Even wootz blades can break

Jens Nordlunde · 11th April 2005, 06:28 PM

Hi Tom,

I am not sure that I agree to this, but I will have to come back to it later, as I don't have any more time at the moment.

Jens

tom hyle · 11th April 2005, 06:41 PM

Thanks. I don't mean, BTW, to imply that when well made, they are especially weak; just I haven't heard they are extra-strong.

Gt Obach · 11th April 2005, 10:03 PM

Hi Jens
if you have a sort of blotchy area .....it can sometimes result from the way the blade way polished.... I find to get a decent etch you have to avoid burnishing the metal... this is why I like to use abrasive with a lube to wash away the cuttings...... if you load the abrasive up with metal it will intern burnish the surface and make the etch results inconsistent.
-- it is somewhat the same as polishing a japanese sword.... if you burnish the surface it will be extremely hard to see the hamon....

the blotchy areas can also be a result of overheating.... you can over heat a blade in local areas and it won't pattern as well..... or even loose pattern...... it could also be that there is a local area of decarburization... ?

-- sometimes you can have an incomplete melt..... by this I mean that all the charge ingredients you started out with aren't fully melted but are incased within the ingot...... this is a cruel surprise.... that you will only find out when you finish etching the blade at the end....

-- another critical problem is etching.... if the blade is not totally degreased.... and spotless.... you can have really weird streeks and odd irregularities
if your etch is not nice... then I think you miss the beauty of wootz...

I don't think of it as a super steel..... because it just works as good as my regular steel knives... but where it excels.....is the beautiful patterns.... and this is it's true magic

the above blade looks good..... it maybe that the steel was abit burnished in areas before the etch... (but this is just a guess)

the major blotches look like the blade was pulled out of the acid....and the drops of acid on the underside of the blade weren't wiped away.... so the drops kept etching...... this will give that blackened pattern...

- it doesn't look at all like cracking...... so it is a good blade

Greg

Jens Nordlunde · 12th April 2005, 02:42 PM

Thank you for your answers, it is most interesting.
Tom, I think that Indian blades famed by al-Biruni and al-Kindi back in the 8th and 10th century must mean something. They knew swords, probably used them too, so they would not fame a blade 'only' for sharpness, there must have been more to it than that, flexibility, hard to break, things like that. There must have been a reason why these blades were more expensive than other blades.

Jens Nordlunde · 12th April 2005, 04:56 PM

Her comes a recipe for quenching, but before I bring it, I think you should have a small lecture in botany. In the recipe is mentioned ‘Serpent’s mushroom’. As I did not know what it was I tried Google, with no result, then I read further and it said that it was the same as ‘Mountain celery’. That gave a result, 138 to more exact, and it also gave a lot of recipes how to use ‘mountain celery’ in different dishes, this was a surprise to me, as it clearly says that ‘serpent’s mushroom’ is fatal if eaten. Well I thought, it could be, that those dishes were only meant for nasty mothers in law – who knows?

The text below is from ‘Persian Steel’, the chapter ‘The Development of Iron and Steel Technology’, written by Dr. Brian Gilmour.

In the 9th century, al-Kindi wrote that ‘moderation of quenching is an aid to sharpness, for quenching, if intensive, causes the serving of the blade in adversity, in other words, that too sudden quenching, as in cold water, made the blade too brittle.

(Although I would like to put the whole book on the forum, I can’t – you will have to buy it – it is very interesting, and a god investment, I think. Jens). And now to the recipe.

‘Take the mushroom which is known as ‘serpent’s mushroom’, so called because it is fatal if eaten, and which is the same as mountain celery [sic]. It frequently grows especially at the foot of large olive trees or in asses’ dung. Grind it up, collect the juice of Persian alkali and the jujube, and vine lees, sea foam, sal ammoniac, canthardies, the juice of the tender henbane, grind the solid parts to a powder and mix them with the liquid, place them in a bottle stoppered at the top, and bury in manure for 40 days until completely dissolved. Then take felt, soak it for three days in old urine, dry in the shade, and sprinkle the abovementioned liquid upon it. Bring the sabre to red heat in the fire and spray it, using wool, as is done for sabre iron. When it has drunk, cool it, cover it to protect it from dust. It will cut anything, and if a saw is made out of it, it will cut through glass like another will cut through wood; this is a noble tempering.’

This suggests that Tom is more right than I, the sharpness was most important. But he also states that the blade should be right tempered – so I was also right

.

Ann Feuerbach · 12th April 2005, 06:25 PM

FYI...I disagree with Brian's translation...I think al-Kindi meant tempering and not quenching. As far as I understand, true quenching (heating to red heat and then emersion in liquid, produces martensite) was not done for crucible steel. No archaeological evidence for martensite and you would loose the pattern.

