Updated: 2/7/23, 2/4/23, 12/28/20, 8/4/18, 2/15/17
See the end of this post for links to additional information and videos on this topic.
What is pickle and pickling?
Oxidation on copper is made by heating with a torch.
Pickling is a process that removes oxidation and flux residues that develop during the soldering process. Pickles are (usually) a mixture of an acid or an acid salt and water that removes oxides and flux residues from metal. See my article: Soldering 101 – Oxidation, Flux, and Fire Scale Prevention for more information. Pickle does not remove fire scale or fire stain. The only way to remove the fire scale is with abrasives.
Because of the corrosive nature of acids and acid salts, the handling and use of pickle require specific safety precautions. Of course, the amount and degree of safety precautions vary depending on the type of pickle. There are certain pickles, like vinegar or citric acid pickle, that are much less dangerous than say, sodium bisulfate or sulfuric acid pickle.
See further down the page for more detailed information on acids.
After pickling your metal, you need to neutralize the acid – even if your pickle is made from vinegar or citric acid, with a base. If you don’t, the acid will continue to eat away at the metal. So, once you’ve removed your piece from the pickle, dunk it in a Pyrex or other type of ovenproof bowl containing a mixture of baking soda (a small handful) and (a few cups) of water. There is no exact recipe. You’ll know it is working if your piece bubbles when you place it in the neutralizing solution. Your neutralizer will also turn blue, after a few dunks. That’s just the copper in the metal coming off. If you are using just fine silver or 24-karat gold you won’t have turquoise pickle or rinse bowls as they don’t contain copper.
If you have hollow pieces to pickle, it is best to simmer or boil them in a neutralizing bath after pickling: hollow beads, hollow-formed rings, etc. Boiling the neutralizer allows the pickle to reach deep inside hollow spaces.
Don’t boil the neutralizer in a pot that you will cook in. Get a used one from the junk store and designate it for studio use only.
Before boiling in baking soda make sure that any stones or materials, used in the construction of your piece of jewelry, will survive at or above 212°F. If you have a sacrificial piece or a small chunk of your material, try that first. Items to be concerned about are emeralds (they often have fillers or oils in them), organics such as bone, pearls, shell or wood, opals, and many heat-treated stones.
How to Heat Pickle
Since most pickles work best when warm, you need something to keep them warm in. Most jewelers use a ceramic-lined crockpot or a commercially available pickle pot. Having a removable ceramic insert is best. You can remove the insert and change out your pickle without having to worry about damaging the electrical components. Use the lowest setting – unless you are using citric pickle which works better the hotter it is.
It’s important to only use a pickle pot with a ceramic liner as the acid will slowly eat away at any metal. Also, try to avoid pickle pots that have metal-trimmed lids or metal screws on the top to secure the handle. If your crockpot has metal on the top, you can paint it with an acrylic sealer to prolong its life. It is nearly impossible to find a crockpot without a metal rim on the lid!
Most crockpots are 3 quarts and small ones run around 1.5 quarts. You don’t need a 3-quart pot unless you’re pickling cuff blanks and other larger items. That said, I like having a large crockpot – just in case. I have a 1.5-quart pot for warming thermoplastics and for heating up my liver of sulfur.
A good source for pickle pots are resale shops like Goodwill. Check for cracks in the ceramic before you purchase them. They usually cost anywhere from $5.00 to $15.00 US – depending on your area and the size of the pot. And remember to avoid pots with metal edging on the lids – if possible.
In a pinch, you can use a coffee cup warmer and a pint-sized mason or canning jar as your pickling system. Extra benefit – You can also use the coffee cup warmer for drying metal clay pieces and enamels before firing and for heating liver of sulfur!
Notes on Pickling
- Always use Distilled Water to make your pickle. The minerals and metals in your water will react with the acid. Many people have a lot of iron in their water which can coat your brass, bronze, silver, etc. with the copper present in your pickle pot (remember the section on copper flashing, above?). Every time that you pickle a metal that contains copper, small particles of the copper are leached from the metal and deposited in the pickle. After several uses (sometimes only one or two times) you will notice that your pickle has turned blue/green. That color change signifies the presence of copper.
