Problems with etching wootz
 

I'm etching this sword, but I am having some troubles. I followed all the instructions found here, and it works fine, I see the wootz pattern appear, and once I stop the etch, the blade just turns a dark grey color, and the pattern would disappear. I tried polishing the blade with a cloth and oiling it and cleaning this black residue that had built up on the blade, but still no luck getting the wootz pattern to appear again. Can some one tell me where I am going wrong?

Hi,
It sounds very strange, and I don't know if I can help you, but please tell us, step by step what you have done so far.
Jens

Thanks Jens, here is what I did:
1st I lightly sanded the blade by oiling it and rubbing it with a Scotch pad (green scab pads) then cleaned up the oil, and used another piece of pad with soapy water and cleaned the oil while sanding the blade more. once done I washed the blade with hot water to rinse and dried it off, by this time the blade was nice and smooth but it did show some pit marks. I tested with a weaker solution first slowly adding more acid until I could see the solution is getting the desired affect. By this time the blade was starting to darken up and the pattern was showing, all this time I kept the blade evenly wet with the solution. To stop the etching I used Windex for the ammonia, and then washed off with water immediately. I could see some yellowish orange color appear after the rinse so once I dried it I sprayed the blade with WD40. I wiped with paper towel to remove the gunk, and also used a nylon brush to clean up the gunk. I used a CLP to oil the blade and an old sock to polish, still going at it and still nothing.

Not sure if this helps but windex multisuface cleaner contains ammonium hydroxide ( aqueous ammonia) at only .1 to 1% solution most household ammonias have 5 to 10% ammonia in an aqueous solution. Could it be that at the lower concentration the pH is not high enough to stop the etching acid quickly and the reaction is continuing ? Just a guess and suggestion. Oh and if you are using the outdoor muti-suface-concentrated cleaner it has no ammonia but I still alkaline due to the sodium carbonate

Similar problems
 

Hi, This sword had not been etched previously and showed no pattern. A phosphoric etch showed promise, but on cleaning nearly all contrast faded away. If your etch is too concentrate you get that blacked scorched effect.
I found on such low contrast I had too go with that and polish lightly with Brillo
pads both regular and non scratch followed by Maas a polishing compound and lightly stop at desired effect. currently still working on this one to even it all out. Keep going but watch out to avoid excessive pitting. Steve

Oh, when polishing out after etch wash blade frequently with a good grease cutting soap material polished off will give a false contrast.

hello together
the etching of Wootz I use ferric III chloride and proceed as follows:
Polishing the blade with sandpaper to 600
Clean the blade with soap water
cleaned with acetone
Try concentration of the etching agent.
Coat the entire blade
stop immediately, cleaned with water
repeat this process repeatedly until correct score is ok.
I had already wootz, which was dark gray now!
More dilute etchant. this wootz was closing very bright! was an Indian Kard blade.

The Windex I used say it has ammonia-D, I used the same process with 2 other knives one wootz and one not, with those the result was normal. I guess my next step if using Brasso or something to try and polish it.

This will sound strange as the name says ammonia-D but windex with ammonia D does not seem to contain much if any ammonia. Welcome to marketing and trade names. Ingredients listed are Water, Isopropanol and Ethyleneglycol Monohexylether. It is still possible it has some aqueous ammonia ( ammonium hydroxide) as 29CFR1910.1200 the hazcom standard, pre GHS, did not require ingredients less than 1% to be listed ( 0.1% for a carcinogen) . But it would not be much. Still a pH that is alkaline 10.5 - 11.5 so it would neutralize an acid but if it is a weak base the reaction would be slow and that may cause problems as a stop bath.

MSDS here
http://www.btps.ca/files/PDF/MSDS/Windex_Ammonia-D.pdf

Even the "superconcentrated" only has 0.1 to 1.5%

http://www.centralstatesbus.com/MSDS...oncentrate.pdf
No idea why it worked before and did not now unless the etching acid was a lower concentration before and the alkaline in the windex was enough to neutralize the lower concentration acid. Still just a guess.

Another etch in progress
 

Hi, A second etching victim this one is again low contrast. Etching produced the blackish areas probably where this extremely thin blade was tempered for strength. This is second or third etch per each side. At first it came out very crystalline looking. I cheated and besides the polishing compound used the well worn 1500 and 2500 sand paper used initially to polish the rusty blade. Go slow without to much pressure. You might give us some photos, good luck. Steve

Any future etching will be with a more diluted etch.