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Originally Posted by BluErf
I'm not a conservator, but I extremely horrified by what you have done! 
Though 120 degrees will do no damage to the blade, spare a thought for the hilt, for it is also an integral part of a complete keris. A good old hilt is a record of the carving skills and aesthetics of a period past. Destroying it is like burning books. |
Hello BluErf,
I am not a conservator nor a conservative person myself but I take the full responsibility of what I have done and I will try to explain why:
Let me first say that the 2 hilts in question (pictures 6.1 and 6.3 in my hilt book) are
extremely precious to me and that I did not make this experiment before a careful risk analysis. Hilt # 6.1 is made from hippo ivory and 6.3 from dugong ivory I think and both of them have a particularly dense and homogenous structure with virtually no cracks.
Ivory is considered as an organic material but actually it is mostly inorganic, containing about 55% of calcium and some magnesium phosphate, the rest bein collagen material. This is obviously a very positive factor regarding the heat resistance of the material (I looked for some info on Internet about the heat resistance of ivory but did not find anything).
I took full advantage of the failed steaming experience performed by Pak Ganja to draw 2 conclusions:
1. Ivory is not affected by exposure to a temperature of 100 °C in fully humid conditions (humidity is considered as very harmful for ivory).
2. A temperature of 100 °C (or may be a little less) is not sufficient to soften the gluing resin around the peksi hole.
My conclusion is that for softening the resin, you need to heat the peksi and peksi hole
(i.e the inside of the hilt) to a temperature above 100°C.
As my previous experiences with a candle failed due to insufficient heat flux or lack of patience and I have no kerosene lamp or equivalent, I decided to heat the whole blade into the oven set on hot air circulation and heated progressively for avoiding temperature peaks and thermal stresses on the hilt.
As compared to the traditional heating method with a flame, the main difference is that the hilt is also subject to the same temperature as the blade, i.e. 120°c maximum, but as I said and from my grinded teeth experience at the dentist, I felt confident that the ivory hilt could safely withstand it without damage. A positive factor of the oven procedure in my opinion is that there is no thermal gradient across the hilt as with a flame (120°C at the peksi hole or inside of the hilt and ambient on the outside as ivory is a highly insulating material).
To date I guarantee you that there not the slightest sign of damage or decay to the hilts, but if anyting wrong appears in future I will advise the forum accordingly and apologize for my mistake (no progress is made without daring break the tradition).
Still extremely horrified?
Best regards
Jean