lanternnate Posted April 22, 2017 Share Posted April 22, 2017 I had a go at doing an edge quench so I could try to etch for a temper line. I tried doing a coffee etch, and I'm not satisfied with how it turned out. I used brewed coffee and I've read others use instant coffee. I made an assumption that instant was just considered cheaper to waste on etching, but maybe there is a reason instant is used over brewed (my wife would never drink instant so there was none to be had in my kitchen raid, shhh don't tell). I think I'm going to try again with vinegar to see how that goes, but before I do there is another oddness to address. The entire blade was submerged, but the entire piece didn't etch. I don't really mind that the handle didn't etch, but near the ricasso and up at the tip are an issue. I spotted the tip first while checking and thought maybe I overheated it during grinding. Because of the handle and by the ricasso I'm thinking it might instead be due to differences in amount of hand sanding a particular area might have seen. Anyone experience this before? Any tips to be sure your well prepared for a good etch? This was about 12 hours in the coffee taking it out and rubbing down with steel wool a few times throughout and just a steel wool rub down at the end. I can see I got at least a little bit of a temper line which makes me want to try to get etch right rather than just grind and sand back to satin. Edit: Forgot to specify the steel is 1080. My first one with "real steel" Quote Link to comment Share on other sites More sharing options...
lanternnate Posted April 24, 2017 Author Share Posted April 24, 2017 Well I went ahead and sanded back down to 320 and worked my way back up to 600 then did a 24 hour vinegar bath. Better definition this time (maybe a bit too much in some spots as it brought out the the "crystal" look a bit in spots). Came out more even as well it appears. Up next is to try the 2000 grit cleanup and see if I can manage to not cause a need for a third etch Quote Link to comment Share on other sites More sharing options...
lanternnate Posted April 25, 2017 Author Share Posted April 25, 2017 Aaaandddd it's going to need to go again. Made a right good mess sanding it with 2000 grit. Good thing I started with a somewhat thick blade. Maybe I can figure this out before it is a fillet knife... Quote Link to comment Share on other sites More sharing options...
JHCC Posted April 25, 2017 Share Posted April 25, 2017 Degrease before you etch. You might be getting residual oils (even from your skin) that are interfering with the etchant. Quote Link to comment Share on other sites More sharing options...
lanternnate Posted April 25, 2017 Author Share Posted April 25, 2017 I did "attempt" at least to degrease both times, though perhaps not well enough. On the vinegar round I added some dish soap to the vinegar because I read that is supposed to be one of the tricks. I'm still missing something. I may need to cave and get some of the actual harsher etching acid. I was trying to figure out how to do it the the gentler stuff. Quote Link to comment Share on other sites More sharing options...
JHCC Posted April 25, 2017 Share Posted April 25, 2017 Try this: 1. Put on surgical gloves (cheap ones from the drugstore) 2. Wash blade with hot soapy water. Rinse well. Allow to air dry. 3. Clean blade with acetone. Allow to air dry. 4. Place blade in etchant. 5. Remove gloves. Quote Link to comment Share on other sites More sharing options...
lanternnate Posted April 30, 2017 Author Share Posted April 30, 2017 Ok, so reground and worked my way back up through hand sanding to 600 grit. Then did a full degrease routine with gloves, hot soapy water, and finished with acetone. I got instant coffee in place of the brewed coffee and mixed it on the strong side. I'm 18 hours into the soak in coffee now, and the blade doesn't look to show any sign of etching. An area on the handle has darkened significantly though. I remain confused. The only thing I can think is I didn't focus on hand sanding the handle that would be behind the scales. There appear to be some still rough ground sections that didn't etch either though. Is there a magic grit level it needs to be at to etch properly? Quote Link to comment Share on other sites More sharing options...
lanternnate Posted April 30, 2017 Author Share Posted April 30, 2017 After 24 hours and after a few rounds of take out, hot rinse with steel wool, and back in the coffee it's starting to etch up on the blade. Very splotchy though. I guess I'll just keep letting it swim in the coffee longer and see where it goes at this point. Ordering some ferric chloride may be my next thing to try if this at the end is strike three? Quote Link to comment Share on other sites More sharing options...