- A common misconception is that you need separate pickle pots for silver and for base metals (brass, copper, or bronze). This is simply not true. I’ve been using one pot, for a very long time, and have never had a problem with the copper in my pickle affecting my other metals. The copper ions will not harm your metal, slow your pickle or affect your silver and golds (either fine, sterling, or Argentium) in any way! Another reason to not have two pickle pots is more bench space!
- All pickles work best when warm. Don’t boil your pickle.
- When mixing up a new batch of pickle, remember to add the dry acid to the water. Don’t dump the water into the acid. Want to know why?
“A large amount of heat is released when strong acids are mixed with water. Adding more acid releases more heat. If you add water to acid, you form an extremely concentrated solution of acid initially. So much heat is released that the solution may boil very violently, splashing concentrated acid out of the container! If you add acid to water, the solution that forms is very dilute and the small amount of heat released is not enough to vaporize and spatter it. So Always Add Acid to water, and never the reverse.”
One of our biggest problems at Chimera Art Space’s Jewelry Studio is people leaving the pickle pot on. Someone will come in the next day and be met with a bunch of crystalized sodium bisulfate and copper particles. Not only is this a pain as it takes over an hour for it to rehydrate, or they have to make it new but it is also a fire hazard. The fix is this (I do this at home too): Hook your pickle pot up to a plug strip. Also, hook up a clip light or other type of small light to the strip. Turn the light on. Now, never turn it off again by its on/off switch! Instead, turn the plug stip off/on. If the light is on, so is your pickle!
- When mixing your pickle – no matter the type: Wear a good mask – I like 3M’s particulate mask, chemical-resistant gloves, and chemical safety goggles. Turn on your ventilation system. Even if wearing a particulate mask, keep your face away from the pickle pot. Wash hands well after mixing and using. Safety, safety, safety, please!
- Pickle strength can be adjusted. You can add more or (as in my case) less than the instructions state. I always use about 1/2 of what is recommended and it works fine. It all depends on how fast you want your pickle to work. I find the “pickling break”, maybe 5 minutes for the pickle to work, is a chance to work on either another project or another part of the project – there’s always something to be done! It’s time to hammer that wire or to get those jump rings closed.
- Neutralize, in your baking soda bath, any tools used to mix up your pickle like tongs, spoons, measuring cups, etc. – anything that came into contact with the acid! I’d put my gloves in the neutralizer too – if I was wearing them.
- Conversely, don’t forget to rinse the baking soda off of your spoons/tongs before putting them back in the acid. Over time, un-rinsed baking soda-coated-tongs repeatedly dunked in pickle, will neutralize it.
- Never again use the spoons, tongs, or measuring cups, that you used to mix up your pickle, for cooking! Label them “for studio use only”.
- Don’t forget to turn off your pickle pot when you leave the studio.
- If you “cook” your pickle, i.e. evaporate all the water, turn it off, and let the pot cool down. Ventilate your studio if necessary. When the pot reaches room temperature or even slightly warmer, you can slowly begin to add distilled water. Let the water and acid sit for 1/2 – 1 hour and then turn the pot on the low setting. Stir occasionally. You should be able to use the pickle again when the pickle heats up. It may take a few hours to totally re-absorb the acid. While you are waiting, go set up that power strip with your pickle pot and your clip light!
- Don’t put steel into the pickle pot unless it is stainless steel. Stainless is safe in pickle. Remove all binding wire before pickling – unless you are using copper or stainless steel wire. Regular steel binding wire, cross-locks, tweezers, some soldering picks, etc. when dropped into the pickle, which has free-floating copper molecules in it, will create an electrical current that can plate any metal in close proximity with copper – called copper flashing. Sometimes, this is something that you want to do but, most of the time it isn’t. If this happens to you – don’t Panic. It’s very easy to remove with Super Pickle.
