A worthy kattar for comment

Ann Feuerbach · 16th March 2005, 06:43 PM

Hi Lew,
Yes the tannic acid solution does not make the pattern pop out as much, but from a conservation (museum) point of view, ferric chloride is not an acceptable method. Even with neutralization. With this process, we do not use water. I have also found a method to give a great golden sheen. I am still working on that one, but it is beautiful. 99% of curators would not let a conservator use ferric or nitric acid.
On another note, I have done extensive research on the different between wootz and pulad. It seems that the difference in the pattern is initally due to the fact that the indians take out the ingot while liquid and the solidification and cooling is very fast, which produces small dendrites. In the persian pulad process, they ingots solidify and cool slowly, thus producing large dendrites. From Verhoeven et al reserach, the cementite aligns along the impurities from the dendrite formation, thus big dendrites, coarser pattern vs faster cooling, smaller dendrites, finer pattern. However, final forging and trace and minor elements also plays a part.
Ann

Ann Feuerbach · 16th March 2005, 06:45 PM

Oh, I forgot, also the Persians added Mn to the mixture, which probably accounts for the darker phase contrast.

Montino Bourbon · 17th March 2005, 04:48 AM

Just a thought; what would happen if the ingot was allowed to cool in a strong magnetic field? Would the dendrites align with the field?

Something for the experimenters to try!

Ann Feuerbach · 17th March 2005, 02:49 PM

Interesting question. However I do not think so, if you look at castings, the dendrites grow from the outside inward. You get a chill layer (sorry I forget the correct term, need second cup of coffee)

Gt Obach · 22nd March 2005, 06:37 AM

hi all
this is an interesting post..
- alloy has lots to do with the coloring but so does the etch...
- even the quenched steel will show up darker..

for awhile the blades i've made... sometimes have a grey hue all the way to a bluish color.. but yet I alter my formula very little.... except for the occasional frankenwootz ..

personally, i wouldn't alter museum pieces with nital... but for my steel, it brings out an accurate picture ... example:
http://dark.unitz.ca/~gthomas/myweb/p1.JPG

the rest of the post is on primal bout half way down the post
http://p222.ezboard.com/fprimalfires...icID=156.topic

recently.... Jeff Pringle posted a wootz knife he made..... and used an iron sulphate etch..... he said he had to add sulphuric acid to it and it worked well... but it was different than my fav (nital)
here... take a peek
http://www.knifenetwork.com/forum/sh...ad.php?t=27383

hope that helps a little
Greg

Ann Feuerbach · 23rd March 2005, 03:37 PM

Yes, nital and ferric chloride will give a different etch. Other factors which need to be considered are: if you want to darken the globular cementite or the matrix, which basically can be ferrite or pearlite. Sort of a negative or positive effect, dpending which one you want to darken. I have also heard the Worstershire sauce works well. And yes, any additional trace elements can also effect the pattern.
So I have been told.. when they re etch Japanese blades, they first do an elemental map of the blade to see what elements are where (phosphorus, etc). Then they choose the etchant to bring out the best pattern.

Gt Obach · 23rd March 2005, 04:32 PM

Worstershire sauce... .. that is something I haven't tried.. but I will surely give it a go
- i've tried Alum with abit of acid... but I could never get it to work right... it does make your hands a nice purple

I aggree with all my heart that the elemental make up does funny things to the etch... even two blades from the same ingot can take on subtle hue differences pending how they were forged and quenched

in most of my blades... the etched matrix is tempered martensite.... even the swords i've made were in this state too.. but this summer i'll have to experiment with pearlite
-
- in plain damascus... even vinnegar will work well... but I find it etches better if it used a couple times.... therefore its' more of acetic acid and an iron salt...
--- think those 2 components are the key.... the acid and the iron salt

thank you
Greg

17th March 2005, 04:48 AM	#3
Montino Bourbon Member Join Date: Dec 2004 Location: Santa Barbara, California Posts: 301	magnetically-influenced wootz Just a thought; what would happen if the ingot was allowed to cool in a strong magnetic field? Would the dendrites align with the field? Something for the experimenters to try!

