Pickles are one of the harshest chemicals jewellers use in the studio and even the branded ‘safety pickle’ is harmful to both people and the environment. Alternatives such as citric acid and salt and vinegar solutions work just the same and are safer to handle and to dispose of.
Citric Acid Pickle
By Ute Decker
Components: Citric acid powder and water. You can buy a 500-gram bags of citric acid powder online. Your local pharmacy may also be able to order it overnight, small grocers and supermarkets may also stock this in their canning sections. Citric acid pickles take slightly longer than traditional pickles but work just as well and unlike traditional pickles, they are biodegradable and gentler on the body and your clothes.
Preparation: Mix 1 part citric acid powder with 5 – 7 parts of water, depending on the strength required. Always add the citric acid to the water, not the water to the acid. Some say that distilled water works better than tap and prevents the growth of micro-organisms but tap is also suitable. As water evaporates from the solution, simply add more water. If the pickle is weak, add more acid. If used warm in a crock pot, ventilation is recommended.
Application: Should be used warm for best results in removing flux, oxides and firescale on silver, gold, brass and copper after soldering.
Safety note * Do not overheat or put a hot piece of metal into any pickle to ‘quench’ it. The steam that rises as a result is acidic and may irritate the lining of your lungs. This health hazard is considerably greater when using a toxic pickle variety. Copper (as well as gold, silver and platinum) is a heavy metal. Pernicious effects may result from long-term exposure through inhalation of dust, fumes or vapours. Therefore, pickle should only ever be used warm and never overheated to produce excessive evaporation that you could inhale.
Safe Disposal: A citric acid pickle solution will work effectively for many months however when it needs to be disposed of you should do this with precaution. See below for the same disposal of pickles.
Citric acid by itself is not classified as a hazardous material but after it has been used as a pickling solution, it contains copper. Copper compounds are very toxic for aquatic life if poured down the drain and they kill off the bacteria needed for the functioning of waste water treatment, so they need to be disposed of properly. See pg. 26 of this toxin classification report for the hazards of copper.
Neutralizing the pickle will not remove the copper so even neutralized pickles are hazardous. All oxidizers, including liver of sulfur and other proprietary oxidizing solutions, are also hazardous materials.
Collect hazardous materials in clearly labelled plastic containers with tight lids for storage in the studio and during transportation to an appropriate disposal facility, preferably with their original labels. Some councils in the UK will still pick up hazardous waste. To find out more about hazardous waste collections in your area see here.
Salt & Vinegar Pickle
By Ute Decker
This option is simple, cheap and accessible.
Components: White wine vinegar plus iodised or kosher salt is recommended by many. Ordinary table salt works effectively, too.
Preparation: About one cup of vinegar to one teaspoon of salt or slightly more, if required.
Application: Should be used warm for best results. It works quicker than citric acid and good results have been reported for both silver and gold. It does tend to evaporate, with beautiful salt crystals forming around the edge of the pot. You can just top up the solution with vinegar and salt. Leave the lid askew when you cool the solution, or the salt crystals may seal it on.
Practice note * Vinegar is also used effectively to wash away investment when cleaning off castings. (Keep this separate from pickling solution so not to introduce unnecessary dirt into your pickle).
Disposal: Same applies as to the disposal of citric acid. See below.
Safe re-use and disposal of pickles
Written by Jennifer Wall, the Metals Studio Manager and an instructor at the Oregon College of Art and Craft, for the Ethical Metalsmiths group, this method uses steel wool to extract copper out of a spent pickle bath so that it may be reused and disposed of safely i.e. not by pouring it down the drain. The article with an explanation of the method as well as some other helpful green studio tips can be found here.
Resins like epoxies and polyesters contain harmful petrochemicals (chemical products made from fossil fuels such as petroleum, coal and natural gas) which can cause hormone imbalances with extended exposure and are harmful for both the atmosphere and water systems.
Eco-resins make up a broad group of polymer resins that are non-toxic, renewable or solvent-free (water-based). Bio-resins are based on plant and vegetable extracts.
Directions for using Bio-Resins
Jesmonite, although not as eco-friendly as other eco-resins, is better than traditional resins as it is non-toxic and water-based.
Directions for using Jesmonite can be found on the following sites:
To avoid the harmful risk of lead poisoning through inhalation, look for lead free enamels such as Cookson’s lead free enamel.
