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Sorry if someone's already asked this. I couldn't find what i was looking for.

 

Im very new at knifemaking but recently i got a premade damascus knife blade as a bday gift.

 

The blade looked kinda dirty, and the pattern kinda dull. So, i started by polishing it with a dremel which made the upper steel really shiny. However the bottom steel looked kinda beige/light grey so i decided to etch it in coffee to darken it.

 

After 5 hours, not much color change. The edge of the blade that was previously just shiny metal now showed a damascus pattern, so the etching did work. The shiny steel stayed shiny. However, the other steel kinda just turned beige with splotches of brown.

 

I dont know if it just needs more time or what went wrong, any advice would be super helpful.

 

IMG_20210228_140618.jpg

The blade after my etch.

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Welcome aboard!

 

I suspect it just needs more time in stronger coffee.  Like, overnight in a batch of instant coffee brewed to at least five times normal strength.  After that the not-shiny parts should be a full black, and you may need to lightly hit it with fine paper on a hard backing to get the bright stripes back.

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I like to use gun bluing oil to really darken the carbon steel, and it doesn't do much to the nickel steel layers. My typical routine is to

-etch in ferric

-clean, sand high layers at 600 or 1000 grit

-coffee etch in hot water with as much instant coffee as will dissolve in it (leave for a few hours) only if I need it to be more dark than usual

-clean, lightly hand sand again

-wipe on cold bluing oil to wet surface, repeat as needed to leave low layers as black as desired

 

This way I am able to achieve almost completely black surface on the low layers that is fairly durable and consistent. It does depend a little on the grade of steel. It depends on how strong your etching solution is and what it is made of, but usually it will slow down in ferric chloride as a 'residue' builds up. For strictly topographic etching (muriatic for example), that doesn't apply and it will continue to etch away. With ferric, you'll want to clean it either way to clean the surface of the low layers. With coffee, it is far slower of an etch and really doesn't do much to achieve topography, more so just contrast if etched on a roughly similar time scale as ferric. I like to use soap and water with a cotton ball or q tip to clean but not necessarily scrub the blade. Same goes for sanding the high layers but more to keep the surface shiny without touching the low layers.

 

Like anything, it's a lot of trial and seeing what works best for your workflow. I personally would highly recommend the bluing oil (available online or at any gun store), but that's just my preference. 

 

Cheers!

 

John

 

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I first found out about the coffee etch/coloration back in 2015 at the first ICCE show in Kansas City from an Italian maker named Milko DiPaco. He had this Damascus blade and it was darker than I had ever seen before. I asked what he used for an etch and he said coffee. I said coffee? and he replied Nescafe. When I asked how long he etched it for, he said 3 days.

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I darken sword fittings in a mix of tea and coffee 8 or 10 tea bacg and a jar of instant coffee to one big saucepan . and then put the fittings on bring to the boil and leave a few hours...they will go very dark.

 

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8 hours ago, owen bush said:

I darken sword fittings in a mix of tea and coffee 8 or 10 tea bags...

Wait, they allow tea-bags on your "island"?  I find that almost as astonishing as an Italian having access to Nescafe :blink:

 

Does anyone else struggle with trying to keep/store their coffee/tea mixture?  I like to keep it to use again later, but mine is always growing mold.

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I use half a bottle of instant coffee mixed in about a jars worth of water, then I add some lemon juice to it. Coffee by itself would take an hour to hour and a half but with lemon juice it cuts the time down to about 15 minutes. They come out dark.

 

I've noticed too that certain steels etch darker than others. 1084 etches dark while 1095 and 52100 don't etch as dark. I think it has to do with manganese amounts. The more manganese, the darker they seem to get.

1 hour ago, Brian Dougherty said:

Wait, they allow tea-bags on your "island"?  I find that almost as astonishing as an Italian having access to Nescafe :blink:

 

Does anyone else struggle with trying to keep/store their coffee/tea mixture?  I like to keep it to use again later, but mine is always growing mold.

Since I've been mixing lemon juice in my coffee, it has yet to grow mold.

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12 hours ago, Brian Dougherty said:

Wait, they allow tea-bags on your "island"?  I find that almost as astonishing as an Italian having access to Nescafe :blink:

 

Does anyone else struggle with trying to keep/store their coffee/tea mixture?  I like to keep it to use again later, but mine is always growing mold.

Keep your coffee in a cool dark place or in the fridge. It doesn't have to be boiling, but it does work better at room temp and above.

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Thanks for all the thorough replies, i really appreciate it! I've been busy so i havent tried anything yet.

Mixing lemon juice with the coffee seems like a nice idea. Then i dont have to wait allnight for it to etch.

As John suggested, gun bluing oil seems interesting, i might try that if i can find some.

I guess ill just have to try and see what works best for me

 

 

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Something I'm about to try that I learned about from another maker is a product called Gun Kote, used for customizing metal gun parts.  Basically, it's a bake on spray paint (apply with an airbrush, and bake at 325F for 1 hour).  They have all sorts of colors, but the MS I know uses black and satin clear.  Basically, etch a slight topography, spray with black, bake on sand the highlights shiny, then re-coat with the clear.  It's questionable if it's considered food safe, but he does it on his hunters, EDCs, bowies, daggers, etc.  

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On 3/3/2021 at 8:15 AM, Brian Dougherty said:

Does anyone else struggle with trying to keep/store their coffee/tea mixture

I just have mine in an plastic gallon milk jug out of the sun for the past 5 years, but I live in the PNW so not too many hot days in a row and the nights cool pretty well, unlike the midwest...

 

Edited by billyO
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On 3/4/2021 at 6:16 AM, Paul Carter said:

I use half a bottle of instant coffee mixed in about a jars worth of water, then I add some lemon juice to it. Coffee by itself would take an hour to hour and a half but with lemon juice it cuts the time down to about 15 minutes. They come out dark.

Since I've been mixing lemon juice in my coffee, it has yet to grow mold.

 

On 3/4/2021 at 6:04 PM, Cory LA said:

Keep your coffee in a cool dark place or in the fridge. It doesn't have to be boiling, but it does work better at room temp and above.

Two really helpfull comments  that will certainly be put to good use. I have a fridge in my shed for the stabilising resin so have ample space in it for the coffee and with lemmon juice in to aid in the etch will make a difference to the process.

appreciate the advise.

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Just thought I'd add another option here.  Something I'm just now trying that I read about on another forum, but should work really well called Gun Kote from KG enterprise.  It's a bake on enamel that is commonly used to customize gun parts.  Airbrush on, and then bake for 1 hr at 325F. 

For damascus paaterns, do the acid etching as normal to get some topography, spray with black, let dry and sand off the 15N20 (as normal), then spray with satin clear and bake on. 

Very dark dark, very nice contrast and should be very long lasting, but questionable food safe-ness.  

Edited by billyO
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On 3/15/2021 at 12:15 AM, Garry Keown said:

 

Two really helpfull comments  that will certainly be put to good use. I have a fridge in my shed for the stabilising resin so have ample space in it for the coffee and with lemmon juice in to aid in the etch will make a difference to the process.

appreciate the advise.

I opened the can of coffee/lemon juice I mixed up back in November, and it has a small spot of mold starting to form on the lid. When I kept just the coffee in my fridge, it would only last a few weeks to a month before getting moldy. Also, I find the coffee/lemon juice etch before I do a final temper, gives a rainbow of colors on the blade if I temper at 430° or more for a couple hours. Really gives the blades a unique colored look that I haven't seen anywhere else.

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