The terrorist in the world of knifes is the misrepresented blade. The performance potential of any knife needs to be represented as it is for what it is. For those of you who have followed this thread you will now have an understanding of the value of etching blades. The etch does not stand alone, it must be verified by testing the qualities sought.
The misrepresented blade hurts all for it erodes confidence on the part of the client who must depend upon the word of the maker. The etch is only one of many quality control measures. Thank you for your participation in this discussion. Thanks to Keith for the opprotunity.
Keith, I'm just glad that I had something to add to this thread. Something of interest anyway. As I've mentioned in most of my posts, these procedures have worked for 'me'. I don't pretend to be some guru with all the answers but I'm happy to share my experiences.
I would be very appreciative of having it explained how one can distinguish absolute hardness by etching a blade, especially by the naked eye. Seeing that there are differences in hardness between zones I can understand, but establishing the actual hardness for spine versus edge versus transition zone I am unclear on. If all one can tell is whether the transitions are there, you still don't know if it's the correct hardness. Any clarification would be appreciated.
Also, I would like to know what is the difference between a scratch on a mirror polished blade versus one on a satin polished or bead blasted surface. The steel is still the same and just as prone to scratch. (A satin blade obviously can be resanded easily.) An etched blade may have more resistance to scratching, since it now has a hard oxide surface, but that is the only circumstance I can think of. Also, what is the effect on the steel at the thin edge when exposed to an oxidant such as ferric chloride (ie, how deep does it penetrate; how much of the edge is compromised?).
I don't use the etch to determine hardness Fitzo. I don't know of anyone that does either. The etch has very little to do with hardness except how it reacts to the steel in it's various hardened states. But I don't think the etch will tell you just how hard the steel is.
And the trick is to etch the blade before you grind the primary edge on. You etch a finished edge and there goes your edge. There has to be some sharpening after the etch. I see no way around it unless it's a display only blade. That's the way it looks from Arkansaw anyways.
Fitzo: Good questions! The exact hardness can not be tetermined from the etch, that is the domain of the Rockwell tests. After having a number of blades etched, and then testing for hardness, the bladesmith can come to an understanding of hardness by reading the etch in reference to his steel and paying attention to his methods. Not an exact science, but all of my blades tested have run 59 to 60.
By always testing for cut and edge flex we can be prety darn close to knowing where we are when the laboratory data supports our results learned by performance testing.
There is no one aspect that tells all, they compliment each other.
The as etched edge cuts very well, but lacks stamina, therefore has to be sharpened down to more stable steel. This etch does not penetrate very deeply when done properly.
We all have our opinions, but to say that a maker is trying to hide or cover up defects in his finished product because he uses a mirror finish or beadblast is absurd, I don't etch my blades because I don't care for the look, they look unfinished to me, but I'm not going to say anything negative about another makers work because of his techiques or beliefs. I don't etch but I test the heck out of my blades and I stand behind my work with a guarantee against workmanship defects, if one of my blades fail when used like a knife and not a hammer, prybar or screwdriver, I'll stand behind it. Some on this thread have stated that they won't buy a knife anymore if its not etched, all I can say is that will be your loss, there is a lot of great makers that use mirror, beadblasted and satin finishes without etching, if your worried about buying a poor knife, than only buy from a maker that stands behind his work. I would rather have a blade from a maker that has physically tested their blades and techiques than from a maker that draws his conclusions from an etch.
I don't mean to cross swords with you Bill, but I think you might have missed something in this thread. There has been some real good input about the 'process' of etching blades. It's not the 'best' thing you can do for a knife by any means. It's just another step in the process of quality control. And it will teach you something about your processes. I don't think that anyone here has intimated that they forge up a blade and etch it and call it good. To the contrary, the etch is used to find flaws and things that could potentially cause your knife to fail under normal use.
As far as standing behind your work, I don't know of any good makers that don't do that. I can tell you're angry by your post. There's no need for that Bill. We can all learn something if we'll just read what's here and take what we need from it. Everyone has an opinion, like you said. Let them. It's no big deal or any skin off my nose one way or another. The same for you.
Calm down Bill. You're among friends here who just want to share and learn like you. That's why I'm here. To learn and also to help others learn about things they don't understand. I really enjoyed your post on heat treating. It shows your willingness to learn as well as teach. Keep it up and thanks for sharing.
Bill, I agree with you that if we decide to buy knives from only makers that use etching as a tool to learn more about the blades they make, that we will be missing out on some great knives. I personally don't care for mirror polished blades, but I do like a satin or almost mirror polished blade. I think that etching is just a way to find out more about the things that could be wrong with a blade that has been made. It can also show you what you are doing right.
I personally think you make great knives and wouldn't hesitate for a minute to buy one. In fact, at some point in the not to distant future I plan on doing just that. If makers decide that etching their blades is something they can learn from, then great. If not, that is up to them and I do not think any the less of them for it. There is room in the world of knives for makers that both etch and do not etch. That is what is so darn great about it.