Muriatic Acid for hamons?

i4Marc

i4Marc

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Oct 19, 2011
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I know a variety of things can work from lemon juice and vinegar to FC but I was curious if anyone has experience using Muriatic acid for the etch? If so, any recommendations for water mix ratios, dip times etc?
 
Hmmmmm, I did a search and found out it is fine for HC blades but the effect is a bit different from FC. Another question I have for the more knowledgeable here is, can Muriatic acid and Ferric Chloride be mixed in a solution safely? Also, I read that Muriatic acid will give a deeper etch but lighter? And I saw a question asked that I don't think was answered which is this: Can Muriatic acid be used for a deeper etch and then Ferric Chloride used over that for a darker etch?

And....... What is the approximate grit value of Flitz polish?
 
Why would you want to mix acids?

I don't believe Flitz has abrasives (silicone carbide, aluminum oxide) common to the grit systems that we typically use. It's a non-abrasive polish that doesn't work well on hardened steel unless you are buffing off light oxidation. People have tried stropping with it, but you're better off with chromium oxide, or other compounds commonly used for knife making, restoration and sharpening.

http://www.flitz.com/flitz-polish-paste/
 
Muriatic acid (hydrocloric) is actually an acting ingredient in the ferric chloride pcb etchant you buy. You can actually wake up 'dead' FeCl with a splash (not literally, n ever splash chemicals...) of muriatic. Powdered FeCl can be purchased however as a homogeneous mixture.

It will reveal a hamon or more acurately a hardening line, there just will not be the contrast of light and dark. To get the ashi to show up you have to polish. It is a process....

FeCl reacts differently with hardened and unhardened steel in a blade thus resulting in the dark coloration on a hardened steel blade and a light grey on the other.

Overall though, you want a slow etching process. The old adage is true, you can always take away more steel but you can't put it back. You want to be able to monitor the process closely and see the results start to appear. There was a good WIP type thread on this just a day or two ago. It was basically how I etch blades as well... at least with FeCl.

This probably isnt the best example of a good hardening line but is right out of the FeCl diluted with distilled water. 3:1... only a light scrub with 0000 steel wool was done. On my edc blades I go for a fully hardened blade as opposed to a differential hardening. Much polishing left to do. BTW, it is important to measure and mix precise quantities of this stuff. You want it to be repeatable, and know what effects adjustments made on the final product.

210c8df42ef031b9636953a03e163c4d.jpg
 
Another thing you can do since acids react differently to the steel is first etch with FC then polish some and then etch with say vinegar. The vinegar brings out the lighter colors more so then the FC does. Takes alot of experimentation.
 
HCl is used in etching hamons......but it is used at 100:1 dilution. It would ruin a hamon to use it at any normal strength. At that strength, it is weaker than lemon juice.
1cc Muriatic acid to a 100cc (1/10 liter, or half-cup) of water is what you want. Easiest way to measure without the right equipment is to put the container of 100cc water on a gram scale and add 1 gram of acid.
 
Great info guys. thank you. Let me get a bit more specific now. I am getting set up to do the etch right away so I want to get this right. I'm building the dip tube today and will be ready to start as soon as that is done. My blade is 80CrV2 sanded to a clean 2500 grit. The blade was edge quenched so I have a smooth quench line without any cloud-like activity. If the HCl at the strength Stacy suggests is weaker than lemon juice would it be safer or easier to just work with lemon juice, or vinegar? I would like the most dramatic contrast I can get so which chemical or progression of subsequent chemicals will help me achieve that? FC, HCl, lemon juice or vinegar?
 
I do a vinegar etch first, the I switch to lemon juice. I find the ashi pops best after the lemon juice etch. Its more subdued with just the vinegar. IIRC, there are as many ways to bring out a Hamon as there are makers making knives with a Hamon. :) Experiment and find what works.
 
Something else to learn- you can't polish without abrasion. Therefore Flitz is full of s---z!
That is the main reason I never recommend it to anyone-though it's an OK polish.
Simichrome is finer and is the industry standard metal polish.
 
i4Marc said:
Great info guys. thank you. Let me get a bit more specific now. I am getting set up to do the etch right away so I want to get this right. I'm building the dip tube today and will be ready to start as soon as that is done. My blade is 80CrV2 sanded to a clean 2500 grit. The blade was edge quenched so I have a smooth quench line without any cloud-like activity. If the HCl at the strength Stacy suggests is weaker than lemon juice would it be safer or easier to just work with lemon juice, or vinegar? I would like the most dramatic contrast I can get so which chemical or progression of subsequent chemicals will help me achieve that? FC, HCl, lemon juice or vinegar?
Click to expand...

