Corrosion on gilded keris blade

krissman · 15th January 2015, 10:38 PM

Several of my keris blades display gilded naga motifs. One of them is showing copper sulfate corrosion between the gilding and the iron. I have been able to remove the corrosion from one side fairly easily with toluene on cotton swabs but thought before doing the other I would ask if there might be some better or safer method. Also, I would appreciate learning how future corrosion might be prevented. Finally, I am wondering if the "gilding" on this blade might in fact be brass, not gold. Two images are attached. One shows the hilt and the other shows a section of the blade where corrosion can be seen. If anyone has any thoughts, I would be grateful to have them.

This is my first post with photos. I cannot tell if they will come through. If they don't I will try again. Thanks for bearing with me.

David · 16th January 2015, 12:30 AM

Welcome to the forum Krissman.
Alas i must say that the reason for what you call copper sulfate corrosion is in all likelihood because the gilding is not gold. This is a fairly low level keris of the type generally sold in markets and shops as souvenirs. They generally do not employ real kinatah (gold decoration). This could be brass or copper. So considering that i don't think you need to worry too much for the safety of the blade or the "gilding".
Once cleaned you may be able to prevent re-occurance of the corrosion by keeping the blades well oiled.

Battara · 17th January 2015, 02:16 AM

The hue of the yellow metal to me looks like brass. David is right, I have seen this on keris made for the market.

Of course this is why you are seeing green patina - the copper oxidation due to the copper that is a component of brass.

krissman · 24th January 2015, 09:45 PM

Thank you for the input. I suspected the piece was not old or "authentic" but paid for it accordingly. Since posting, I have gone ahead and successfully used the toluene to remove the corrosion and coated the blade with Ballistol which is used by gun enthusiasts for protecting steel and brass. We'll see how well that works out long term.

I do have to ask this though. When a blade has real gold on it, how is it applied? When electroplating gold, it is common to first plate the piece with copper and then plate it with gold. How was gold applied traditionally in Indonesia and how is it applied today? Was it fire gilded using mercury?

Thanks.

David · 25th January 2015, 02:57 AM

I believe that there are a few methods for gold attachment to a keris (kinatah). I am afraid i am not the best person to accurately describe the processes. Alan???

A. G. Maisey · 25th January 2015, 06:05 AM

Yes, fire gilding was used, and maybe still is used. There was an old bloke in Solo who was doing it up until a few years ago I don't know if he still is.

Kinatah work has several levels of quality, and I doubt that I know them all.

Probably the very best is the method where the steel is carved to approximate shape, then fairly heavy gold is applied over the carving in a similar fashion to koftgari work, and that gold is then carved with the motif.

Then there is the work that is essentially koftgari, and uses gold of about the same weight as other koftgari.

Then we have the cheapy stuff where thin gold sheet is glued over the steel. I've seen really old work done like this and using a heavy sort of natural resin, but these days they use a modern glue, I don't know exactly what, but my guess would be Alteco, a super-glue.

Oh yes, there's another way of doing it where a hole with undercut sides is cut in the steel, then a gold plug is hammered into the hole, leaving a mass of gold on the blade surface, this external gold is then carved with the motif.

I have seen parts of all these processes, but I do not know any of them in detail.

David · 25th January 2015, 07:19 AM

Thanks Alan, that's at least an overview.

krissman · 15th February 2015, 12:55 AM

Thanks for all the good information. Fire gilding is what I imagined was used the most and hadn't thought about the koftgari and "plug" methods. They all make sense.

Will M · 15th February 2015, 04:05 PM

Renaissance Wax is a micro crystaline wax that is great for protecting blades.
I apply it wth a soft cloth then a heat gun to help it bond. Always better to handle a dry blade than an oily one that attracts dust etc.

