Etching wootz, opinion needed.
 

I am once again in need of assistance when etching. I have etched an indian sword in my possesion. I have etched with ferric chloride at about 30%. The sword etches very quickly, about 5-10 seconds will give it a good dark etch.

Now to the problem. There is an area that etches diffrently then the rest of the sword (see picture) the area is on both sides of the sword. I tried ligthly polishing it and the etching again, and repeated three more times. But the result was only slightly better.

I do not think it is a forging flaw. Maybe some result of heat treatment, but the why would the are around it be lighter.

I am thinking that maybe there was rust on the blade and someone sanded away the rust and this is why it looks this way.

I was thinking that if I polished the blade with starting with a rougher polishing paper 400 then upp to 2000 the blade would etch lighter but more uniform. BUT since I dont really know that that will work I am unvilling to try.

I know that there are members on this forum that has had a lot of experience with etching and I am hoping that someone has encountered something similar and is willing to share there knowlege. So In your opinion should I just leave it as is or is there a way to etch it more uniform. If I polish the etched blade it the flaw will become allmost invisible while the pattern is still visible. But we all want that dark etch, dont we :)

Hello,

I encountered exactly the same problem a few times already. I tried etching with Nital, FeCl and even with a dilution of Perma Blue but the faded areas would stay the same.

My conclusion is that the difference is caused by some kind of heat treatment that affected the structure of the wootz. :shrug:

I am attaching some photos of a Persian Kard displaying the same problem. I also have this on a Persian Shamshir.

So my opinion is that you should leave it as it is.

To what grit did you polish the sword before etching?

Regards,

Marius

As a knifemaker I do not use iron3chlorid anymore. I hate that. Every little difference in degreasing and difference in heat-treating is visible and any micron rest of the acid will result rust. After lots of oil you can have a red rust if you do not take care.

I have etched some pieces of wootz with nital, which works well. Instant coffee makes a good black colour and from my experience its makes a more ph-neutral surface which will not rust so easy.

At the end I have etched some hundred blades of different damascus-steels and every blade was different. Sometimes there were great different results even if the steel was from the same billet. There was often a situation that I decided to grind the etch away and to do everything again and then the result was much better. Every none uniform quenching will result clouds in the etching (You can name it hamon when itˋs under control )

With that now visible areas on your blade it will be difficult to get a better result without grinding everything away to a shiny bladesteel. So every blade is different and it will be difficult to give you a receipt that will work 100%. Try out only light etching which will not remove much of the steel. Grind a small area with 1200 grit shiny on your blade were it is bright and dark together and try nital with some drops. Maybe you will find a solution that will work. Good luck

Best Thomas

Thank you Marius and Thomas for your replys.

I polished 600 grit to 1200 grit to 4000 grit polish paper on this one. The first etching was with lemon, that worked fine. But since it showed this area of bad etching I repolished and etched the last 1/3 of the sword with ferric chloride just to see if it produced a better result on the problem area. It did not.

So I have to repolish and etch one last time. I will most likely etch it with lemon. Ferric chloride give a darker pattern but I agree with Thomas, Ferric is not fun to work with and I have had problems getting good etchings on other blades I have.

Thomas, I would love to try etching with Nital, but it is not possible to get it in Sweden.
I did not know that it was possible to etch wootz with instant coffe. I really need to give that a try. Approximately how long does it need to be emerged in the coffe for it to etch?

Thats a great looking dagger Marius, that chaotic wootz sure is facinating to look at.

regards
Peter

How do you do it with instant coffee?

Water and some spoons of instant coffee. It is a very slow etching. You can put a blade in for some hours without a big risk to remove too much steel. But it will etch to a deep black and you can feel a structure after a day on damascus blades. I use it everytime for damascus blades. Some weeks ago I have found a pamor lancehead on a fleemarket and the coffee worked better than ferric acid. To bring out a deep structure on my damascus I start with sulfuracid to „make the structure“ first. But the colour is often gray with that and the coffee afterwards brings out a deep black on the none nickelsteel. I do not know what the coffee makes with the surface. But the black colour seems to be relative stable against new rust. With ferric I have sometimes the first slight red rust after seconds and you are not fast enough with cleaning it. I have made some copper/iron mokume gane some weeks ago and the coffee is able to make the iron black without etching the copper. So it is a wide field for testing.