- If you do put steel into the pickle, just take it out asap. The pickle will be fine. You don’t need to throw the pickle out! Really, you don’t!!! If you left the steel in all night, test it and see if you get flashing. Copper flashing usually occurs when little, unnoticed pieces of steel, like a stuck, broken drill bit left in situ or a piece of binding wire is accidentally soldered on. After pickling, you’ll usually see a small ring of copper around the steel. To fix this, remove the steel from your jewelry. Here’s a recipe for removing broken drill bits with Alum. For flashing (aka electroplating) to occur, the steel needs to be pretty danged close to the metal and it needs sufficient time to lay down a layer of copper so, if you accidentally dunk your steel tweezers into the pickle, no one needs to know! Just get them out of there and vow to never do it again! (Don’t forget to neutralize the acid on them though!). If you drop in a piece still wrapped in binding wire, remove it, finish whatever soldering is left to do, and mix up some Super Pickle.
- Sometimes, if I leave silver pieces in my (sodium bisulfate) pickle pot for too long (completely forgotten usually), a silver, matte, gray, “something” coats the silver. I’ve left pieces in for an hour or less and had this happen. I then must re-torch and re-pickle (sometimes twice) to remove the gray gunk. I emailed a few businesses about this and they replied that they thought the silver was being etched in the pickle and impurities were entering the tiny openings.
Types of Pickle
Sulfuric Acid Pickle
Some pickles, although not very common today, due to the dangerous nature of the acid, are made from a solution of between 5% and 10% sulfuric acid. They are now difficult to find and are usually seen in the manufacturing arm of the industry.
Citric Acid Pickle – a safe and non-toxic pickle
Citric Acid (anhydrous fine granular citric acid) is the new, “green” pickle but, there are a few disadvantages:
- It doesn’t last as long as the SB. Actually, it has a lot less longevity than traditional pickle.
- It can grow mold – if it sits cold too long. Maybe not so much if you heat it up daily. Mine sat for a few weeks and created a cloud-like mold. But, the mold was easily removable with a scoop.
- Because of the mold, some say it can smell funky although, I have never noticed any odor.
- It doesn’t clean the metal as fast as the Sodium Bisulfate pickle does.
- The higher the temperature, the better it works – which can result in burns from a really hot pickle – so, be careful!
- You still can’t pour it down the drain if there are copper particles present. You can tell if copper is present if your pickle is blue-green. Sterling, German silver, Argentium silver, most lower karat golds, brass, bronze, and copper are going to shed a few copper molecules in your pickle. You won’t get copper atoms in your pickle if using just fine silver or 24K gold but, since fine silver and pure gold don’t oxidize, there’s usually no need to pickle them in the first place. But, not always…
- Citric acid pickle is a safer, non-toxic pickle. You still need to wear a mask when mixing up a new batch though. Avoid inhaling the powder and I wouldn’t put my face in the pickle pot either! (You guys and your crazy ideas!) Splash some in your eyes and you’ll be crying to mamma! So, wear eye protection!
- Add more citric acid as the solution weakens or make up a new batch.
- MSDS: Causes respiratory tract irritation. May cause digestive tract irritation. Moisture sensitive. Causes severe eye irritation. May cause skin sensitization by skin contact. Causes skin irritation.
Suppliers of Citric Pickle or Citric Acid
You’ll go through a bit of this, as you need to replace it pretty often so, I recommend buying in bulk. It also molds – especially if you don’t use it every day.
BTW, I’m back to my sodium bisulfate pickle: it’s faster, doesn’t mold, and lasts forever (years, for a one-person studio).
Recipes for Citric Acid Pickle:
- One part citric acid to 6 to 7 parts distilled water.
- This recipe is from Jewelry Studies International. The author of the idea is Ronda Coryell. 1 cup hot lemon juice with 1 teaspoon of salt or 1 cup of hot vinegar and 1 teaspoon of salt. Ronda states, in the post, that this works well with Argentium silver.
Add Citric Acid to the water – Important!
Other types of pickle
Salt and Vinegar Pickle Recipe:
- Add one teaspoon of salt for every cup of vinegar. I’d use distilled white vinegar so that you can see what’s in the pickle. Works much faster when warm.
The recipe, from what I can discern from the web is: put in a big clump (handful?) of Food grade Alum aka (Aluminum Sulfate) into the water in your pickle pot. Stir. Works much faster when warm. If it is too slow, add more Alum.
Alum can be found at the grocery store (in small quantities for more money). At Amazon, 3.5 lb bag. Also found under Aluminum Sulfate on Amazon. You can put it on your hydrangeas too to increase the acidity!