16th March 2005, 06:43 PM	#1
Ann Feuerbach Member Join Date: Feb 2005 Posts: 133	Hi Lew, Yes the tannic acid solution does not make the pattern pop out as much, but from a conservation (museum) point of view, ferric chloride is not an acceptable method. Even with neutralization. With this process, we do not use water. I have also found a method to give a great golden sheen. I am still working on that one, but it is beautiful. 99% of curators would not let a conservator use ferric or nitric acid. On another note, I have done extensive research on the different between wootz and pulad. It seems that the difference in the pattern is initally due to the fact that the indians take out the ingot while liquid and the solidification and cooling is very fast, which produces small dendrites. In the persian pulad process, they ingots solidify and cool slowly, thus producing large dendrites. From Verhoeven et al reserach, the cementite aligns along the impurities from the dendrite formation, thus big dendrites, coarser pattern vs faster cooling, smaller dendrites, finer pattern. However, final forging and trace and minor elements also plays a part. Ann

16th March 2005, 06:45 PM	#2
Ann Feuerbach Member Join Date: Feb 2005 Posts: 133	Oh, I forgot, also the Persians added Mn to the mixture, which probably accounts for the darker phase contrast.

17th March 2005, 02:49 PM	#4
Ann Feuerbach Member Join Date: Feb 2005 Posts: 133	Interesting question. However I do not think so, if you look at castings, the dendrites grow from the outside inward. You get a chill layer (sorry I forget the correct term, need second cup of coffee)

22nd March 2005, 06:37 AM	#5
Gt Obach Member Join Date: Mar 2005 Posts: 116	hi all this is an interesting post.. - alloy has lots to do with the coloring but so does the etch... - even the quenched steel will show up darker.. for awhile the blades i've made... sometimes have a grey hue all the way to a bluish color.. but yet I alter my formula very little.... except for the occasional frankenwootz .. personally, i wouldn't alter museum pieces with nital... but for my steel, it brings out an accurate picture ... example: http://dark.unitz.ca/~gthomas/myweb/p1.JPG the rest of the post is on primal bout half way down the post http://p222.ezboard.com/fprimalfires...icID=156.topic recently.... Jeff Pringle posted a wootz knife he made..... and used an iron sulphate etch..... he said he had to add sulphuric acid to it and it worked well... but it was different than my fav (nital) here... take a peek http://www.knifenetwork.com/forum/sh...ad.php?t=27383 hope that helps a little Greg

23rd March 2005, 03:37 PM	#6
Ann Feuerbach Member Join Date: Feb 2005 Posts: 133	Yes, nital and ferric chloride will give a different etch. Other factors which need to be considered are: if you want to darken the globular cementite or the matrix, which basically can be ferrite or pearlite. Sort of a negative or positive effect, dpending which one you want to darken. I have also heard the Worstershire sauce works well. And yes, any additional trace elements can also effect the pattern. So I have been told.. when they re etch Japanese blades, they first do an elemental map of the blade to see what elements are where (phosphorus, etc). Then they choose the etchant to bring out the best pattern.

23rd March 2005, 04:32 PM	#7
Gt Obach Member Join Date: Mar 2005 Posts: 116	Worstershire sauce... .. that is something I haven't tried.. but I will surely give it a go - i've tried Alum with abit of acid... but I could never get it to work right... it does make your hands a nice purple I aggree with all my heart that the elemental make up does funny things to the etch... even two blades from the same ingot can take on subtle hue differences pending how they were forged and quenched in most of my blades... the etched matrix is tempered martensite.... even the swords i've made were in this state too.. but this summer i'll have to experiment with pearlite - - in plain damascus... even vinnegar will work well... but I find it etches better if it used a couple times.... therefore its' more of acetic acid and an iron salt... --- think those 2 components are the key.... the acid and the iron salt thank you Greg