Hello Everyone, I recently discovered the joys of Burmese Opium Weights via a recent trip to Burma, Thailand and Laos.
In attempting to educate myself on the topic I came across the wonderful resource that is this Forum.

I purchased the 2 x 20 Tical 'Mon Ducks' in Rangoon and the others in Bangkok and Vientiane.
A question for members concerning my 'Mon Duck A' A1 & A2. The weight is heavily soiled and I was wondering if it is possible to clean the weight without destroying the patina?

What methods should I attempt, and are there any cleaning fluids/solutions members would recommend.














Regards
Arche

I’m not going to claim archival restoration expertise, but I have made a number of various mistakes that I can help you avoid.

No caustic fluids of any type. No gas, etc. (I let a house boy in Yangon clean a couple and discovered that he dipped them in battery acid. Needless to say, no more patina on those!)

Brasso and other metal polishes work, but I think it generally unnecessary. I find a brush and buff cloth generally best. Given heavy encrustation, I go to fine-grade brass brushes. These can leave a hint of brass color, but that buffs off easily. Otherwise, the stiffest shoeshine brush (clean/no polish residue) is pretty good.

I find that the true patina is inherent to the metal. Unless a caustic agent damages the metal, pretty much anything else you do is getting you down (through the dirt) to the true patina.

I have been repeatedly surprised to discover a very different metal under the layers of crud and dirt. You basically release the true patina to the light.

The results can vary widely. At times, I hoped I’d find a lovely metal, and found nothing special. More often, I found treasure. Many of them “shine up” very nicely, only to oxidize or tarnish quickly. Within a month, the dark (old-looking) patina was back but now clean. This is perfect. Taking time to occasionally handle them and rub them with a soft cloth also helps.

The only few I was sorry to have brushed up were those that were low quality material to begin with. These are the ones that are made to look better by the dirt and crud. ?

Anyway, I’ve wasted many a pleasant hour brushing and rubbing away with a soft cloth.

Enjoy.

One more quick comment. I wouldn’t clean that beast very much. I’d guess the metal would be little improved. Brush and soft cloth only.

Those ducks look like they could be very nice under there.

My method (among many methods) for bronze is

First: I use an apparatus of supersonic waves. Between 1 and 5 minutes. Try! I take care that the pores do not open.

Second: I carry out a thorough cleaning by a hard toothbrush using a cleaning powder (in Germany Ata or Vim ) to take away the surficial dirt. A genuine patina will not be affected. A soft brass brush may help as well.

Third: If more rests of dirt are left I remove them carefully with a steel needle of the dentist (in general strictly forbidden!) without injuring the patina. Sometimes the dirt is so hard or tough that this is the only chance to get rid of it.

Forth: To preserve the weight I put weapon oil (Balistol) on it and wait for some days until it is completely dry. Normally that is sufficient for a final protection.

Fifth: If the weight is strongly corroded, it is to recommend to put an "Antique Wax" for metal on it. It can be produced by mixing bee wax, paraffin and carnauba wax in equal parts plus turpentine . Others dip the weight into cooking (acid free!) paraffin (be careful, very hot!). After cooling surplus paraffin must be mechanically removed.

Good luck! hartmutmollat

I have a somewhat related question: How can I get rid of the lead (or other soft metal) plugs found on some of my weights? I understand these were added in later times to bring the weights up to newer mass standards, but to restore the original forms I'd like to melt off these additions. Scraping them off seems like a bad option--as it would take forever, might not be as thorough, and would risk damaging the patina.

Hallo puffin,

lead has been applicated to the animal weights
1. to restore the mass which had decreased by wear and tear or
2.(rarely) to adapt the mass of a weight to another standard i.e. in Burma from 15 g/Tk to 16,3 g/Tk.

The lead is part of the history of the weight. Therefore, I would never take it off even if the application is not nice. Since lead has a melting point of only 327 degrees C it must not be very difficult to remove it from the weight using a gas-burner. As I have no experience with that, I cannot tell you, what you will find behind the lead. Anyway, keep in mind that you will extinguish the life of the weight!

Best regards hartmutmollat

Thanks for the advice. I agree about the value to be had in verifying the accuracy of the weight--and for that reason I'm not going to mess with any particularly old weights with plug additions. But for other more standard and recognizably genuine weights, where validation is not an issue, I see removing the lead as different only in degree from the general cleaning every collector performs. After all, encrusted dirt and grime are part of a weight's life and history too, but arguments are not generally made for preserving them.