Alum, in its various forms, is used in pickling (food grade), fixing dyes to fabric, baking powder, dying and tanning hides, and fire extinguishers, to name a few uses. Per McCormick (the Spice People) “It is a general-purpose food additive that functions as a firming agent.”
Don’t forget though! It is an acid with a pH value of pH 2 – 2.8. See below for information on pH.
Alum, Vinegar, and Salt Pickle
One tablespoon of alum into 1/4 cup of distilled water. Dissolve. Use 8 parts white distilled vinegar for every tablespoon of salt. Pour the water and alum into the vinegar. Heat to simmering (pickle pot on high) and then add salt to the mixture. Turn down the temperature and keep it warm in your pickle pot.
Black Magic Pickle
Amazon sells this pickle. I have never used it. People rated it 3.5 stars on Amazon but, often, one needs to take into account people’s level of experience when reading reviews. I have seen complaints about products that I know are great but, without proper instruction will rate poorly. So… Without having tried Black Magic, I can’t say anything about it. I have heard that it is supposedly non-toxic and if you’ve got steel in your piece (like a spring), it won’t cause copper plating. Here’s the MSDS on Black Magic Pickle.
It apparently contains sodium metabisulfite (aka disodium metabisulfite) and sodium sulfite. Sodium metabisulfite is used in homebrewing wine and beer to sterilize equipment and it’s also used for a zillion other things. When mixed with water it releases sulfur dioxide – the poisonous gas that comes out of Kileaua on a regular basis. It smells like hard-boiled eggs. Hydrogen peroxide is used as a replacement for Sodium metabisulfite because of the SO2 (sulfur dioxide) stench.
At the level jewelers are exposed to this chemical, it is considered a skin, respiratory, and eye irritant. MSDS on Sodium Metabisulfite.
Sodium Sulfite is a soluble sodium salt of sulfurous acid. It prevents dried fruit from discoloring among other things. Exposure to acids causes it to give up sulfur dioxide. Msds Sodium Sulfite. Hazardous if ingested or inhaled. An eye and skin irritant.
Sulfur Dioxide (a by-product when water is added to sodium metabisulfite). SO2 MSDS. Quote from MSDS: “Exposure to concentrations above the TLV of 2 ppm may irritate the eyes, nose, throat, and sinuses, resulting in choking, coughing, and sometimes bronchoconstriction. Concentrations of 50-100 ppm are considered dangerous. Exposures of 400-500 ppm are immediately life-threatening. Exposure to high concentrations may result in pulmonary edema and paralysis.”
As we all know, it’s “better living through chemicals” but, as we all also know, chemicals also need to be respected and safety precautions must be taken even when a product is billed as non-toxic or safe to use! Wear a mask, gloves, a chemical-resistant apron, and chemical-resistant goggles. Use adequate ventilation when mixing. Wear chemical goggles and also employ ventilation when using too.
Sodium Bisulfate Pickle
The most common pickle for jewelry making is composed of sodium bisulfate. Sodium bisulfate is also used as a ph reducer for spas so, you can purchase a product like Ph Down (Amazon) to use as your pickle. Pepe Tools sells Smart Pickle which is what I use now. There’s also Sparex No. 2– for gold, silver, and copper-based alloys.
Be sure to not purchase Sparex #1 which is used to pickle steel and iron! Check to be sure the label says: Sodium Bisulfate.
*Note: Be sure to read the specific instructions for your pickle.
Mix, approximately, one cup of ph reducer with a gallon of distilled water (Acid to water). Adjust amounts for your pickle pot’s size. You can determine how much it holds (if you don’t buy new and have that info readily available). Using a measuring cup, fill the pot to within one or two inches from the top with water. Record your results for future reference. (You don’t want the pickle overflowing when you put items in it!). So, don’t overfill.
*Note: there are 4 quarts in a gallon, so the ratio (don’t know if this is truly accurate as one is liquid and the other dry) for a quart would be: 1/4 cup of ph reducer per quart of distilled water. Fill to within 1-2 inches and then add ph reducer.
How to mix Sodium Bisulfate (aka Sparex #2, Rio Pickle, Safety Pickle)
Dressed for success: Mask, Goggles, PVC Gloves (link is for Glove recommendations), Plastic, chemical or PVC Apron.
