Uneven forced patina

[Alfie Fry]

Hi all,
Im new to knife making and I am currently working on a 6 inch chef knife using 01 tool steel. Ive decided that I want to force a patina on the knife using apple cider vinegar, after soaking it for around 30 mins I took out the knife and for some reason the patina has only formed on a certain patch of the blade and I cant think of any reason for it forming this way as the rest of the blade remains pretty much untouched, could the heat treatment process be something to do with this?
Thanks

 

[12345678910]

The blade has to be super clean, no oil, no finger oils.

steel wool it off, degrease, try again.


vinegar is slow compared to ferric chloride

 

[Jesse Latham]

Decarb

 

[Alfie Fry]

The blade has to be super clean, no oil, no finger oils.

steel wool it off, degrease, try again.


vinegar is slow compared to ferric chloride

I had thoroughly cleaned the knife with acetone before hand and put it straight into the vinegar, will try again though

 

[Don Hanson III]

Use soap and hot wayer. Not acetone. But this blade looks like it wasn't heat treated right. Hard steel will etch dark, not hard etchs light.

 

[Alfie Fry]

Use soap and hot wayer. Not acetone. But this blade looks like it wasn't heat treated right. Hard steel will etch dark, not hard etchs light.

Thanks for the info, I had a feeling it might've been to do with the heat treatment