Question for the Hamon Chasers....

Horsewright

Horsewright

Knifemaker / Craftsman / Service Provider
Joined
Oct 4, 2011
Messages
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I've been making a lot of knives from 26C3 lately. I'm doing what I call a working hamon on them:

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First few batches I was pretty happy with them and how they were coming out:

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However, the last few batches I've been struggling with bubbles (I'm guessing) causing streaks and sometimes also eating into the polished part of the blade:

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I'm cleaning the blades with alcohol prior to etching. Whats happening and more importantly how do I prevent it?

I have etched a couple gillzion damascus blades without any of these difficulties. Thanks.
 
What are you using for clay?

Is it possible that the clay has bubbles in it?
I have no idea if that would cause what you're looking at, just throwing things out there..
 
Furnace cement. Don’t think so though. Some areas that aren’t getting the clay are also affected.
 
When etching do you see gas bubbles forming on the surface?
 
Haven’t watched that closely. Don’t know. Stick em in for 20 minutes or so and set a timer.
 
What kind of etch cycle are you using? I use FeCL. 1part FeCl to 3 parts distilled water. I etch for 25 seconds, dip in water and then quickly scub with 4 ott steel wool. I do this five times, then neutralize with windex and baking soda. Then quickly polish with 1500 silicon carbide mixed with 3 in 1 oil. I mean quickly. Maybe 30 seconds each side. For what I sell my blades for I don't care to spend an hour polishing each blade.

https://i.imgur.com/AqDVQta.jpg
 
Thanks! It must be nice to be smart.
Allen are you still located at Guadalupe Mountains National Park?
 
Tom Lewis said:
Thanks! It must be nice to be smart.
Allen are you still located at Guadalupe Mountains National Park?
Click to expand...

Hey Tom!
No I moved down to Big Bend National Park. How are things in Carlsbad these days? Hope the weather didn't mess you guys up too much a couple weeks back!
 
We have a wood burning stove so we were fine.
Horsewright, how thick is the clay you use? What temp do you quench at?
 
I've experienced these bubbles before when my etchant is of too high of a concentration.
Kind of like electrolysis with too much current. The bubbles form and stick to the surface preventing etchant from contacting the surface. Not saying this is what you experienced, just my observation that seems similar. Try diluting your etchant a bit.
I first noticed this when using fresh vinegar. Now I "season" it a bit by soaking some scrap steel in fresh vinegar to tone it down a bit.
 
I see two likely things.
One, you need to occasionally remove the blade, wipe it off, rinse it off, and put it back in the tank. If you don't little bubbles or other spots of oxide can form and make a stippled or "bubbled" look.
Two, for long etched to get a hamon, use diluted FC. I use 15:1 for etching a hamon. Even then, 20 minutes is a very long etch.
 
Thanks guys for all the info!

Tom Lewis said:
We have a wood burning stove so we were fine.
Horsewright, how thick is the clay you use? What temp do you quench at?
Click to expand...

Tom its about like yogurt. HT is out sourced so don't know on your quench question.

Got a batch to do today I'll let ya know how it goes. I like your system Tom, will be giving it a go. Kinda fits in with how I work.

Allen, we use to wholesale our sandwashed silk wildrags to Big Bend Saddlery in Alpine when we had reliable supplies of the special silk we use to make these. Use to sell a lot to them.

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I might mention the pad I use to polish the blade is "Felt Blankets" It is a "Self-Stick" piece. It is used to put on the bottom of furniture to protect whatever surface the furniture is on. I cut to size and stick on a wood backing. This allows me to really polish in a hurry.
I also put some "Flitz Polish" the green kind in with the Silicon Carbide and 3 in one oil.
Good luck, I hope this gives you better results.
 
Gotta say guys thanks! Did eightthe other day and not a single bubbly streak!! Perfect. Thanks again.
 
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