- Use only distilled water
- Determine acid to water ratio from packaging.
- Measure water and pour into pickle pot.
- Either employ two studio-dedicated measuring cups or wipe dry the one you just used.
- Measure out your pickle.
- Slowly pour the powdered pickle into the water in the pickle pot.
- Turn on the pickle pot/crockpot. Set it on low.
- Stir with your copper, brass, or plastic tongs or a jewelry-dedicated plastic or wooden spoon.
- If you can’t wait anymore and there are still some of the bisulfate salts on the bottom, go ahead and use the pickle anyway. The pickle will work and the remaining powder will eventually dissolve.
Warning: (This is from Rio Grande’s site: “Sodium Bisulfate. Releases Sulfuric Acid, (here’s SciLab.com’s MSDS on Sulfuric Acid) on contact with water. Causes burns and irritation. Avoid contact with eyes, skin, and clothing. Do not inhale the dust. Do not swallow. Keep out of reach of children.”
Suppliers of Sodium Bisulfate Pickle
There are many more suppliers: Just Google “pickle for metalsmiths or jewelers”!
How To Remove Copper Plating or “Help, I Pickled My Silver Jewelry and Now It’s Covered with Copper”
Please see my page on Copper Flashing for more detailed information on this topic.
I use plastic, 16 oz., disposable medicine cups for this job. Using the clear, disposable measuring cup allows me to see how much of each chemical I am pouring in.
First and rather obvious: remove from the pickle, neutralize, and rinse the offending piece of metal. Next, read the following instructions for removing copper flashing.
- The mixture consists of 50% regular ‘ole, drugstore variety hydrogen peroxide (available in 3.5% – 6% concentrations), and 50% pickle from your pickle pot – as long as your pickle is of the sodium bisulfate variety! Here’s an interesting list of the different concentrations and uses of hydrogen peroxide by Daniel Carter. Who knew, (well, maybe you did), that it is also used as rocket fuel? (90% concentration). To learn more about hydrogen peroxide (you might be surprised at its uses and how it works), please see the For Additional Research section of this article.
- Insert copper plated piece into the mixture.
- Wait a minute or two.
- Put panic attacks away for now.
The pickle/peroxide mix can be reused. After a few hours (I leave mine to sit overnight) the hydrogen peroxide will no longer be active.
Maintaining your Pickle
If you use sterling silver, copper, brass, and many golds – including gold plate – or bronze, your pickle will eventually turn a turquoise green. Your blue/green pickle has molecules of copper swimming around in it, just waiting for some steel to show up.
Pickle lasts a long time but, over time, it will become dirty with dissolved dirt, metals, and cat fur. With just a little maintenance, your pickle can live a long and purposeful life.
When the pickle becomes slow, add more acid, if the pickle evaporates add more distilled water.
Keeping your pickle free of gunk will help to extend its life. I use a (jewelry-dedicated) Melitta Coffee cone and cone filters to strain the pickle and remove unwanted materials. It helps if your filters fit your cone.
Another way to extend the life of your pickle is to remove copper from the solution (if present). Ethical Metalsmiths employs steel wool to “soak up” the copper ions. The steel wool is then recycled. Read their article to learn more.
My copper removal test
I decided to try out Ethical Metalsmith’s steel wool idea and the following is what I experienced:
- I put a handful of steel wool into a small, plastic measuring cup with holes punched into the base and sides.
- A few minutes later, I opened the top to check on it and my studio was filled with a horrible stench – don’t know what the byproduct of copper, steel wool, and sodium bisulfite but the smell drove me outside. Perhaps, I should have done it outside, in the first place! (See below for an answer as to what was going on chemically.)
- (Image: after pickle (L), before pickle (R). The pickle “ate” the steel wool. While the steel wool was coated with a lot of copper, the odor was so nerve-wracking that I deemed the experiment worthy of further research.
- Does anyone know the name of the (off-putting) fumes that I created? Would love to hear your explanation. I’m guessing oxygen and…?