For degreasing metals, a simple biodegradable oil based soap works fine.
Dr. Bronners Castile Soaps for example which can be found at most health food stores. Use 6 tbs. in a 6-quart/6-litre slow cooker
Eggs for Oxidising
There are many articles and blog posts of jewellers that use eggs for oxidising metals as an alternative to liver of sulphur. See the following links for directions on this method.
From the Jewelry Making Journal – How to oxidize sterling silver and copper with boiled eggs
From the Beading Gem – Tips for how to use boiled eggs for metal patination
Note * Using boiled eggs for oxidising metal still produces hydrogen sulphide. It is a small amount, but you could produce the same amount if you used a small amount of liver sulphur to start with as well. Although using boiled eggs is a relatively safe option, you are still using resources and energy to do this i.e. boiling water and consumption of eggs.
Electrolyte etching is a process of metal etching that is less hazardous than traditional methods of metal etching that use caustic acids. The process of electrolytic etching uses an electric current rather than acids or caustic chemicals and although it still requires the use of copper sulphate, this is less of a hazard so is easier to safely manage than the chemicals used in other methods. Additionally, the steel wool method for extracting copper sulphate out of a spent copper bath, can be used here just the same as with reusing a spent pickle (see non-toxic jewellers pickle). The paper below written by Dauvit Alexander outlines the process of electrolytic etching.
Cadmium-Free Solders & Fluoride-Free Fluxes
Cadmium and Fluoride are chemicals commonly used in the soldering process. The negative impacts of prolonged exposure to these elements is well documented. Breathing in the fumes produced when working with solders that contain cadmium, a known carcinogen, has toxic effects on the body including liver and kidney damage. Additionally, fluoride fluxes which are commonly used with solders have negative impacts on the respiratory system if the fluoride fumes are inhaled in the soldering process. The results of the continued exposure to these toxins are avoidable by using solders free of cadmium and fluoride free fluxes.
- Saru Silver
- GS Metal Joining
- Hoover and Strong
For a truly tested non-toxic fluoride and chlorine free flux, Firescoff has come recommended.
Silica-Free Polishing Compounds
Cookson’s Luxi Bars – set of nine, each with specific metal use
Cleaning Your Silver
By Ute Decker
If you occasionally wash your pieces in warm water with a phosphate-free detergent, carefully rinse and then thoroughly dry them with a soft cotton cloth, that may be all that is needed.
Organic Silver Polish (Aluminium Foil and Soda)
For stronger tarnishes, the use of this non-toxic, simple and efficient method is advised. No rubbing or scrubbing is involved.
- 1 tsp baking soda
- 1 tsp salt
- boiling water
- glass or ceramic container
- aluminium foil
The silver object is placed in a large glass or ceramic container lined with aluminium foil. For the electro-chemical reaction to occur the silver must touch the aluminium. The baking soda and salt is sprinkled over the object. Boiling water is then poured until the entire piece is covered. You may immerse several pieces at once taking care they do not rub and scratch each other. Depending on the amount of water, additional baking soda and salt may be required.
Results should be visible within minutes.
Not advisable for any jewellery that has been intentionally blackened as this will remove all the blackness. Equally not suitable with heat-sensitive or porous stones. Finish by washing the silver objects in warm water with phosphate-free detergent, rinse well, then dry thoroughly with a soft cloth and if necessary a hair dryer.
As with all cleaning products the pieces should not be left in contact with the solution longer than necessary to remove the tarnishing and when using gloves, use latex and avoid rubber gloves.
Greg Valerio and Cally Oldershaw, The Red & Green Book
This is an introductory manual for jewellers looking to take the early steps towards a more ethical practice. The individual modules of this book can be downloaded from Fair Jewelry Action website.
Society of American Silversmiths, Safer Alternatives
Society of American Silversmiths, A Metals Workshop Safety Report: Safety and Substitutes
The Incorporation of Goldsmiths disclaim any liability for damages or injuries as a result of any use, or application of products listed here or elsewhere on the site. Users must always handle chemical products with care: before using any product, always read the Manufacturer’s Safety Data Sheet (MSDS), use proper ventilation and safety handling tools according to the products chemical properties, and dispose of waste appropriately and safely referring to your local region’s waste disposal procedures, health and safety requirements and bylaws.