How To Acid Etch with ferric chloride

[Larry Van Dyke]

I tried acid treating two knives today for the 1st time. Goal was to darken both and stone wash. Both were covered with Caig Labs CL-Etch-16 Ferric Chloride PCB Solution. The blade portion of both knives darkened nicely but the handles were much lighter making both knives two tone. Even as the lay in the solution for 20 minutes I could see the blade portion turn black and the acid seemed to have to effect on the handles.

What am I doing wrong and how can I get an even finish? Thanks.

 

[ren01228]

How were they heat treated? Hardened steel and unhardened steel will etch differently. It makes sense if this was done in a forge.

If HT was done in an oven where the entire knife gets hardened it’s likely decarb. It really doesn’t darken up much at all though. You would have ground through it on the blade portion when grinding the bevels. If you didn’t grind the handle at all post HT that’s probably your issue.

 

[Larry Van Dyke]

Oh yeah, that's it!!!! Only the blade portion was hardened. No wonder it's a different tone. Thanks so much for the answer. Wow who!!