Does anyone know how to chemically etch tungsten?

[Ni518079]

I have had some good luck modifying my darts with steel and diamond files but have been trying to etch and remove material chemically. I know acids won't work but I heard that bases can ruin tungsten rings and such. I tried some acids anyway, didn't do anything. Tried some bases (even 15% h2o2), didn't do anything. Tried electro etching, didn't do anything. Anyone have any suggestions? Maybe a chemistry teacher out there?Guests cannot see images in the messages. Please register at the forum by clicking here to see images.

[Cankles of Fury]

I'll look into this for you. I will say 15% h2o2 isn't a strong base at all. You'd probably have better luck using lye or bleach. What kind of result are you wanting to achieve?

Acids and bases are both corrosive and if it's not reacting I'm guessing the acids you are using just aren't strong enough. I should go test out some 12M sulfuric acid but I hate dealing with that stuff :p

[Ni518079]

Not really sure what I want to achieve. Maybe just some pitting maybe grooves or spots, who knows. Just like playing with my darts. I recently modded a tomahawk and etched the head with salt water and a couple batteries. I though it was cool and wanted to try something like that on my darts. Also the h2o2 was just because of the oxidative qualities as well.

[Cankles of Fury]

I've heard bleach will pit the darts, you might try that.

[The D'Artist]

https://www.cleanroom.byu.edu/wet_etch.phtml

1 : 1 HF : HNO3
1 : 1 HF : HNO3 – thin films
3 : 7 HF : HNO3
4 : 1 HF : HNO3 – rapid attack
1 : 2 NH4OH : H2O2 – thin films good for etching tungsten from stainless steel, glass, copper and ceramics. Will etch titanium as well.
305g : 44.5g : 1000ml K3Fe(CN)6 : NaOH : H2O – rapid etch
HCl – slow etch (dilute or concentrated)
HNO3 – very slow etch (dilute or concentrated)
H2SO4 – slow etch (dilute or concentrated)
HF – slow etch (dilute or concentrated)
H2O2
1 : 1, 30% : 70%, or 4 : 1 HF : HNO3
1 : 2 NH4OH : H2O2
4 : 4 : 3 HF HNO3 : HAc
CBrF3 RIE etch
305g : 44.5g : 1000ml K3Fe(CN)6 : NaOH : H2O – very rapid etch
HCl solutions – slow attack
HNO3 – slight attack
Aqua Regia 3 : 1 HCL : HNO3 – slow attack when hot or warm
H2SO4 dilute and concentrated – slow etch
HF dilute and concentrated – slow etch
Alkali with oxidizers (KNO3 and PbO2) – rapid etch
H2O2
...and

For selectivity you should choose an alkaline etch with not too high pH. The etchant has to be oxidizing. In my opinion from the above page those two could be candidates:
1 : 2 NH4OH : H2O2
305g : 44.5g : 1000ml K3Fe(CN)6 : NaOH : H2O

[Milkysunshine]

This makes sense... bleach will etch and discolor a barrel, but vinegar will not.

My own experiments have shown me this! I don't need no fancy shmancy science!!

(I kid... I love science.... I love having the answers when my kid asks why? My wife just says 'ask daddy'.)