I recently received a response from Adrian about what was happening during this experiment. Here’s what he sent me, that he had found. Check out the supplied link for even more information on this topic:
Generation of hydrogen sulfide (H2S) gas when steel wool is soaked in an acid, the rotten-egg smell sharpens and during the rusting process the smell is even more prominent due to the high temperature. Hydrogen sulfide can be detected at very low levels; its threshold detection concentration (0.008 ppm1) is at least 500 times below the level at which it can cause adverse health effects.1 Hydrogen sulfide is a toxic gas, however, at low concentrations, health significant effects would not be expected, although the smell may cause annoyance or anxiety. At concentrations of 2–4 ppm, people may experience eye irritation and in sensitive individuals such as asthmatics, respiratory irritation may occur.1 Chronic exposure to low concentrations may lead to headache, fatigue and nausea. Hydrogen sulfide is broken down in the air and with low-level exposure, any that is absorbed is rapidly metabolized and does not accumulate in the body.1 https://assist.asta.edu.au/
Yet one more idea for disposal of cupric/copper sulfate at Finishing.com
Here’s a video on copper disposal from John Smith on Youtube.
Information on Copper in Waste Water
Copper can cause problems in wastewater, for aquatic life, drinking water, and more. Copper (copper sulfate) is most damaging in a liquid state, as opposed to in its solid form. It can be hazardous in a septic or water treatment system as it can destroy the beneficial bacteria used in processing our drinking water. The same is true for your septic system plus, there’s the hazard of runoff to one of the many bodies of water listed below (I am an obsessive person). Don’t dump your copper-saturated water or pickle into street drains, sewers, lakes, streams, brooks, cricks, brooklets, braces, aqueducts, pools, swimming pools, kiddie pools, reservoirs, lochs, mill ponds, sluices, tarns, firths, canals, oceans, inland seas, basins, water towers, holding tanks, puddles, the high seas, the 7 seas, narrows, Davy Jone’s Locker, straits, coves, gulfs, fjords, sounds, inlets, everglades, bogs, tributaries, creeks, rivulets, runnels, marshes, swamps, springs, sinkholes, bayous, bays, harbors, estuaries, channels, lagunas, lagoons, or your bath water, etc. for gawds sake! Dispose of your pickle in an earth-friendly, ethical fashion. Please.
Before disposing of your pickle you should neutralize it. This is done by adding a base (generally baking soda) to the pickle (which is an acid). My recommended steps are as follows:
- Wear protective gloves and a face mask or goggles.
- In a large (preferably) plastic bin, bucket, tank, or sink – large enough to completely hold your pickle pot in and the container you are pouring the used pickle into. Of course, in my description of how I just changed my pickle, I did all this in my stainless steel kitchen sink. Bad dog.
- You might want to have a bowl (jewelry only)handy, filled with water and baking soda solution (a couple of cups of water to a small handful of baking soda), for spills and neutralizing the filters. See #4.
- Using either a funnel or a Melitta and a Melitta filter, filter out any waste products from the pickle.
- Fold the filter over, to seal in the debris, and dip it in the neutralizing bath. Throw away.
- You may want to do this outside. Remember that homemade volcano project with vinegar and baking soda? Well, pickle and baking soda do the same thing. I used to neutralize, right in my pickle pot but, it always bubbled over the top and got everywhere. Place your crockpot insert into a larger plastic container before neutralizing.
- If you are taking the liquid, neutralized pickle to the hazardous waste store (ahem), or are storing it for a while, ensure that your container has a plastic – not metal – lid. Metal lids will be eaten by the pickle.
- Label the container as poisonous and write what is in the container. I like to draw a skull and crossbones on the container too! Drawing practice and safety practice, all in one fun exercise. (I need to get out of the studio more often!)
- Keep the top off until it is fully neutralized – let it sit for a bunch of hours. Because the gases that are being released will build up and possibly blow out a sealed container. Not good.
- Figure out your method of disposal: evaporation and crystal disposal, leaving it in its liquid state, or removing the copper ions with steel wool.
- Contact your local waste management company for their requirements and practices.
- Store evaporating pickle away from all living things – especially: animals and children. Keep the entire mess away from nature in general.
My recent Pickle Changing Experience
WARNING: PLEASE READ THE UPDATED INFORMATION AT THE END OF THIS SECTION! I just replaced my, almost 1-year-old pickle. I took photos of some of the processes I went through. Mind you, I’ve done this a whole heck of a lot of times but, this is my first “documented” pickle change-out. Thought I’d share.
