Ferric Etch- first time. Any benefits to it?

C

crazydad42

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Aug 12, 2012
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Did my first etch in FeCl. Cut 25% with water. Submerged for 10 min then soaked in water and baking soda. Rinsed in vinegar. It did the job but the metal had steaks. I wiped with mineral spirits first. Why would it be streaking? Also, when cleaning it off I got black residue everywhere. Is that normal?

Is there really any utility to etching or even blueing? Does it wear off quickly during use?
 
When you etch in still solution the particles that are etching away can slide down the blade creating streaks. I put an aquarium aerator with a bubbler on the end in the bottom of the tank. Think of it as scrubbing bubbles. :cool: Also I check every 5-10 minutes and scrub the blade down with 1500 or finer sandpaper. If you are rinsing in vinegar you are introducing another etchant on to the blade. Kill the Fecl with ammonia or just spray it down with windex. Ammonia is cheaper.

If you are etching a mono-steel blade there is little benefit. It does provide a surface that seems to hold oil better and prevents rust a little. The surface can be damaged easily but does bring out any hamon action. But a good Hamon polish would be better. The black is normal..
 
I etch all kinds - and lots of it - Damascus, hamons, San Mai, etc.
I never - EVER - clean my blades with anything other than Simple Green or Dawn detergent, rinse well with clean water and a soft tooth brush.
The thought of putting any kind of solvent on my steel makes me grit my teeth.
I've had more streaks and spots, etc. after using solvents, and have had nothing since stopping that bad habit.
 
What you want is clean steel. Solvents almost always leave a residue. Wassh well and rinse in hot water as Karl suggests.

About the streaks:
When the acid reacts with the steel, gas bubbles form. These slide up the blade surface and "scrub" the black oxide off. This area etches deeper and the final result is streaks. The way to get a more even etch is to take the blade out one every minute or two and rinse well, wipe off with a clean paper towel, and put back in the FC. This will also make the etching go faster, as it keeps the steel exposed and removes the black oxide crud.
If you do a long etch without occasionally moving the blade, you can even get grooves in the surface.




My friend, Don Agee, uses this bubbling situation to his advantage when doing his makers mark. He finishes the handle, and then applies a resist in the shape of his logo to the brass, nickel, mokume, or damascus, butt cap. He then tapes around it with electrical tape ( to keep the FC away from the handle). He puts the butt in the FC just deep enough to immerse it. With the bubbles having no vertical surface to slide up, they sit there and get larger, eventually getting big enough to roll sideways and escape. While they are sitting on the brass, no etching happens in that tiny spot. He etches for a good long time, and the brass eats away as much as 1/16". This leaves his logo raised up with the background a moonscape of tiny craters. It looks like he carved his logo in for hours with a ball burr. I attached a photo of the effect. Some are much neater than tis shot, but this is what I had in my files.
 

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Makes sense. Does the etch hold on the blade even after use? Or does it wear off pretty quickly.
 
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