Ask Betsy: August Edition

ask betsy

Q:  What is the best way to use Liver of Sulfur for patinas?


A: Liver of Sulfur (LOS) is one of many solutions used to create a patina on metal. It is a mixture of potassium sulfides and comes in a number of forms. Nuggets are a dried form that needs to be dissolved in water and decomposes when exposed to light and air. Gel and liquid forms are stabilized so they don’t have the same decomposition factor, but are also diluted in water for use.

PLEASE NOTE: There are some toxicity issues with LOS, so please read labels and warnings. Most people don’t have any problems, but it is a good idea when using chemicals to read either the label or the MSDS. It is also best to wear gloves and work in a well-ventilated area.

LOS works best on metals with a copper content. Sterling silver and copper get the best results. Fine silver and Argentium may need longer to take a patina as the copper content is lower than sterling. Brass can take on a grayish sheen but probably not too much color.

Many people tend to use too much and make it too strong. Once combined with water it does not last, so only mix as much as you need for what you are currently doing. Make sure your metal is free of grease and dirt, and make sure any pickle that might have gotten into hollow areas has been removed.

If you want to get colors, it is best to use a weak solution and go slowly. Sometimes it helps to use warm water, and you can try adding a drop of household ammonia. Dip your piece until you see some color, rinse under water, and dip again until you get the colors you want. Be advised that these colors are generally not very stable over time since they continue to react with sulfur in the environment and can get duller and darker. You can seal the piece to promote longevity, but be aware that any sealant that is applied will probably dull the bright colors. The best sealants to use would be sprays as you are not rubbing the surface, but there will still be some dulling.

If you are looking for grays and blacks, it is still best to dip multiple times. The metal will get dark if you leave it in the solution, but trying to get to black too quickly will result in a patina that can flake off. The best method is to dip, rinse, brass brush with soapy water and dip again until you reach the depth of color you want. This will give you a smooth, even finish. 

Stay safe and well, and be sure to send your questions to askmassc@gmail.com!