Sorry it took me so long to get in here MO. I kept passing over this thread and finally had to look at it. Wow! Lots of good stuff covered so far.
I remember when I tried my first etch. It was on a cable damascus dagger I forged for Richard here at the forum. I had no idea what I was doing but it turned out pretty good anyway. I can't even remember where I first read about etching, but I got a handle on it in my usual way. Trial and error. I like the way Jerry Hossum said it. It was a real 'eye opener' for me once I figured out how to do it right.
Etching has helped me tremendously with my forged blades. Especially when it comes to finishes. I used to forge blades and leave that 'as forged' patina on them. I thought it looked cool. Ron Claiborne (Bowie) emailed me quite a few times and even called me on the phone pleading with me to change my ways because the 'as forged' finish hides too many serious flaws. At first I was a little agrivated at Ron because it hit me where I lived. Knife making, after all, was my livlihood so it hurt my baby feelings and I thought he was just saying that my work was inferior. Well, Ron is a great guy and one that I have a great deal of respect for. So, I listened to him even though I continued to produce blades with that 'as forged' finish. Then I went to the ABS school. That changed everything for me.
With what I learned at the school and what Ron had been saying, I was armed to attack this whole 'mountain man' knife thing with some education and experience behind me. I started etching all of my forged blades. And I etched them at different phases in the forging process just to see what happened. It really opened my eyes. Literally. I was embarassed by what I learned. Had I been selling inferior blades before I discovered the etching secret? Quite possibly. And that is a very humbling thing to have to admit to yourself if you forge blades for a living.
What I discovered is what Ed said earlier. There were so many inclusions, heat risers, cracks and such in the blades I was forging that it completely changed my forging processes. What benefit is there to etching a blade? The way I look at it now, if your blade isn't etched prior to final finishing and handle/guard work, you're working in the dark (with carbon steels). I don't mean to attack anyone's methods here. Far from it. This is just what the etching process has done for me and my blade work. It's revolutionized it. It gives me such confidence in my blades and heat treating methods that there's no question about what quality of blades I'm putting out now.
I use a good bit of chainsaw chain damascus for blades. I forge the damascus myself and until I started etching it I didn't truly know how well I was doing with my forge welding. Chanisaw chain isn't easy to weld up. It has to be done in stages and it's easy to think you've got a good, clean billet by just looking it over after grinding off the scale. With etching, I can see problem areas that need more forge welding before I even start to forge the bar into a blade. I guess that's pretty basic when forging damascus. But without that step I would still be putting out questionable blades. All the time thinking I was doing fine. Oh sure, I would discover the flaws during the final etch to bring out the 'damascus pretty' look, but that's the wrong time to discover that your blade is a pretty piece of junk! And the worst part is that if you continue to forge on a bar with inclusions, they just get worse as you stretch the bar out with normal forging. And you wind up with a hard earned piece of scrap damascus. Hard medicine.
I don't etch stock removal blades. Mainly because I don't use the stock removal process for my blades any more. But I would still etch them so I could see how well my heat treating went. And this may be off topic, but I'm going to say it anyway. I used the stock removal precess for almost 5 years before I started forging. I always got my stock from Sheffields and Admiral Steel. But I had no idea what the grain structure was in the steel when I got it. So, I wound up grinding a blade from stock that I knew nothing about as far as it's production methods, temperatures and what not. So, if I were to go back to the stock removal method I'd do things different. I would triple normalize and anneal each blade prior to heat treating. How would you know what the grain size was otherwise? I guess you could etch it before you started grinding on it but you still couldn't be sure unless you normalized it yourself could you? Just an observation that seems to tie into the discussion that's gone on here. Any opinions on my observation?
What a great thread KWM. Thanks for bringing up the question. Sorry I was so long winded. But I'm still pressing the 'submit reply' button