Acid/coffee etch rubbed off

[Hntr11]

Hi everyone,

I wanted to reach out in hopes that some of you might be able to explain what I’ve experienced on the most recent knife I’ve finished. As the title suggests the ferric/coffee etch I did just rubs off during finishing.

This is a 1084 mono steel blade that I took to 600 pre etch. Etch went great, did 3 dips@15sec, 5min, 7min lightly sanding oxides with 1500grit between except after the last. Came out very nice and even, rinsed with windex and water then straight into the coffee for 3 1/2 hours. Came out jet black, I was pumped. Rinsed and then started applying carnauba with a heat gun. Wiped most of it away after re heating and then let it set.

This is where problems started. As soon as I started polishing with the sunshine cloth as light as possible and the oxides started coming off like crazy. Additionally no matter how I “polished” with the sunshine the wax just smudged, I tried re heating it and wiping more off with the same result. By this point the jet black was more of a gun metal in quite a few spots so I decided to stop and just oil it. After the oil bath I lightly wiped off and more oxides just fell off on the paper towel. There’s now a dull finish everywhere there seems to be “surplus wax” as well.

Is this normal on a mono steel blade of did I screw something up in the post etch process(this is my first etch, I’ve just cold blued to this point)? I feel as though I should’ve just cold blued it but I wanted to try the coffee etch and thought it might be more durable.

I would post a picture but I can’t figure out how.

Thanks
-Nick

 

[Karl B. Andersen]

I hope this coffee BS goes away for good. It is worthless.
Nice contrast? Sure.
Until you touch it.

 

[Hntr11]

I wish I would’ve heard that from the start. I was under the impression it was pretty durable. Bad source I guess

 

[Taz]

Lots of bad info on the internet!!

Acid etching just makes oxides on the surface, which are easy to wipe/rub off. I have found less oxides wiping off when I let it sit with WD-40 or mineral oil on the surface for a day or so. Some people bake the knife in the oven for a bit which supposedly helps the oxides "set up" more. Gator piss recommends spraying down in wd-40 and letting it sit for 40 hours to let the oxides set up.

I acid etched a 52100 blade in ferric chloride for almost 3 hours, checking and wiping oxides off every 30 minutes or so and got a nice dark black blade. Haven't heard back from the customer how it's holding up, but he also told me it was too pretty to use and hadn't used it yet when I checked with him a month or so later...lol.

Ed Caffrey uses clear Satin Gun Kote over his blades to protect the damascus finish and oxides from wearing off.

There was a guy on here a few months ago posting about a nano coating that can be wiped on blades that protects them, too.

 

[Bill DeShivs]

Sunshine cloths have a light abrasive. They should not be used with wax.

 

[Hntr11]

Lots of bad info on the internet!!

Acid etching just makes oxides on the surface, which are easy to wipe/rub off. I have found less oxides wiping off when I let it sit with WD-40 or mineral oil on the surface for a day or so. Some people bake the knife in the oven for a bit which supposedly helps the oxides "set up" more. Gator piss recommends spraying down in wd-40 and letting it sit for 40 hours to let the oxides set up.

I acid etched a 52100 blade in ferric chloride for almost 3 hours, checking and wiping oxides off every 30 minutes or so and got a nice dark black blade. Haven't heard back from the customer how it's holding up, but he also told me it was too pretty to use and hadn't used it yet when I checked with him a month or so later...lol.

Ed Caffrey uses clear Satin Gun Kote over his blades to protect the damascus finish and oxides from wearing off.

There was a guy on here a few months ago posting about a nano coating that can be wiped on blades that protects them, too.

Thank you for the advice! I imagine the etch might last longer on a damascus blade cause it has somewhere to “hide” between the high spots?

 

[Hntr11]

Sunshine cloths have a light abrasive. They should not be used with wax.

That’s kinda what I was thinking but I saw so many makers (will stelter, Jason knight, etc) using it after the wax I figured it was a solid process. Makes me wonder if it wasn’t a sunshine cloth they used.

 

[Stacy E. Apelt - Bladesmith]

I regularly get a lot of flack when I say a coffee etch is worthless .... but as you found out, it is not durable. Same for most really dark FC etches. It is pretty, but any abrasion will scratch it or rub it away. Coffee etch is for shelf queens only.

 

[Hntr11]

I regularly get a lot of flack when I say a coffee etch is worthless .... but as you found out, it is not durable. Same for most really dark FC etches. It is pretty, but any abrasion will scratch it or rub it away. Coffee etch is for shelf queens only.

Definitely a lesson learned! Looks like I’m going back to the cold blue

 

[knarfeng]

Might I butt in and suggest looking into electro-etching? Far more durable than an acid etch. It does require equipment. But it's durable enough that it's used on aircraft parts.

 

[Hntr11]

Might I butt in and suggest looking into electro-etching? Far more durable than an acid etch. It does require equipment. But it's durable enough that it's used on aircraft parts.

I have one for my makers mark but have never thought of using it for the entire blade. I’m curious how good the surface finish would be? Have you done this on a knife?

 

[knarfeng]

I have one for my makers mark but have never thought of using it for the entire blade. I’m curious how good the surface finish would be? Have you done this on a knife?

Sorry. No. I would not recommend using that on the entire blade. I misread the thread.

 

[Hntr11]

Sorry. No. I would not recommend using that on the entire blade. I misread the thread.

Ok gotcha

 

[REK Knives]

Sunshine cloths have a light abrasive. They should not be used with wax.

That's interesting... A good bit of this video is Kyle Royer working with coffee, carnuba wax and sunshine cloths...

 

[Hntr11]

That's interesting... A good bit of this video is Kyle Royer working with coffee, carnuba wax and sunshine cloths...

That was one of the videos I watched and I followed what he did as best as possible. I’m starting to think the main reason the coffee etch is wearing so easily is because it’s not protected by the high steel it would be in between on a Damascus knife.

 

[REK Knives]

That was one of the videos I watched and I followed what he did as best as possible. I’m starting to think the main reason the coffee etch is wearing so easily is because it’s not protected by the high steel it would be in between on a Damascus knife.

Normally he let's it sit in the coffee overnight I believe. But I haven't ever done it before so I don't know what works and what doesn't

 

[Hntr11]

That was one of the videos I watched and I followed what he did as best as possible. I’m starting to think the main reason the coffee etch is wearing so easily is because it’s not protected by the high steel it would be in between on a Damascus knife.

Normally he lets it sit in the coffee overnight I believe. But I haven't ever done it before so I don't know what works and what doesn't

Yeah I would say there’s 3 main differences between what he did and what I did. His blade was damascus, he left it in the coffee for days instead of hours, and he used a blue sunshine instead of the yellow I used. I didn’t realize there were different “grits”.

 

[DevinT]

What is left after etching with ferric chloride is carbon on the surface that’s why mild steel does not etch dark.

Hoss

 

[weo]

Another tip I've heard is to let the oxides sit overnight, some even try to 'bake' it in a low oven (200F). In my experience, less oxides get rubbed off during the final cleaning/polishing if sits overnight before cleaning (be sure to neutralize the acid though).
However, I've only etched pattern welded blades, never monosteel and I believe that you are correct when you say the oxides are protected from getting wiped off by the topography.

 

[Hntr11]

interesting about baking them on.