Re-etching KAI composite blades?

[Misanthropia]

So my beloved ZT 0454 has seen a fair amount of use and the etched CPM-D2 portion has definitely started to lighten and wear away. Does anyone know how they etch the steel in the first place? And is there a way to repeat this process?

Thanks guys!

 

[samuraistuart]

Sure, it's pretty easy. (Wow....what a pattern on that knife....wasn't familiar so I looked it up). I'll describe how I etch a hamon, should apply quite well to your knife. Go to your kitchen stove and put a pot on it, and fill it up a bit with vinegar and a bunch of lime juice. (Note....ferric chloride is a much faster etchant...I prefer the vinegar/lemon or lime....YMMV). Add a bit of dish soap in there as well (helps break up surface tension or whatever and makes for an even etch....probably not needed in your case, but for a hamon etch I really need the soap in there). Once your etching solution is almost boiling, dip a towel in there and continuously wipe the blade down on both sides. Wipe down heavily one side, flip and wipe down, flip wipe down...on and on. After a few minutes of this, you'll see the etch start to take. Some recommend just dunking the whole blade into the solution and let it sit in there....and that is perfectly fine to do (I'm not talking about the ferric chloride....that stuff is much faster and I wouldn't let a blade sit in that stuff for too long at all). If your knife is a complete knife, handle on it and all, probably best to wipe the blade down instead of submerging it. Once the etch is where you want it, hose it down with Windex to kill the chemical reaction from further taking place. For a hamon, I then come along with metal polish and polish the whole thing. However, I know some guys leave the oxides on the blade for a darker hamon, and you may go that route. I hope this helps. Not sure if it will give you exactly what you are after....the ferric chloride does a much darker/faster etch than vinegar and lime juice. I would give it a shot. Good luck.