Tool sharpness and when to say farewell

[The_real_janderson (Jonathan Anderson)]

Yep, I use sodium hydroxide (lye), which works really well.

Surface Analysis of ZrN Endmills After a Sodium Hydroxide Bath

As some of you might have seen, I am testing some Carbide3D ZrN single flute endmills and ran my 1/8” one too hard and got it gummed up with aluminum on the surface. With the naked eye, it just looked gray, almost like the coating wore off, but with closer inspection, it was aluminum coated onto the surface. [image] [image] [image] I decided to do some research on how to remove the aluminum and knowing that sodium hydroxide (NaOH) reacts with aluminum to form water soluble sodium aluminate …