Antique Moro Gunong

Ian · 20th February 2018, 09:47 PM

Thanks Kai.

Yes, it's arsenates [–AsO4(-3), etc.] not oxides of arsenic [As2O3, As2O5, etc.] that are black.

I'm not sure that silver oxidation explains the intense black oxidation that I observed on my samrit covered daab. Some time ago I was sent an old formula for samrit, and no mention was made of silver in the mixture if I recall correctly. Also, the intensity of the black color was much more than I see on silver covered pieces from the same general region--silver oxidation tends to be more grey than black.

I have another Lao daab from the 17th C with a samrit hilt that has virtually no oxidation, and I have no explanation why one would have such a dark patina and the other virtually none. Presumably it reflects different components in each sample of samrit.

Battara · 21st February 2018, 01:48 AM

Actually for silver the longer the oxidation the blacker it gets.

Another consideration is the copper content, because when copper is involved, then the darker the oxidation gets as well. Copper often gets the green/blue/even multi-color patinas. However, when mixed with certain metals, the patina might change depending on the metal mix. Copper/tin mixes (bronzes) may yield a green patina, but can also give a dark brown to even black patina. This black patina can also be seen on silver/copper mixes where the mix has a large percentage of copper (in fact, silver/copper mixes with large amounts of copper often patina quicker than either silver or copper by themselves!

).

Hope this is now clear as mud...........

Ian · 23rd February 2018, 12:55 AM

Thanks Jose.

F. de Luzon · 23rd March 2018, 03:50 PM

Thank you all for your comments! I haven't found time to have the metal tested but I'll give an update as soon as I have information.

Kind regards,

Fernando

ACP · 27th March 2018, 05:17 PM

Would it be possible for you to give me a summary of how you restored the gunong? I have one that barely escaped the bombing in Marawi and is just sitting inside my desk drawer. Big thanks in advance

F. de Luzon · 29th March 2018, 04:18 PM

Hi ACP, What's the condition of your gunong? Can you please post a picture? Thanks.

Fernando

ACP · 31st March 2018, 08:06 PM

Thanks for the reply, i will try to post some pics when i get back home.

ACP · 2nd April 2018, 05:09 PM

Ill try to post the picture when I get back sir. Im currently out of town. My apologies

20th February 2018, 09:47 PM	#1
Ian Vikingsword Staff Join Date: Dec 2004 Location: The Aussie Bush Posts: 4,579	Thanks Kai. Yes, it's arsenates [–AsO4(-3), etc.] not oxides of arsenic [As2O3, As2O5, etc.] that are black. I'm not sure that silver oxidation explains the intense black oxidation that I observed on my samrit covered daab. Some time ago I was sent an old formula for samrit, and no mention was made of silver in the mixture if I recall correctly. Also, the intensity of the black color was much more than I see on silver covered pieces from the same general region--silver oxidation tends to be more grey than black. I have another Lao daab from the 17th C with a samrit hilt that has virtually no oxidation, and I have no explanation why one would have such a dark patina and the other virtually none. Presumably it reflects different components in each sample of samrit.

21st February 2018, 01:48 AM	#2
Battara EAAF Staff Join Date: Dec 2004 Location: Louisville, KY Posts: 7,352	Actually for silver the longer the oxidation the blacker it gets. Another consideration is the copper content, because when copper is involved, then the darker the oxidation gets as well. Copper often gets the green/blue/even multi-color patinas. However, when mixed with certain metals, the patina might change depending on the metal mix. Copper/tin mixes (bronzes) may yield a green patina, but can also give a dark brown to even black patina. This black patina can also be seen on silver/copper mixes where the mix has a large percentage of copper (in fact, silver/copper mixes with large amounts of copper often patina quicker than either silver or copper by themselves! ). Hope this is now clear as mud...........

23rd February 2018, 12:55 AM	#3
Ian Vikingsword Staff Join Date: Dec 2004 Location: The Aussie Bush Posts: 4,579	Thanks Jose.

23rd March 2018, 03:50 PM	#4
F. de Luzon Member Join Date: Dec 2016 Posts: 184	Thank you all for your comments! I haven't found time to have the metal tested but I'll give an update as soon as I have information. Kind regards, Fernando

27th March 2018, 05:17 PM	#5
ACP Member Join Date: Mar 2018 Location: Western Visayas Philippines Posts: 16	Would it be possible for you to give me a summary of how you restored the gunong? I have one that barely escaped the bombing in Marawi and is just sitting inside my desk drawer. Big thanks in advance

29th March 2018, 04:18 PM	#6
F. de Luzon Member Join Date: Dec 2016 Posts: 184	Hi ACP, What's the condition of your gunong? Can you please post a picture? Thanks. Fernando

31st March 2018, 08:06 PM	#7
ACP Member Join Date: Mar 2018 Location: Western Visayas Philippines Posts: 16	Thanks for the reply, i will try to post some pics when i get back home.

2nd April 2018, 05:09 PM	#8
ACP Member Join Date: Mar 2018 Location: Western Visayas Philippines Posts: 16	Ill try to post the picture when I get back sir. Im currently out of town. My apologies