First layered Damascus-etching

[banjobend]

Hey all, I've made a few knifes in the past, including some San Mai and canisters, but I just made my first layered Damascus blade. Everything went really well but I can't seem to get that good pattern like I see so many others achieve.

My knife is 80 layers of 1095/15n20. All ground clean before welding. After grinding and quenching in canola oil, I sanded down to 600 grit. At this point things were looking great!

I cleaned it with dish soap and water, then, while wearing nitrile gloves, placed in a 4:1 distilled water, ferric chloride etchant. It didn't come out so good.

I then sanded lightly with 1500 grit and re-etched. I did this 3 times, 15 minutes each time. Results are not so good.

Anyone have any advice for me? Can I grind it down and start over?

https://imgur.com/Nkyhd2K

https://imgur.com/MR6KOIJ

 

[weo]

Did you grind the decarb off the blade after heat treating? If not, this is your problem.

 

[banjobend]

Did you grind the decarb off the blade after heat treating? If not, this is your problem.

I sanded it pretty aggressively after the heat treat. Started with 50 grit up to 600. That should take it off right?

One thing I just thought of that may or may not matter. I didnt temper it in the oven after quenching it. Would that affect the etch?

 

[weo]

I sanded it pretty aggressively after the heat treat. Started with 50 grit up to 600. That should take it off right?

Maybe, hard to know without seeing what you did, what you call 'aggressively', etc...

One thing I just thought of that may or may not matter. I didnt temper it in the oven after quenching it. Would that affect the etch?

Shouldn't effect the etch, but it's an extremely bad idea not to temper immediately after quenching, even if it's just a snap temper of 200F for 30 min,

 

[velegski]

Just curious, why no tempering cycle, that steels brittle.
Even untempered damascus will show a pattern with Good enchant.
What temperature is your etching solution. Below 70 f it takes way longer to get desired results.

 

[banjobend]

Maybe, hard to know without seeing what you did, what you call 'aggressively', etc...

How much should I be sanding/grinding after heat treating? Everything I've read just says to sand, starting around 120grit.

just curious, why no tempering cycle, that steels brittle.
Even untempered damascus will show a pattern with Good enchant.
What temperature is your etching solution. Below 70 f it takes way longer to get desired results.

Im very new to this and I guess I just got to excited to start sanding and see a pattern. Is it to late to temper? Re quench and temper?
I made sure the solution was warm, I had it near my wood stove till the container felt warm to the touch. Not hot.

 

[weo]

How much should I be sanding/grinding after heat treating?

Decarb is only a few thou deep. I do some grinding after HT before starting hand sanding, so I'm not sure how long it would take to removeby hand.

Is it to late to temper?

No, but the longer it goes untempered, the more risk of cracks. Some steels are more forgiving than others. Some will crack if you wait 5 minutes.

 

[banjobend]

Decarb is only a few thou deep.

I really feel like I took quite a bit off. Is there a way to tell if its been completely removed?

I just threw it in the oven, maybe after that I'll grind it down and start over.

 

[velegski]

I'm not sure what you are looking from the etch. Generally speaking there's a color difference but I think if your are looking for those really dark and shiny areas you won't find them just from the etch. To achieve those really dark contrasts some use bluing or super strong concentrated instant coffee.
Also you could be polishing out any color differences by too much sanding. To me it's a really light hit just to take off and sharp edges left from etching. Or I use 4-O steel wool.

 

[Tom Lewis]

It looks like to me that you have not etched it enough. I use Muratic acid to etch Damascus. I do not add water to the acid. I have found that old acid will not etch as fast as new acid.

With room temperature Muratic acid it usually takes me five, five minute cycles. After each five minutes I dip in water and quickly sand with a piece of 800grit sandpaper. I use the same sandpaper all the way through. After the etch gets as deep as I want I put cold bluing on the blade to bring out the pattern.

 

[banjobend]

That looks good! I'm not expecting mine to look that nice since it's my first go at it, but that's what I want. Maybe someday.

I tempered in My toaster oven today, gonna grind it down and try again tomorrow.

 

[banjobend]

I made this leaf spring San Mai and the high carbon steel stands out nicely. Same exact process I'm using now, different steel I guess, but it's frustrating.

 

[DevinT]

I sanded it pretty aggressively after the heat treat. Started with 50 grit up to 600. That should take it off right?

One thing I just thought of that may or may not matter. I didnt temper it in the oven after quenching it. Would that affect the etch?

Fresh martensite (untempered martensite) does not etch well, only tempered martensite etches.

Ferrite also does not etch well. Pearlite and tempered martensite etch well.

Temper at 375’f 2 x 1hour each time, then re-etch.
Hoss

 

[velegski]

Thanks Hoss! That explains alot. I knew the untempered didn't etch well but didn't understand the why's. Thanks again

 

[banjobend]

So I ended up tempering my blade and grinding and etching again, still not much of a pattern.

After reading another users recent post about the problem he is having with his San Mai, I'm thinking I might have the wrong steel. Like maybe the 15n20 isn't actually that.

This ever happen to anyone?

 

[A.McPherson]

B banjobend not recently. I have stopped buying metal from unknown sources, and really only use ones that specifically deal to knife makers i.e. pops knife supply, alpha knife supply, jantz, Texas knife makers supply etc.

Quite frankly anyone dealing on Amazon or eBay or billybobsprettygoodstufflist dot com are immediately suspect, unless they come highly recommended by somebody in the know.

 

[Joshua Fisher]

Also since it’s not been mentioned canola is a poor choice for quench oil with those steels, it’s not really fast enough and if the steels aren’t properly and evenly hardened you won’t get a good contrast in the etch. I’d highly suggest getting 5 gallons of parks 50 quench oil. It will last a very long time and is very economic when you think about how many blades you’ll be able to properly harden in the oil.

 

[banjobend]

Well it turns out the steel blanks I got weren't what the seller said they were. Decided just to finish the knife anyway. Came out nice but I sure wish I had that good pattern. Maybe next time.