Andrew Martin Posted April 30, 2017 Share Posted April 30, 2017 (edited) I've played around quite a bit etching things in coffee and vinegar, and I'm wondering about a few things. What dilution are the etching solutions (both the vinegar and the coffee), and what temperatures are you using them at? I usually dilute my vinegar and often dilute my coffee etchants quite a bit, and only use them at room temp, NO hot coffee for me! "A slow etch is a good etch". Usually when I don't get good contrast on a quench line, it has more to do with the HT than the etchant, e.g., piece cooled too much before quench. Also, I'd lose the steel wool and 2000 grit after the etch, they usually just erase any etching IME; but they might help after etching in aggressive solutions like ferric chloride (which I have no experience with). Just had a thought- have you tried HT'ing a scrap piece of the same steel exactly like the knife and see if that poses the same problem? Some steels just don't etch like we want them too.... I've noticed that same "splotchy" effect on rough ground pieces, but I haven't experimented enough with those to know much about that. I would speculate that the greater surface area of rough ground sections (vs. highly polished sections) causes them to etch faster, which promotes the unevenness. Take that with a very large grain of salt though. Edit: What grit are you polishing the blade to before etching? Edited April 30, 2017 by Andrew Martin Quote Link to comment Share on other sites More sharing options...
lanternnate Posted April 30, 2017 Author Share Posted April 30, 2017 The vinegar attempt was straight vinegar not diluted, but also just the standard vinegar not the higher percentage I've read some using. It was at room temp rather than heated. I've read of other methods using heated, but etching a knife in the kitchen would get me in trouble with the Mrs. The coffee on the first attempt was hot from the brewer. Second coffee attempt was room temp instant coffee. Each time I finished to 600 grit on the blade and portions that wouldn't be under handle scales. I only had a small bit of the 1080, so I didn't do a test piece. Maybe 1080 isn't great for this. A lot of examples I've found online to try to go by are 1095, but I've avoided 1095 from what I've read about it being hard(er) to heat treat. Quote Link to comment Share on other sites More sharing options...
Andrew Martin Posted April 30, 2017 Share Posted April 30, 2017 (edited) You might try the coffee from the brewer at room temp. I've no experience with instant (we can't stand the taste), but I believe I've heard some brands of instant perform better than others. In addition to the above, try sanding it to 1000 grit or higher (I'm assuming you wouldn't mind a mirror polish since this will be etched?), as you saw on the rough ground portions of the handle, higher grit polishes tend to etch better. I've etched at 600 grit before with minimal issues, but it can't hurt to try. Other than that, I'm afraid I'm out of suggestions; maybe the next one will behave! Just remembered a project I did last year: I rubbed a cotton wad soaked in lemon juice (bottled not fresh) on a blade that was edge-quenched, and it did work reasonably well as far as contrast was concerned, I'll try to find pics. Edited April 30, 2017 by Andrew Martin Quote Link to comment Share on other sites More sharing options...
lanternnate Posted May 3, 2017 Author Share Posted May 3, 2017 So I've just kept going with this current etch. I'm about 4 days in now. Each morning and night I take it out, wash it off, hit it with baking soda, wash again, scrub with steel wool, rinse again, dry, rub with acetone, dunk it back in the coffee. I've also changed the coffee out twice at this point. The splotchy etching spots have continued to grow and even out. I guess maybe my store brand instant coffee could be on the weak side. Up at the tip still hasn't evened out, so it's getting another night in the coffee (I figure why not at this point). I'm starting to get happier with the look. If the tip evens out I'll be much happier than I was with the vinegar attempt. I may get some ferric for the next knife I attempt this with. Quote Link to comment Share on other sites More sharing options...
lanternnate Posted May 6, 2017 Author Share Posted May 6, 2017 Andrew, thank you so much for the idea about lemon juice and a cotton ball. After 4 days soaking in coffee I still really wasn't happy with it. In waiting for it to fully etch some places, it crossed the line to over etching in others. I was ready to throw it through the wall, but I decided as one last hurrah I'd try your lemon juice idea. I sanded it back down (not even to perfectly cleanly sanded because I had low hopes at this point), and gave it a try. After about 5 minutes of rubbing it all of a sudden started magically looking right. Twice I rinsed it and scrubbed with steel wool to blend a bit (may not have needed to do that if I had fully cleaned up at sanding). In the end it got 3 rounds of lemon scrub about 5 minutes or so each. On the last one it just got rinsed and nuetralized. It now looks pretty much exactly like I was trying to get from the beginning. Fourth time is a charm, but only with your help! Here it is with the handle scales glued on but not fully shaped yet. Sorry Frosty, I still can't take a good picture regularly and trying to take one that shows the etching is even harder. I'll try to get better I promise Quote Link to comment Share on other sites More sharing options...
Andrew Martin Posted May 6, 2017 Share Posted May 6, 2017 Yay! I'm very glad I was able to help! I found the pic of that test knife I did last year, not the best picture either but you get the idea: Quote Link to comment Share on other sites More sharing options...
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