemical etcher (which after some more research is what I'll end up doing). I had thought, after talking with the jeweler supplier a few days ago, that perhaps there was a simple way to etch using only a stamp and some relatively safe chemicals. It doesn't look like that's the case. I think that article may be outdated since it seems like now there are etching chemicals for titanium that are much safer than hydrofluoric acid.

 

[Patrickknives]

I take one off jobs to an engraver like those at the mall doing metal items, they don't charge much and can match about anything they can scan into the computer.