15th January 2015, 10:38 PM	#1
krissman Member Join Date: Jan 2012 Posts: 4	Corrosion on gilded keris blade Several of my keris blades display gilded naga motifs. One of them is showing copper sulfate corrosion between the gilding and the iron. I have been able to remove the corrosion from one side fairly easily with toluene on cotton swabs but thought before doing the other I would ask if there might be some better or safer method. Also, I would appreciate learning how future corrosion might be prevented. Finally, I am wondering if the "gilding" on this blade might in fact be brass, not gold. Two images are attached. One shows the hilt and the other shows a section of the blade where corrosion can be seen. If anyone has any thoughts, I would be grateful to have them. This is my first post with photos. I cannot tell if they will come through. If they don't I will try again. Thanks for bearing with me. Attached Images

16th January 2015, 12:30 AM	#2
David Keris forum moderator Join Date: Aug 2006 Location: Nova Scotia Posts: 7,024	Welcome to the forum Krissman. Alas i must say that the reason for what you call copper sulfate corrosion is in all likelihood because the gilding is not gold. This is a fairly low level keris of the type generally sold in markets and shops as souvenirs. They generally do not employ real kinatah (gold decoration). This could be brass or copper. So considering that i don't think you need to worry too much for the safety of the blade or the "gilding". Once cleaned you may be able to prevent re-occurance of the corrosion by keeping the blades well oiled.

17th January 2015, 02:16 AM	#3
Battara EAAF Staff Join Date: Dec 2004 Location: Louisville, KY Posts: 7,139	The hue of the yellow metal to me looks like brass. David is right, I have seen this on keris made for the market. Of course this is why you are seeing green patina - the copper oxidation due to the copper that is a component of brass.

24th January 2015, 09:45 PM	#4
krissman Member Join Date: Jan 2012 Posts: 4	Thank you for the input. I suspected the piece was not old or "authentic" but paid for it accordingly. Since posting, I have gone ahead and successfully used the toluene to remove the corrosion and coated the blade with Ballistol which is used by gun enthusiasts for protecting steel and brass. We'll see how well that works out long term. I do have to ask this though. When a blade has real gold on it, how is it applied? When electroplating gold, it is common to first plate the piece with copper and then plate it with gold. How was gold applied traditionally in Indonesia and how is it applied today? Was it fire gilded using mercury? Thanks.

25th January 2015, 02:57 AM	#5
David Keris forum moderator Join Date: Aug 2006 Location: Nova Scotia Posts: 7,024	I believe that there are a few methods for gold attachment to a keris (kinatah). I am afraid i am not the best person to accurately describe the processes. Alan???

25th January 2015, 06:05 AM	#6
A. G. Maisey Member Join Date: May 2006 Posts: 6,697	Yes, fire gilding was used, and maybe still is used. There was an old bloke in Solo who was doing it up until a few years ago I don't know if he still is. Kinatah work has several levels of quality, and I doubt that I know them all. Probably the very best is the method where the steel is carved to approximate shape, then fairly heavy gold is applied over the carving in a similar fashion to koftgari work, and that gold is then carved with the motif. Then there is the work that is essentially koftgari, and uses gold of about the same weight as other koftgari. Then we have the cheapy stuff where thin gold sheet is glued over the steel. I've seen really old work done like this and using a heavy sort of natural resin, but these days they use a modern glue, I don't know exactly what, but my guess would be Alteco, a super-glue. Oh yes, there's another way of doing it where a hole with undercut sides is cut in the steel, then a gold plug is hammered into the hole, leaving a mass of gold on the blade surface, this external gold is then carved with the motif. I have seen parts of all these processes, but I do not know any of them in detail.

25th January 2015, 07:19 AM	#7
David Keris forum moderator Join Date: Aug 2006 Location: Nova Scotia Posts: 7,024	Thanks Alan, that's at least an overview.

15th February 2015, 12:55 AM	#8
krissman Member Join Date: Jan 2012 Posts: 4	Thanks for all the good information. Fire gilding is what I imagined was used the most and hadn't thought about the koftgari and "plug" methods. They all make sense.

15th February 2015, 04:05 PM	#9
Will M Member Join Date: Mar 2012 Location: In the wee woods north of Napanee Ontario Posts: 390	Renaissance Wax is a micro crystaline wax that is great for protecting blades. I apply it wth a soft cloth then a heat gun to help it bond. Always better to handle a dry blade than an oily one that attracts dust etc.