My experience with antique wootz blades is , of course, a minor experience. I do not have so much of them. 😢And as I said , each blade will etch different.
Hope I can help a little bit.

Best Thomas

Very, very interesting! Definitely worth a try.

Thank you! :)

Thanks!!!

Hi
There is tannic acid in coffee, and seemingly 30 other organic acids as well ( according to my quick google of “tannic acid in coffee”) I assume it is these that are doing the etching?
Ken

I know this is kinda old but I am getting ready to etch a possibly wootz blade with nital 3%. For those of you that use nital 3% what do you do afterwards? Baking soda or a acid neutralizer?

I use baking soda and never had any issues at all
best of luck
ken

Same here. Baking soda directly on the blade after you rinse it off in water.

Thanks. I'll take pictures and post one way or another.

Where did you get your Nital from?

I am desperate to get some but without any success.

Hi Marius
Why not make it yourself

it is just Nitric acid, Methanol/ethanol/or methelated spirits
I used work in a university chemistry department so i just made it myself, I have a thread on making it up on the forum

we conversed before on this

http://www.vikingsword.com/vb/showth...ighlight=nital


if you go to your local university or perhaps secondary school and explain what you want it for you may be lucky
I can explain process to you if you can get materials
regards

Ken

I have not received it as yet but ordered it here;

https://etchantstore.com/

Thanks for the link. That is one price mark up. I used be a buyer in a chemistry department so I know pricing.
Raw ingredients for 500 ml would cost under a dollar.

I wish I could make and supply the sword collector fraternity at cost.

Not being critical here just an observation.

Regards
Ken

Thank you very much for the reply! Unfortunately, they do not serve Europe.

Sorry to recommend the Etchant store. They only sell to commercial addresses. They are worthless for individuals.

It looks more and more like it's not just them. I cannot find any sellers that will sell it unless you have the proper identification/documentation. I even checked a welding supplier and was told they could not even get it. Does anyone know something that is available that is close to it? Vinegar does not seem to do the job. Thanks.

Since Nital seems next to impossible to come by; How well does Ferric Chloride do when compared to it?

Ferric chloride seems to be the next best alternative to Nital but
1. it is more difficult to work with as it tends to stain everything... including the sink;
2. the end result shows less contrast than with Nital;
3. it leaves the piece more prone to rust.

As with regards to the etchant store, they used to deliver to individuals until a couple of years ago. I particularly liked their 5% Nital that allowed me to dilute it down to 4% which in my oppinion delivered the best results.

Polishing thr surface to anything above 2000 grit (3000 in some cases) might be counterprodictive as the metal becomes so mirror-shiny that makes it difficult for the etchant to bite.

That looks very much like someone heated a spot on the edge, either to straighten a deformation, or in attempt to re-harden a spot.

This is quite possible. These white spots are result of overheating, either during or after forging. They become permanent part of wootz structure/pattern and once they're formed there is no way to 'remove' them by different etchants or develop better wootz pattern or contrast.

Highly likely.
European bladesmiths of the 19 century got plenty of wootz ingots and forged them into blades using European custom of heating the ingot to “ white”.

Surprisingly ( for them) the beautiful wootz ingots produced boring monosteel blades:-) Now we know why: at temperatures above ~850C dendritic structure just melts away and there is no way to restore it.

That raises another question: how did Persian or Indian masters managed to forge together 2 different samples of wootz to create scarf welding with only a thin line of amorphous steel as a scar?

Yes cherry coloured steel would keep the pattern.

Yes, but would it be enough to assure good forging?

I dont know. But I am sure that working cherry heated iren must have been quite hard - not that I have ever tried.

Maybe with a proper type of flux the scarf joint between the dissimilar steels could have been achieved.
I would imagine Ric Furrer might have some thoughts on the subject.

When I have etched a blade with Ferric chloride, I wash it , dry it with a heater, and while the blade is still warm I soak it in white vaselineoil and leave it for some time.

Due to restrictions in my country I cant buy nitric acid or Nital.
The other day I was testing to see if an item was gold using my gold testing solutions that I bought on Ebay some years ago. When reading the label on the bottles I realised that they all contain nitric acid. Label states.
1. 10k contain nitric acid
2. 14k carat contain Nitric acid muriatic acid
3. silver contains Nitric acid and Potassium Dichromate

Now this may be a silly question, but I have to ask. Do you think its possible to make a Nital like etching solution for wootz using the gold testing solutions?