I have used coffee on SS/HC San Mai. I have never had it yellow though. I don't have a lot of experience with this combination. Maybe Karl or Ed can chime in.

A photo might be nice though......

Karl is certainly more of an expert on SS San/HC San Mai than me, but I have done a good bit of it.  Personally, I'm not a fan of the coffee etch, for me it's far less trouble, and far better results to etch with Ferric Chloride.  

  I have seen the "yellowish" with coffee etch, and it's one of the many issues that makes me dislike it.  I've seen/had it happen not only on SS/HC Sa Mai, but also on my typical 1080/15N20 damascus.    Based on my experiences and comparisons between coffee etch and Ferric Chloride, I'd take Ferric Chloride every time..... and twice on Sunday.  😉   

Thanks Ed! 

Have you ever tried baking the blade at 200deg or so for a couple of hours to help bake in the finish? I read on here somewhere that might make it more durable. 

I agree with Ed. I don't use the coffee on anything.

I tried it a few times.

It certainly makes things black! But - you can rub it off with your thumb.

I etch my SS San-mai but only clean off between cycles with the soft make-up removing pads. This lets the black build up nicely. I do three or four etches about 15 seconds each time. Neutralize and let dry. Later I give it a good dose of RIG - Rust Inhibiting Grease - from Brownells. It's under a new name now, but still the same product.

Also significant to the result is the steel types of the core. Mine is some 20 year old 1095 that had a significant amount of manganese, which helps it to etch dark.

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Posted by: @shane-atwood

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Thanks Ed! 

Have you ever tried baking the blade at 200deg or so for a couple of hours to help bake in the finish? I read on here somewhere that might make it more durable. 

  I have tried baking the coffee finish on... it didn't make much difference for me. 

For a number of years now, I have been using clear Gun-Kote on blades.  It started out with a couple of good clients asking me if I could come up with something that would help reduce the maintenance/care required for Damascus blades.   

  After some trial and error in how to apply it, without it looking like the blades were coated in plastic, I got it figured out, and have been using it ever since.  I coat Damascus blades (including San-Mai blades) after etch, but before assembly, and on those blades using synthetic handle materials such as micarta or G10, I coat the entire finished knife with a LIGHT coat of satin clear, and it's proven to be a real game changer for blades/steels that once required significant care to keep looking good.  😉 

Shane when I do my coffee treatment it's usually under 4 hours and I usually pull the blade out every 15-30 minutes depending on how it's taking. When I pull the blade out I rub the areas I don't want dark with some worn high grit paper usually less as time goes on. Here's a shot of a stainless clad blade and a knife I've been using probably at least 4 times a week since February. 

Here's the stainless clad blade. 

Wow, looks like I have missed some discussion here. Thank you all for chiming in and sharing your thoughts. The blade I have been working on I finally just went with a straight up acid etch. I had polished and ferric etched and coffee etched this blade several times trying to get a decent finish. I was never happy with, but I think it looks pretty good now. 

Karl, those are absolutely amazing!! That is some killer San Mai! Love your blades!

Here are a couple pics of the finished blade. I would be interested in learning more on your ceracote process Ed. You've always been a big inspiration!

Off Side

The Old forum had more restrictive file sizes, our new forum not only allows a little more size freedoms, it also will simply limit the uploads automatically.  That is my fault for not informing everybody about the added file size freedom and I apologize, but I need to thank our moderators for their continued diligence and willingness to help all.  It is indeed currently set at 1 MB base upon the recommendations of our server host.  So all is good, don't worry, just have a nice chat at the new ABS Forum.

Posted by: @karl-b-andersen

I agree with Ed. I don't use the coffee on anything.

I tried it a few times.

It certainly makes things black! But - you can rub it off with your thumb.

I etch my SS San-mai but only clean off between cycles with the soft make-up removing pads. This lets the black build up nicely. I do three or four etches about 15 seconds each time. Neutralize and let dry. Later I give it a good dose of RIG - Rust Inhibiting Grease - from Brownells. It's under a new name now, but still the same product.

Also significant to the result is the steel types of the core. Mine is some 20 year old 1095 that had a significant amount of manganese, which helps it to etch dark.

 

Hey Karl, I keep coming back at looking at your blades. They are amazing!

I am assuming you mig weld all the way around your billet in the beging to sill it up. At what point do you grind your weld away? 

Posted by: @shane-atwood

Hey Karl, I keep coming back at looking at your blades. They are amazing! I am assuming you mig weld all the way around your billet in the begining to seal it up. At what point do you grind your weld away? 

I don't do mine like that. I only have an arc welder. Just think "oxygen free".

I first saw this demonstrated with the billet stuck inside a short piece of scrap tail pipe with the ends crimped. A piece of "something" - I do forget what - was put in the pipe to consume the oxygen when it got hot.

I create my own "container" that I do just keep to myself.

I do use 1/4" jacket pieces and 3/8" 1095 for the core. I just use a few tack welds to hold the pieces together. Put in my "container". Place in the forge and let soak for 15 minutes - press the whole billet in one squeeze on the press.

I re-heat a few minutes and press again.

Then I grind any weld off to ensure good welds. (I've been doing this for over 10 years and have only had one bad weld.)

I have infinitely adjustable stops on my press so I slowly reduce the billet in 1/16" reduction steps with flat dies until my final thickness. On my next-to-last heat I run through the press with drawing dies to upset the billet to give it the ladder effect on the bottom of the jacket edges.

Then one more final heat with flat dies to final thickness.

Then to the surface grinder.