Monday, April 20, 2015

Never Clean Sterling Silver with Ammonia


Someone asked me about a pendant she was having problems with, it tarnished in a fairly short time. She had sealed it with ProtectaClear, but the sterling tarnished anyway.

She told me about how she finished the metal. She had a very in-depth, complicated process she used on the sintered sterling metal clay. She cleaned it with water mixed with Dawn and ammonia, dried it, and then cleaned it with denatured alcohol and dried again on a coffee mug warmer. She then coated it once with ProtectaClear and accelerated drying with a low temp warmer.

There is no need to complete all of these processes. Jewelry manufacturers warn their customers not to use ammonia on sterling because it's not good for sterling. It causes sterling to turn black and other problems develop, then it will not clean by conventional methods. Scrubbing with Dawn, a detergent, leaves the detergent in the pores. My husband is a chemical engineer, he says detergents are stronger than soap and harder to remove from something porous. In theory, soaking the piece in denatured alcohol helps displace water, but it will not displace detergent or ammonia. The ammonia may have been the problem, especially if the pendant wasn't washed thoroughly.

I don't know if she dipped it in liver of sulfur before she did all of this. I have found that if a freshly sintered piece of metal clay is placed into liver of sulfur, the liver of sulfur is absorbed inside the porous areas of the piece. Over time it tends to oxidize faster, from the inside out. I suggest burnishing the pores closed using a steel or brass brush before applying liver of sulfur. After oxidizing, place the piece into a mixture of baking soda and water to neutralize the liver of sulfur. This keeps it from continuing the oxidation process. Then soak it in water, removing any other chemicals left behind. Dry completely and then polish. I personally don't use a lacquer over sterling silver. Over time the sterling silver still oxidizes, at which point, the lacquer must be removed in order to polish it. 

Until next time, have fun claying around!





 
by Janet Alexander 
Technical Adviser

10 comments:

Roxanne Coffelt said...

Thank you for this! I saw someone clean a chain once with ammonia and a Q-tip. I haven't tried it, but it looked like such an easy way to clean a chain. I won't do it now.

Janet Alexander said...

Hi Roxanne, there is a much easier way to clean chains with non-toxic chemicals including vinegar, baking soda, and aluminum foil. Check out my blog on this. http://pmccblog.blogspot.com/2014/06/a-quick-and-easy-way-for-removing.html

Anonymous said...

In regards to your comment about applying liver of sulfur after tumbling, I've often wondered if there is much of a difference in using liver of sulfur vs. Black Max to patina the silver. I haven't been able to find any articles on this topic. I wonder if one is better than the other in keeping the recesses dark but the polished silver bright over time. Does anyone have any experience with the comparison of each of these patinas?

Seavbeach Designs said...

Janet, I have some questions regarding this post. I had always hand polished my pieces until the last few years while taking my certification classes we had put our pieces in the tumbler with a drop of dish soap. In the last few years those pieces have tarnished but the ones before I got a tumbler remain shiny silvery and pretty. I do feel that using an additive in the tumbler may be the cause. What are your thoughts on this? Can you still tumble without adding anything other than water?
Anise

Janet Alexander said...

Hi Anonymous!
Yes, I have used Black Max for many years. I prefer it over liver of sulfur when I want a pitch black affect on my metal or when I want it only in particular spots. Maybe I will write a blog on this!

Janet Alexander said...

Hi Seavbeach,
There shouldn't be any reaction from soap in the tumbler causing your pieces to tarnish. I have had a problem with the rubber degrading from the tumbler barrel causing the pieces to turn black. Soap is used as a lubricant allowing the steel shot to move across the metal more easily. Now, if that soap has any ammonia in it then this could cause tarnishing. I use Blue Dawn in my tumbler. There is a commercial product available for use instead of soap. Be careful using it. If you put too strong of a solution into the tumbler, it will degrade the barrel, like I mentioned before.

Anonymous said...

Janet,

I would like it very much if you wrote a blog about your use of Black Max!

Anonymous said...

Then it also would be true not to add ammonia to liver of sulfur to achieve more colors in the patina, correct? I read somewhere that adding ammonia can help bring out the patina colors.

Estate Sterling said...

Nice blog! This information is very useful for women who often use sterling silver products. To prevent scratches, each piece should be stored individually in its own case, pouch, or compartment. Be sure store sterling silver cutlery in a dry, cool place. In hot climates, it should be kept in an air-conditioned room.

ruralwannabe said...

In regard to the technique mixing vinegar and baking soda called out in the link posted,
http://pmccblog.blogspot.com/2014/06/a-quick-and-easy-way-for-removing.html,
vinegar and baking soda when mixed create a powerful acid, thus the fizzing. I use this combination to clean my bathtub drain. Is this really good for jewelry? Thanks.