patina

[STR]

Bluing will dull the edge some yes. Its an acid and a strong enough one to degrade it some. Carbon steel can be affected this way from oranges and other acidic fruits also that can degrade the edge in use. I have heard of guys using blood also for forming the patina. Things like storing the knife between two T-bone steaks overnight and stuff like this are old stories. After cleaning and before handles are installed of course.

There are some other recipes of first taking the knife apart if its already a user,and then heat up some vinegar on the stove and put the blade in. Be sure that the blade is VERY clean first and rub down with acetone or alcohol before putting into the vinegar and be sure its wiped becaues even your fingerprints (from holding the knife) will be etched into the blade if you do not clean it properly! Be sure not to use aluminium utensils, as hot vinegar will cause damage to these also and careful breathing deep. Soon the blade will look as if it is made of Alka-Seltzer and start bubbling. Turn down the heat a bit if the bubbling is too profuse. After 10 minutes or so, you have the perfect even grey patina!

Another neat one that also works is this but its a bit more work. Coat the blade by dipping it in hot candle-wax, scrape out the area to be etched and paint it with iodine. The brown/red stuff we used on scratched and dinged body parts growing up!. The depth of the marking depends mainly on your patience with this treatment. The Wax can keep other areas from being degraded or changed for you. After the etching is complete, you can clean off the wax and move to the vinegar process for the whole blade.
STR

 

[texastonydobbs]

Cool topic , I gotta try this over the weekend

 

[tknife]

Whether rushing a patina, or letting it happen over time, it gives some protection to the blade and a nice personality too. Here's an older pic of my most blade with the most patina and one that is just starting to show some color.

 

[ejes]

My favorite patina comes from the mustard sauce in Crown Prince Sardines. I've never been able to match it with anything else. Found it by accident when using one of my knives to eat them a long time ago.

 

[Dave Costin]

Well you confirmed my suspicions about the acid dulling the blade. I thought about it when I did it that night and that was what came to my mind. It wasn't bad but definetly noticable as I keep a very keen edge on my axes. I use a belt sander then a buffer and compound to bring almost a mirror edge on them. That was why I blued it was to get rid of that shine. Looked nice but also made the axe stand out too much. I am going to get an old Mora out and give this a try. I'm still not sure about dipping the entire knife with micarta scales and all (which of course are not removable). I may have to let it go one it's own.

 

[fedaykincmndr]

I just cut everything in the kitchen and at work (food mostly, but I clean it often). My RAT-3 has gotten a wonderful patina after being used regularly for well over a year.

 

[StretchNM]

Well you confirmed my suspicions about the acid dulling the blade. I thought about it when I did it that night and that was what came to my mind. It wasn't bad but definetly noticable as I keep a very keen edge on my axes. I use a belt sander then a buffer and compound to bring almost a mirror edge on them. That was why I blued it was to get rid of that shine. Looked nice but also made the axe stand out too much. I am going to get an old Mora out and give this a try. I'm still not sure about dipping the entire knife with micarta scales and all (which of course are not removable). I may have to let it go one it's own.

I have never dipped the entire knife in solution, I just fill the solution right up to the hilt. Now, sometimes this means a little portion of the scales will be immersed because of the angle at which the knife rests in the container, but it hasn;t bothered the green micarta on my EnZo, for example. I still wouldn;t immerse an entire knife. Instead, IF you're using the 50/50 vinegar/cold blue, you can dip a shop towel in the mix and coat the spine, end, and underbelly of the tang. I've done it and it works pretty well.

Also, if you'll sharpen your knife or axe right after you complete the forced patina process (and after it dries), it will be ok. You'll just have a thin, shiny line where you sharpened the edge. That's going to end up that way anyway the next time it needs sharpening, so doing it right away should remove any etchant that may continue to work on the edge. In fact, it would probably be good to neutralize the etchant, after completion, by dipping in a baking soda/water mixture and then rinsing well, so that the remaining acids don;t keep working through the pores of the steel on the thinnest part of the knife (edge). I never did this and I'm not a chemist, so I don;t really know if this neutralization process is necessary or not.... just thinking out loud.