It is a great book

12th April 2005, 04:56 PM	#5
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,718	Her comes a recipe for quenching, but before I bring it, I think you should have a small lecture in botany. In the recipe is mentioned ‘Serpent’s mushroom’. As I did not know what it was I tried Google, with no result, then I read further and it said that it was the same as ‘Mountain celery’. That gave a result, 138 to more exact, and it also gave a lot of recipes how to use ‘mountain celery’ in different dishes, this was a surprise to me, as it clearly says that ‘serpent’s mushroom’ is fatal if eaten. Well I thought, it could be, that those dishes were only meant for nasty mothers in law – who knows? The text below is from ‘Persian Steel’, the chapter ‘The Development of Iron and Steel Technology’, written by Dr. Brian Gilmour. In the 9th century, al-Kindi wrote that ‘moderation of quenching is an aid to sharpness, for quenching, if intensive, causes the serving of the blade in adversity, in other words, that too sudden quenching, as in cold water, made the blade too brittle. (Although I would like to put the whole book on the forum, I can’t – you will have to buy it – it is very interesting, and a god investment, I think. Jens). And now to the recipe. ‘Take the mushroom which is known as ‘serpent’s mushroom’, so called because it is fatal if eaten, and which is the same as mountain celery [sic]. It frequently grows especially at the foot of large olive trees or in asses’ dung. Grind it up, collect the juice of Persian alkali and the jujube, and vine lees, sea foam, sal ammoniac, canthardies, the juice of the tender henbane, grind the solid parts to a powder and mix them with the liquid, place them in a bottle stoppered at the top, and bury in manure for 40 days until completely dissolved. Then take felt, soak it for three days in old urine, dry in the shade, and sprinkle the abovementioned liquid upon it. Bring the sabre to red heat in the fire and spray it, using wool, as is done for sabre iron. When it has drunk, cool it, cover it to protect it from dust. It will cut anything, and if a saw is made out of it, it will cut through glass like another will cut through wood; this is a noble tempering.’ This suggests that Tom is more right than I, the sharpness was most important. But he also states that the blade should be right tempered – so I was also right.

11th April 2005, 06:28 PM	#1
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,718	Hi Tom, I am not sure that I agree to this, but I will have to come back to it later, as I don't have any more time at the moment. Jens

11th April 2005, 06:41 PM	#2
tom hyle Member Join Date: Dec 2004 Location: Houston, TX, USA Posts: 1,254	Thanks. I don't mean, BTW, to imply that when well made, they are especially weak; just I haven't heard they are extra-strong.

11th April 2005, 10:03 PM	#3
Gt Obach Member Join Date: Mar 2005 Posts: 116	Hi Jens if you have a sort of blotchy area .....it can sometimes result from the way the blade way polished.... I find to get a decent etch you have to avoid burnishing the metal... this is why I like to use abrasive with a lube to wash away the cuttings...... if you load the abrasive up with metal it will intern burnish the surface and make the etch results inconsistent. -- it is somewhat the same as polishing a japanese sword.... if you burnish the surface it will be extremely hard to see the hamon.... the blotchy areas can also be a result of overheating.... you can over heat a blade in local areas and it won't pattern as well..... or even loose pattern...... it could also be that there is a local area of decarburization... ? -- sometimes you can have an incomplete melt..... by this I mean that all the charge ingredients you started out with aren't fully melted but are incased within the ingot...... this is a cruel surprise.... that you will only find out when you finish etching the blade at the end.... -- another critical problem is etching.... if the blade is not totally degreased.... and spotless.... you can have really weird streeks and odd irregularities if your etch is not nice... then I think you miss the beauty of wootz... I don't think of it as a super steel..... because it just works as good as my regular steel knives... but where it excels.....is the beautiful patterns.... and this is it's true magic the above blade looks good..... it maybe that the steel was abit burnished in areas before the etch... (but this is just a guess) the major blotches look like the blade was pulled out of the acid....and the drops of acid on the underside of the blade weren't wiped away.... so the drops kept etching...... this will give that blackened pattern... - it doesn't look at all like cracking...... so it is a good blade Greg

12th April 2005, 02:42 PM	#4
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,718	Thank you for your answers, it is most interesting. Tom, I think that Indian blades famed by al-Biruni and al-Kindi back in the 8th and 10th century must mean something. They knew swords, probably used them too, so they would not fame a blade 'only' for sharpness, there must have been more to it than that, flexibility, hard to break, things like that. There must have been a reason why these blades were more expensive than other blades.

12th April 2005, 06:25 PM	#6
Ann Feuerbach Member Join Date: Feb 2005 Posts: 133	FYI...I disagree with Brian's translation...I think al-Kindi meant tempering and not quenching. As far as I understand, true quenching (heating to red heat and then emersion in liquid, produces martensite) was not done for crucible steel. No archaeological evidence for martensite and you would loose the pattern. It is a great book