Muriatic Acid or Feric chloride??????

R

Rick Frigault

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Mar 9, 2000
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118
What are your opinions to using Muriatic Acid as an etchent on Damasteel as compared to using Feric chloride?

Or, what do you use to etch Damasteel, and the way you use it??

Thanks!!
 
Muriatic acid is "hydrochloric acid" (HCl) in a less pure and diluted strength for non-technical applications like cleaning bricks. Ferric Chloride is an iron "salt" of HCl that is nonetheless very acidic, though not as "strong" as HCl.

Either will etch any high carbon steel, eventually. It is a matter of strength and timing. Everyone has a slightly different dilution and technique. The keys are "pretty dilute" and "multiple, short immersions". Wash the black oxide off between immersions and perhaps brush lightly with non-abrasive kitchen Scotchbrite or 800 grit paper. Dilution should best be done with distilled water to keep it uncontaminated with water minerals. Beyond that it's a matter of experimentaion.

Either will do fine on Damasteel.

Hope this helps.
 
First you should talk to the customer and see if he wants high contrast or a more subtle contrast. Then play with the variables ; time , concentration of the solution and temperature . Going slowly and cleaning and checking often is the way to go as fitzo suggests.
 
You can start with a 50/50 dilution. That works for many. Some go as high as 5 parts water to 1 part FE. :eek:
 
With Damasteel the two give much different results.

Ferric will result in a double grey pattern (dark and light grey pattern) on either a matte or polished finish. Makes the material look like carbon steel damascus.

Muriatic will give a mirror/frosted finish on a polished finish and a lighter grey/grey pattern on a matte finish.

Either can be used to very heavily etch then the material can be polished to give a stepped surface.
 
George pretty well summed it up. I have always liked Muriatic for Damasteel but tastes are different!
 
George, do you feel that difference is regardless of dilution and "slowness" of etch?
 
Dilution has never been a concern as far as I am concerned except in determining the amount of time in the etchant. The more dilute the longer the etch takes.

Agitation however makes a big difference in time required and consistancy of etch.

I prefer the mirror/frosted finish that muriatic acid gives Damasteel. After all why pay the price of stainless/stainless damascus and not show it off to it's full potential?
 
Interesting, George, and thanks. "Theoretically", at least, the more dilute the acid, the more different the rates of etch between the two steels will be. While that's the theory, how much it has to do in the real world is always a question. Also, it seems the "coloration" will be different for different acids, also, regardless of concentrations, based on what I understand here. I go about it dfferent from you, so this is an enjoyable interchange.

When I was first taught to etch damascus, I was told to frequently wipe the blade with a feather, of all things, to remove the bubbles that formed during the reaction. I would think the agitation does that, along with keeping the etchant "fresh" at the steel. Nowadays, I remove frequently, and scrub with a piece of steel wool.

I always enjoy it when a little bit of chemistry sneaks it's way into knifemaking. I find these topics far more enjoyable than the now past days in the lab...
 
Pretty much as advised above, Bruce Bump has tought me to mix my etchant 3 parts distilled water to one part ferric chloride. Etch five minutes and scrub down; repeat until statisfied with the results (four or five cycles). Buff with 0000 steel wool between 5 minute etchings and then finish after final etching with 1500 to 2000 grit paper. A light final buff with white buffing compound without over doing it.

I will not blame Bruce for the words written below. Those are mine and my opinion only:

For a full tang damascus, resist coat the handle and guard/bolsters prior to etching and soak the handle area in acetone to remove resist after etching. However, before removing the resist soak in ammonia to neutralize the etchant. If the resist was not compromised during etching the ammonia will not soak into the handle material. The fumes from the ammonia may attack the guard/bolsters but the effects of that can easily but carefully be buffed away.

RL
 
Well!!!!!

What does one do!!!!

I did go with muriatic acid! Thought I'll give it a try!!

I did like the out come! But!!! There were parts of the handle that were polished that I did not want etched! So I put nail polish over the spot that would be in the acid (like I would do with the feric chloide), but it didn't work.
There were way more fumes than I thought there would be, and it melted away the nail polish where I didn't want etched. Also the fumes etched the polished parts that were NOT in the acid, which I did not know would happen, so I had to repolish.
The contrast was not as much as feric chloide, but a much deeper etch and a lot faster.

Has anyone tryed to do the muriatic, for the deep etch, then go to the feric chloride for the darker contrast??

Maybe I'll try that next!!

Thanks for all the great info!!!!
 
How much did you dilute the muriatic acid? Does it have a "%HCl" on the bottle?
 
I 'most never fool with damascus, but I did etch a small blade one time in a pyrex lab beaker of Muriatic acid heated to boiling with a propane torch. :eek: It etched beautifully in about a minute. :D
 
That's where the fuming problem and such comes from, Rick. Way too potent for what you need. I'd say try it at 1:10 next time, diluting with distilled water. Be careful how and where you store that stuff, or it will rust all the tools in your shop. Hydrochloric acid is notoriously tough to contain.

I read somewhere that printed circuit board etchant is only like 3% ferric chloride, and most of us dilute that.
 
fitzo said:
That's where the fuming problem and such comes from, Rick. Way too potent for what you need. I'd say try it at 1:10 next time, diluting with distilled water. Be careful how and where you store that stuff, or it will rust all the tools in your shop. Hydrochloric acid is notoriously tough to contain.

I read somewhere that printed circuit board etchant is only like 3% ferric chloride, and most of us dilute that.
Click to expand...

also remember, always add the acid to water not the other way around
 
OK!!

To dilute or not to delute????????

Other then the fuming that caused me a bit of a problem, ( if I knew, I would have been ready for it), why dilute???

It goes back to what George said earlier!! It only makes the etching take longer!!!!

WHY DILUTE???
 
The more dilute the acid the more different the rates of etch between dissimilar steels will be.
 
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