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#1 |
Member
Join Date: Jan 2005
Posts: 485
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hi,
i think jens' contribution has been a little overlooked. to find a direct location for indian decoration is almost impossible, as most that lend towards indian arms will agree. hendley spent many years of his life in india, whilst assuming relatively high, important roles in indian society, studying indian decoration. his interest was not so much in antique style, but more in the 'modern' day practice of an old legacy. in his volumous works, he left a fingerprint of decorative style which we can associate with almost definate certainty. in his studies, he worked alongside the decorators of the age and recorded them well. this decoration, as jens has found, seems to stem from the khota region. there are not many pieces in private collections, nor in internationally acclaimed museums that can claim such certainty. well spotted and stated!! this style of decoration ought to be noted as we has now seen a definate example, wheres as before we had but a good illustraion. there may be in existence variations of this style which we can assume hail from the same region, but i would be surprised if anyone can now doubt the origin of this piece. |
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#2 |
Member
Join Date: Feb 2005
Posts: 133
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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 |
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#3 |
Member
Join Date: Feb 2005
Posts: 133
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Oh, I forgot, also the Persians added Mn to the mixture, which probably accounts for the darker phase contrast.
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#4 |
Member
Join Date: Dec 2004
Location: Santa Barbara, California
Posts: 301
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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! |
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#5 |
Member
Join Date: Feb 2005
Posts: 133
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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)
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#6 |
Member
Join Date: Mar 2005
Posts: 116
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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 |
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#7 |
Member
Join Date: Feb 2005
Posts: 133
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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. |
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