My murky, filthy but, still working pickle. I changed it because I was getting a silvery coating on all the copper that I pickled. My suspicion is that it was free-floating zinc, no doubt present, because of a couple of pieces of brass that were left in the pickle a wee bit too long. I’m going to record the date, of the pickle change so that I’ll have an official record: 8/10/15 (I think). It’ll be interesting to see when I’ll next be changing the pickle (at least to me). I annually filter out the glop on the bottom and weekly add new distilled water (this is the instance where you CAN add water to acid because the acid is in liquid form and not concentrated). When the pickle seems to be slowing down you can add a little more acid. (1/4 cup?).
Working with cold pickle, I strained out the goop that was in the bottom of the pot. I used a Melitta and Melitta filters. I went through six, or so, filters because they became clogged with debris and didn’t drain fast enough for my impatient self. Here’s a shot of one of the filters:
I originally cleaned my pickle in the kitchen sink after I moved my sponge (except for the studio sponge used to wipe down the insert), dishes, foodstuffs, etc. out of the area. Now, I perform this cleaning chore in a plastic laundry tub.
I used a 2.5-gallon, plastic water jug. I cut a tab in the top to accommodate the Melitta and, to allow air to enter the container, later. My method of disposal will be the evaporation and recycling of the crystallized copper method. So, air circulation is essential.
Note: if you use a 2.5-gallon water container like the one shown, cut the opening on the spout end. I had this container leak pickle all over my studio counter. Not a fun mess to clean up!
I mixed the baking soda in a 2-cup measuring cup – a few tablespoons to the 2 cups of water. I slowly poured the mixture into the pickle, allowing it to be neutralized in small doses. I mixed up another 2 cups of neutralizer and slowly added that too. It took me about 20 minutes to fully neutralize the pickle. You can tell when it’s done: if you add baking soda and it doesn’t bubble, it’s neutralized.
Hazardous waste disposal companies
Some Notes on ph (Under construction 2/7/23)
What is a pH Level?
Ranked on a scale between 1 and 14, pH is a measurement of how acidic or basic a water-soluble substance is.
If a substance is considered neutral — such as pure water — it will have a pH level of 7. As the substance becomes increasingly acidic, the pH level decreases from 7.
Anything with a pH level above 7 indicates that the substance is alkaline. As the pH value increases, so does the alkaline level of the substance.
For example, lemon juice has a pH level of 2, coffee may have a pH level of 5 and rainwater has a value of 5.5. While hand soap may have a pH level of 10 and bleach may have a pH level of 12. From Stormasta.com.au, Examples of Corrosive Substances and Their pH levels.
Pickle is acidic. To neutralize the pickle, we use a base, ie baking soda or washing soda. Acids and bases neutralize one another (depends on the strength though).
pH below 7
- Citric Acid – pH 2- pH 6 for fruits. Citric acid pickle strength will depend on how much water it is added to. The more water (with its hydrogen atoms) the higher the ph (a weaker acid). Anhydrous citric acid is water-free citric acid. Read more here.
- Alum – pH 2 – 2.8. Food grade (Aluminum Sulfate) Can be used as a pickle for jewelry making. Alum dissolves steels so is useful for removing broken drill bits and burs from your metal. It does not affect aluminum or base metals. Article: What is Alum? at Corrosionpedia. See my video
- Ferric Chloride.
- Hydrochloric Acid – 1.1 pH at 38% concentration. Dissolves organic tissue on contact. Our bodies make hydrochloric acid as a digestion aid. Don’t use this as a pickle!
- Muriatic Acid (a diluted form of hydrochloric acid). Leaves behind chlorides. An innocuous residue.
- Sulfuric Acid – .5 at 33.5% concentration. Leaves behind sulfates. Sulfates break down concrete (calcium carbonate), corrode metals, and the crystals are sharp and can break through the skin.
- Sodium Bisulfate – pH 1.8. Has a pH of 3.6 – 4.6 in a 40% aqueous solution. Aka: sodium hydrogen sulfate. Used as a pickle. Ingredient in many jeweler’s pickles.
