Forced Patina Question

[jm45acp]

Hi first post not sure if this is the correct place for this if not sorry.
I have a Becker/KA-BAR/ESEE Eskabar BK 14 that I am redoing the first thing I did was strip the coating using Jasco premium paint and epoxy remover then I cleaned up the blade removing any tool marks on the spine etc with sand paper and I added some jimping.
I am using heated apple vinegar to do the patina the issue I'm having is the blade turns black like I expected it to but the handle portion doesn't the patina stops about a 1/4 inch past the blade. Is this because of the way the knife was heat treated or the way I cleaned it.
Thanks for any help
John

 

[NJBillK]

I don't know the particulars behind the affect of heat treatment of a blade and it's bearings on chromium for stain resistance.
That being said, I have seen it said by multiple people that are much more knowledgeable than I that there is a connection between HT and stain resistance via free chromium.

Due to each Becker being differentially Heat Treated, I would think that the handle wouldn't take the patina due to the difference between being heat treated and not, or to a lesser degree.

 

[jpm2]

I'll assume the steel in question is 1095 cro-van. If that's correct, and all available Cr (~1%) is free, would that little of an amount really make that kind of difference ?
Sounds like there's still some coating left (varnish, oil, etc). I would rub it down good with 0000 steel wool, clean with rubbing alcohol, and try again.