WIP - Making the "Coppadashi"

Rick Marchand

Rick Marchand

Donkey on the Edge
Moderator
Joined
Jan 6, 2005
Messages
9,680
It's been a while since I posted any wip's. There is not much to this one. The idea popped into my head yesterday (inspired by Scott Roush) and grabbed the camera before heading out to the shop. I only had the presence of mind to snap a few pics(one, very much out of focus) but you get the idea.

I started with a piece of 1084FG, 1/4" x 1/2" x 3"...
IMG_0028-11.jpg


Add heat and hammer blows...
IMG_0030-4.jpg

IMG_0031-6.jpg

IMG_0033-3.jpg

IMG_0035-5.jpg

After a little more refining to thin the bevels...
IMG_0034-5.jpg


I chewed off a couple pieces of copper..
IMG_0037-8.jpg

and placed them on the the blade (sorry for the pic... it makes my eyes itch)...
IMG_0038-6.jpg


I apologize for not getting shots of the next step but I needed two hands and it happens quick. Without a photographer, I was SOL... so let me break it down for you. I heated the whole blade to the melting point of copper(just past 1900F). Once it started dancing around, I used a poker to spread it like butter on a pancake. I repeated this for the other side. This was the result...
IMG_0039-7.jpg


After that kind of heat, a few normalization are in order to right the wrongs and refine the grain.
IMG_0036-6.jpg


I am kicking myself for not capturing the heat treat. After normalizing, I drilled the tang hole and stamped my name/logo. Then I clay coated the spine, leaving about 3/8" of the edge exposed. I then ran it through the forge and oil quenched. My reasoning for the clay was to reduce the chance of blowing the copper off during the quench. My previous experiments showed that it could happen if over heated. I got lucky!! Here is the heat treated blade.
IMG_0041-9.jpg

Yes, my name is crooked... look away, if you must...
IMG_0041-001.jpg


The next installment will be sanding in the edge and making the handle.

Thanks
Rick
 
Last edited:
It's a curious project. I'll be watching. I'll also be wondering how this blade will develop patina over time...
 
Way cool Rick. Ever since I saw Scott Roush post up his copper clad 'dashis I have been wondering the exact process of it. Gonna be a good looking blade for sure! During HT, the copper that doesn't blow off in quench, does it cool fast enough to actually anneal it? Making sanding easier with the copper?



-Xander
 
Thanks, Xander.... I was trying to remember who that was with the copper splattered 'dashis.... I will have to add an inspiration credit.
 
Rick, I know you've gone over this before but just real quick: what clay mix do you use?
Thanks,
Andy G.
 
I like your anvil. What kind is is. I know it is off topic but heck it was cool also. I will be watching the progress. Its a good idea for a unique looking blade.
 
Ver cool WIP. I'm curious how this will look once cleaned up.
 
Looking really cool, I had some ferric that I cleaned copper with that would do a similar thing. Kind of electroplate the blade.

Looking forward to more progress pics!
 
Very cool effect. It´s when I see something like this that I feel restricted by only doing stock removal.

Brian
 
Fellhoelter said:
No expected issues from galvanic corrosion from copper in direct contact with steel in this manner?
Click to expand...
I suspect there is potential for something, Brian... to what degree, I don't know. My biggest enemy would be electrolytes. That is part of the reason for this experiment. I have a few more that I did several months ago and there is no visable corrosion or separation. I have a big ol' chopper blade that I use quite a bit in wet acidic conditions. The guard is copper and i have not seen any corrosion. Mind you, the connection is sealed with epoxy/JB weld.... It will be interesting to see what the high heat fusion of copper and carbon steel will do.

Maybe I'll speed it up with salt water to see what comes of it. Thanks for bringing this up.
 
Fellhoelter said:
No expected issues from galvanic corrosion from copper in direct contact with steel in this manner?
Click to expand...

Exactly!....??

I know of several makers who do this technique with amazing results. But, I also followed a forum discussion on this copper/steel corrosion topic just a short time ago. So, that got me wondering the same thing as Brian.

Thanks for taking the time to do this Rick. Its wonderful to see how various makers ply they're trade.

Peter

Edit to add: Rick posted just as I did. Thanks Rick.
 
Three conditions are required for galvanic corrosion to proceed...

- the two metals must be widely separated on the galvanic series
- they must be in electrical contact
- their surfaces must be bridged by an electrically conducting fluid.

Removal of any of these three conditions will prevent galvanic corrosion.

So my question is... does the fact that these metals were fused at high heat negate the last condition of a fluid bridge? I can't recall ever seeing a blade rott off from a copper habaki/guard.
 
Rick Marchand said:
So my question is... does the fact that these metals were fused at high heat negate the last condition of a fluid bridge? I can't recall ever seeing a blade rott off from a copper habaki/guard.
Click to expand...
ACME = Anode, Cathode, Metallic Pathway and Electrolyte.

No, I believe the method you fused them with will not negate the last condition, but most definitely assures that the first 3 are met.
As soon as you have an electrolyte touching both metals, you have met all 4 requirements.

I don't know that you will have corrosion, or even necessarily expect that you will, hence my original question.

Regardless, it looks really cool...
 
You must log in or register to reply here.
Back
Top