- Hydrogen peroxide – pH 4.5. but usually, an acid is added to stabilize it which lowers the pH to 3.5. Hydrogen Peroxide for consumer usage is usually sold as a 3% to 6% solution. Used in conjunction with warm sodium bisulfate pickle (50%/50% mix) to remove copper flashing from metal. (A pink coating over brass, bronze, sometimes silver, and lower karat golds). Called “Super Pickle”.
- Vinegar – pH is usually between 2 – 3.
pH above 7
Because pickle is acidic it needs to be neutralized and we do that with sodium bicarbonate or sodium carbonate.
Sodium Carbonate – ph 11- 12 – aka “washing soda, soda ash, soda crystals”
“Sodium Carbonate is the disodium salt of carbonic acid with alkalinizing property. When dissolved in water, sodium carbonate forms carbonic acid and sodium hydroxide.” Quote from PubChem Sodium Carbonate Compound.
“Washing soda” available at Amazon: BioGuard Balance Pak – 200. (99.8% sodium carbonate, .2% water).
Sodium Carbonate is a good neutralizer for ferric chloride used in etching copper-based metals. You can also neutralize ferric chloride with sodium hydroxide.
Sodium Bicarbonate – ph 8.5 – in a 1% aqueous solution – aka “baking soda, cooking soda, bread soda, bicarbonate of soda.
This is what I use to neutralize my sodium bisulfate pickle. Sodium carbonate is obviously a more alkaline chemical but sodium bicarbonate still works well and is readily available at the grocery store (or better yet, get the 15 lb. box/bag at Amazon. It will last a long, long time!
For additional Research
- American Elements: Copper Sulfate CuSO4
- Britannia.com. Hydrogen Peroxide: Chemical Compound. Written by the Editors of Encyclopaedia Britannica. Web. Date unknown.
- Copper.org for information on copper, copper sulfate, and other copper-related information.
- Educate-Yourself.org. Articles on Hydrogen Peroxide. Compiled by Ken Adachi. Web. Date unknown.
- Ethical Metalsmiths.org. Quote from their site: “Mission: Lead jewelers and consumers in becoming informed activists for responsible mining, sustainable economic development, and verified, ethical sources of materials used in making jewelry.”
- Ganoksin: Pickling Notes by Charles Lewton-Brain. Web. 2007.
- Hoover and Strong: Pickle: Cleaning up after Soldering by Sara M. Sanford, Web. January 1, 2008.
- Myfunhealthylife.hubpages.com. Food Grade Hydrogen Peroxide and its Uses. Daniel Carter. Web. 7/18/13.
- Northstar Chemical – Sodium Bisulfate 25%. Web. 2013.
Non-USA Suppliers of Pickle
Suppliers for European, Asian, African, Australian (and many, many others) locations, please see my webpage: Suppliers Outside the USA.
- Visit my YouTube site and go to my Soldering playlist.
Related Web Pages
- The 4 Steps for Successful Soldering
- About Solder
- Acetylene Gas – Tanks, Gas, Setup, Safety. This is a HUGE page. I cover regulators, the history of acetylene, transporting gas cylinders, Mapp gas, propylene gas, oxygen, leak checking, tank storage, hoses, flashback arrestors, and of course, all things acetylene, etc. Lots of information.
- On Flashback Arrestors
- On Pickle, Acid, Crock Pots, and Baking Soda
- Oxidation, Flux, and Firescale/stain Prevention
- Soldering 101
- Soldering in a Nutshell – my list of basic necessities for soldering.
- Torches – Lots of information on different torch types and their gases
- Using an Oxygen Concentrator for Soldering
Questions and Answers Related to Soldering:
- Q&A: Annealing – How long to hold your annealing temps? Kiln annealing.
- Q&A: Firescale/Firestain – See what others have had problems with and find the solutions!
- Q&A: Soldering Questions – One of the most asked after subjects. Many of my web pages have been inspired by soldering issues and questions.
- Q&A: Torch/Gas Questions – Portable vs. regular torches, problems with the torch, learn about butane torches, water torches, how to set up a torch safely, and buying torches.
- Q&A: Wire Questions. Balling up wire, tapering wire, work hardening wire, straightening wire, and more!