Damascus Etch: What have I done wrong?

[tkroenlein]

I *attempted* etching my first damascus blade. It looks...wrong.

The particulars:

11 layer 80CrV2 and 15N20. Slow twist. Hand hammered. Welded perfectly, no flux. Rough ground to 220 ish, coated in Turco, normalize, thermal cycled, quench in 10 sec commercial oil. Hand sanded to a an honest 400 grit.

Etched in fresh 3:1 ferric chloride. Washed and rinsed in hot water, degreased with isopropyl.

Etched attempted 2 times. Same result each time.

80CrV2 layers have a couple of shiny spots. 15N20 turns as black or blacker than 80CrV2. Oxides don't scrub off with steel wool. 15N20 layers are obviously more resistant to etch because they are higher than 80CrV2 after 15 minutes. Any advice appreciated.

 

[Owl]

Did you use distilled water to dilute the ferric chloride?

 

[tkroenlein]

Yessir.

 

[EdCaffreyMS]

Based on what I see in the photos...... NOT CLEAN prior to etching. When it comes to etching, the word "clean" cannot be overemphasized. Latex or nitrile gloves, clean once with acetone or alcohol, then a second time with windex. Then, be SURE the windex is ABSOLUTELY DRY (one drop of windex will kill an entire container of ferric.)

Another thing that often happens with ferric that's been used a few times...... look at the surface of the ferric.....if you see ANY film on top, or any rainbow colored bands.......that is contamination..... take a new, clean shop towel and clean the surface.

Here's another insight. DO NOT use household paper towels to clean prior to etching....especially white paper towels. Something in the finishing/bleaching process during manufacturing, leaves chemicals in the paper towels, that will leave residue on a blade (usually appears as a very faint streaking on a blade/steel). Personally, I recommend using Scott's brand "shop towels" (the blue ones). They clean without leaving any residue, and make your life much nicer.

 

[tkroenlein]

Based on what I see in the photos...... NOT CLEAN prior to etching. When it comes to etching, the word "clean" cannot be overemphasized. Latex or nitrile gloves, clean once with acetone or alcohol, then a second time with windex. Then, be SURE the windex is ABSOLUTELY DRY (one drop of windex will kill an entire container of ferric.)

Another thing that often happens with ferric that's been used a few times...... look at the surface of the ferric.....if you see ANY film on top, or any rainbow colored bands.......that is contamination..... take a new, clean shop towel and clean the surface.

Here's another insight. DO NOT use household paper towels to clean prior to etching....especially white paper towels. Something in the finishing/bleaching process during manufacturing, leaves chemicals in the paper towels, that will leave residue on a blade (usually appears as a very faint streaking on a blade/steel). Personally, I recommend using Scott's brand "shop towels" (the blue ones). They clean without leaving any residue, and make your life much nicer.

Thanks Ed. Would that cause the blackening of the 15N20 as well?

 

[EdCaffreyMS]

Would that cause the blackening of the 15N20 as well?

Yes. Going back, and looking over the photos again, I'm certain there is contamination. The dark on the blade leads me to believe there is either some kind of contamination film on the surface of the ferric, or on the blade. (mean it didn't get cleaned well enough)

I would recommend hand sanding the blade again, until you get a clean 600 grit finish (you don't have to sand the topography out, just make sure the entire thing is to a nice 600 grit)........ then put on NEW/CLEAN nitrile or latex gloves, and follow what I wrote in my previous post....MAKING SURE the clean is ABSOLUTE.... and give it another go. I place whatever I'm etching on a piece of Stainless steel wire (spools are cheap at Harbor Freight), make sure there is no scum or film on the surface of your ferric (if there is, surface tension causes it to get spread across whatever you etching, as it lowered into the ferric) Submerge the entire blade, count to 10, then pull it out and look..... if you have any streaks or spots that are not etching (look clean/shiny), you didn't clean it well enough...... pull it out, neutralize, then go through your cleaning procedure again.

Just trying to cover all basis...which is tough...... IF you happened to use non-stainless wire when you etched previously, something like iron wire, a coat hanger (don't laugh, people have), then there's a good chance you've contaminated the ferric, and to ever get decent results, you'll have to throw it out, and make up a new batch. Like I said, when it comes to etchant and etching..... CLEAN, CLEAN, CLEAN.

 

[tkroenlein]

Yes. Going back, and looking over the photos again, I'm certain there is contamination. The dark on the blade leads me to believe there is either some kind of contamination film on the surface of the ferric, or on the blade. (mean it didn't get cleaned well enough)

I would recommend hand sanding the blade again, until you get a clean 600 grit finish (you don't have to sand the topography out, just make sure the entire thing is to a nice 600 grit)........ then put on NEW/CLEAN nitrile or latex gloves, and follow what I wrote in my previous post....MAKING SURE the clean is ABSOLUTE.... and give it another go. I place whatever I'm etching on a piece of Stainless steel wire (spools are cheap at Harbor Freight), make sure there is no scum or film on the surface of your ferric (if there is, surface tension causes it to get spread across whatever you etching, as it lowered into the ferric) Submerge the entire blade, count to 10, then pull it out and look..... if you have any streaks or spots that are not etching (look clean/shiny), you didn't clean it well enough...... pull it out, neutralize, then go through your cleaning procedure again.

Just trying to cover all basis...which is tough...... IF you happened to use non-stainless wire when you etched previously, something like iron wire, a coat hanger (don't laugh, people have), then there's a good chance you've contaminated the ferric, and to ever get decent results, you'll have to throw it out, and make up a new batch. Like I said, when it comes to etchant and etching..... CLEAN, CLEAN, CLEAN.

Thanks again. This is the result of the second attempt. What you've said makes perfect sense. It seemed as though I was smearing something around on the first attempt-and now that you've mentioned paper towels-I'll bet it was something in the towel going into solution from the alcohol. I'll give it another go this weekend. Again, much appreciated.

 

[tkroenlein]

Ok. I think I have this figured out. I re sanded and cleaned as suggested. Exact same result. And I mean exact.

So now I am assuming that the shiny spots weren't hard steel. I had ground this knife very thin before heat treat. I coated it with Turco. I'm thinking that the Turco is has "contaminated" a pretty good depth in the blade. As can be seen in the pics in my first post, the hollows on the handle is etching correctly, shiny 15N20 and black 80CrV2. The same is true on the spine of the knife. So I think the shiny spots on the blade is decarbed steel where the Turco was too thin that needs ground clean, and the bevels need that contaminated layer ground out. Does this sound reasonable?

Take 3 tomorrow. After a more thorough clean up grind and more sanding. :/