Again, you WANT weaker than lemon juice IMHO. Straight lemon juice and vinegar are actually pretty strong. (Get some litmus strips if you don't believe me.) I dilute even vinegar when I am using it on polished metal. You will be surprised how quickly you will get a reaction even diluted.

A hamon should be just visible, but not so deep that you can drag a fingernail into it. On a 2500 grit surface even the lightest etching will be visible.

I don't do a lot of hamons so I cant give you a step by step, but I have been shown several times by a couple of others. One of the repeating themes was a little bit of etch followed by a lot of polishing. Then a little bit more etch followed by even more polishing. This seems to bring out the most detail as it allows the hamon to develop while carefully watched by the maker. A quick and aggressive etch was exactly what was being avoided. It was described to me like this.... Take two sugar cubes. Drop one in a clear glass of cold water. Drop the second into a clear glass of hot water. Then watch how they dissolve. The sugar cube in cold water dissolves slowly and evenly. The hot water eats away quickly and chunks begin to come off, not very even at all. Hot water is your strong acid, cold water your diluted acid.
The end product was a stunning line with ghostly wisps, dark and light contrast, etc.

FWIW, just edge quenching a blade will give you a quench line. It takes clay to form a very wispy and detailed hamon. Clay and a lot of patience and practice...

And like quint said, play with the different etchants on some scrap steel. There are a few makers who put some awesome textures/appearances on blades by using everything you'd find in a fast food restaurant and then some on a blade...

Thank you for the compliment Striga.
 
A cool effect although not totally related but kind of, saw a guy that took a kitchen blade I think it was and layered thinly sliced grapefruit on it. Let that sit I think over night but its been a while. Had some really cool looking etching going on.

I use a mix mash of things depending on the hamon and on how much I polish it out. Say you want a working hamon with just the basic effects so more like your 80crv2. You can take that to a lower grit say 800grit, etch in FC by dipping and then wiping with makeup remover pads, dipping and repeat. Once you have done that a few times take it out and carefully polish. I use several different polishes/scratch removers.
For a nicely detailed one I will sand to like 2000-3000grit then take my makeup remover pads and dip them in the FC solution then lightly rub the blade to start bringing out the hamon. I will go back and polish lightly with one of the polishes. Once that is done I clean it again then take another pad and use vinegar and start rubbing the hamon out with that. This usually accents the whispy lines and what not. Light polish after that then hopefully I am done.

Your work area must be very clean, wear fresh latex gloves or equivalent. As Stacy and others have said in other threads, cleanliness is one of the keys to a good hamon. It is amazing how easily a piece of grit can get on your work then your screwed and have to go back.

Just a brief overview of some of my procedures picked up from several guys here on the forums.
 
Ok. I think I'm going to go with alternating diluted applications of vinegar and lemon juice. Between each of these applications I'll polish with Mother's mag and aluminum polish. Can't seem to find Simichrome or Flitz in my area. If anyone feels Mother's is a mistake let me know. I also ordered some 1500 grit silicon carbide powder.
 
I had a really nice one once, worked on it a long time to get the Hamon perfect . I sent it to my Inlaws as a Christmas present. The wrote back " love the knife, but it took for ever to get that stain off of it!"
 
I finally found 1500g powdered abrasive on ebay. I have been using 3M rubbing and polishing compounds in the interim, and they have worked OK.


This was accidental in 15N20 at 400g with a light vinegar etch to get a bit of contrast:

10830896654_9bb997db9c_c.jpg


The larger knife is 1095, and the activity didn't show in my lousy pics, but both of these knives showed a lot of potential by the tim ethey got to 400g. If its there it will show early in the sanding.

11039424024_067d5c5a30_c.jpg
 
i4Marc said:
Jim,

Are you kidding? My jaw dropped in horror when I read that.
Click to expand...

Ya just couldn't resist.
But that's about what I thought many years ago when I saw my first one. Is aid to myself if that guy is such a master blade smith why doesn't he do a better job polishing. Haha
 
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