Chrome plating is a process that consists of applying a thin layer of chromium to a metal surface using the technique called electroplating (usually over a layer of nickel). The resulting result is an ultra-glossy decorative effect, resistant to corrosion, oxidation and very durable. However, sometimes the chrome can be removed for several reasons. For example, despite its duration, it may have been damaged due to wear, be unpleasant and therefore it is necessary to remove it. There are numerous techniques to remove the chromium layer, some of which use everyday materials, while others use highly toxic chemical solutions. Depending on the method you choose, use all necessary caution and observe the security protocols.
Steps
Method 1 of 3: Remove Chromium with Specialized Machinery
Step 1. Use an abrasive sandblaster
Sandblasting (for example, with sand, with beads, etc.) is a process by which materials are scratched with a spray of fine-grained powder or small pellets. Car bodies and construction companies often own such devices. Prolonged sandblasting can remove the chrome surface of an object; some finishing work will probably be required later for those hard-to-reach areas.
- It is advisable to use a relatively fine grit (for example, 400 grit sand) to avoid damage to the underlying metal.
- Keep in mind that the suspended powders, residues and chromium chips resulting from the use of the sandblaster can be toxic, so wear adequate protection on your face / mouth.
Step 2. Use an ultrasonic cleaner
It is a special device that uses sound waves to clean delicate objects that are difficult to treat, such as jewelry. Ultrasonic cleaning can also remove the chrome, in some situations (especially when the chrome has already been loosened a bit with another method). Place the chrome elements in the appliance tray and soak them in a cleaning solution (often plain water), then operate the tool according to the manufacturer's directions.
- If you use a solvent to dissolve chromium (for example bleach) instead of water, you can increase the effectiveness of the tool in removing. However, do this only if the solution you use does not corrode the device or in any case does not cause reactions of any kind. For example, as will be indicated later, caustic soda reacts with aluminum containers.
- Keep in mind that although ultrasonic cleaners come in a variety of sizes, most are only capable of holding relatively small items, such as jewelry, nuts and washers, minute tools, ornaments, and so on.
Method 2 of 3: Remove Chromium with Chemical Solutions
Step 1. Use hydrochloric acid (muriatic acid)
It is a strong corrosive acid. In high concentrations it can be used to remove chrome plating from metal objects. To remove chromium, a solution with a concentration of about 30-40% should be sufficient. Proceed as follows:
- Mix 1/3 hydrochloric acid with 1 part water in a bucket used only for chemical mixtures (such as a tough plastic bucket, etc.) to produce a 30% acid solution. Alternatively, purchase a premixed acid solution of the appropriate concentration.
- Dip the chromed object into the solution until you see the chromium peel off.
- Wash the item thoroughly with soap and water and rinse it before drying.
Step 2. Use sodium hydroxide (caustic soda) to strip the chromate from ferrous metals and carbon steel
Sodium hydroxide, also commonly called lye, is a caustic, highly alkaline chemical substance. It is able to dissolve different types of plating, including chromium, but reacts dangerously with water and aluminum, corroding the aluminum itself and producing flammable hydrogen. Hence, it should only be used on objects that do not contain aluminum as a base material. Proceed as follows:
- Mix about 220-350ml of sodium hydroxide with 4 liters of water in a bucket of neutral material (such as a sturdy plastic bucket).
- Soak the item you want to treat in the solution until you see the chromium come off. This operation may take quite a long time, so check often for changes to the object.
- Once the chromium removal operation is complete, wash the object thoroughly with soap and water and rinse it before drying.
Step 3. Perform an electrolytic inversion
Chromium is applied to the metal through the electrodeposition process, which involves the use of electric current to bind the chromium to the metal at the molecular level. By reversing this process, the chrome can be removed extremely effectively. However, this method can be very dangerous. Not only does it involve the use of electricity, but it also produces various toxic carcinogenic chemicals, as products of the reaction. Hexavalent chromium, for example, is a product extremely dangerous. So it's best to leave this to the professionals. The following steps are for informational purposes only.
- It mixes chromic acid and sulfuric acid in water in a ratio of about 100: 1. For example, you can add 900 grams of chromic acid crystals and 9 ml of liquid sulfuric acid to 4 liters of distilled water. Mix the solution in a suitable immersion container suitable for electroplating, material testing and / or chemical treatments.
- Heat the solution. Keep the temperature at 35-46 ° C if it is a decorative chrome. Keep the temperature at 49-66 ° C if the chromium layer is thick.
- With a cable, run a negative charge from a direct current source through the chrome plating solution.
- Connect the positive cathode on the object to be treated and immerse it in the solution. The positively charged outer chrome metal will detach from the object.
- Rinse the item by shaking it in running water, then rinse it again. Make sure you properly dispose of waste products resulting from the treatment.
Method 3 of 3: Remove False or Light Chrome with Household Materials
Step 1. Use a homemade abrasive product to remove particularly fine or brittle chromium
One of the simplest methods, which even a beginner can perform, to remove chromium is the simple mechanical action, i.e. scrubbing with an abrasive product. Mix baking soda or a solid cleaner with water to make an abrasive paste that can be scrubbed with a soft cloth until you see the chrome begin to loosen. This method may work best if the chrome plating is particularly thin or if it is a "fake" plating (such as a plastic painted with a "fake chromium" material). Again, a lot of "elbow grease" is needed.
Check for improvements often as you scrub. Clutching for too long could scratch the underlying material
Step 2. Use an oven cleaner
Some types of chrome (especially the plastic variants such as those you can find on model cars, etc.) can be removed with a normal oven cleaning product that you find on the market. These powerful degreasing solutions are usually found in cans in the form of a foam or liquid spray. Apply a generous layer of detergent to the object, then leave it to act for 10 minutes. Finally clean it by removing the chrome together with the spray product.
Keep in mind that some of these products can darken any underlying metal if left on surfaces for too long, so it's best to do the procedure several times for short periods until you get the desired results
Step 3. Dip the chrome element in the bleach
Another favorite method for model car enthusiasts to remove chromium is to take a bleach bath. In this case the chromed parts are simply submerged and left to rest. After about a day, depending on the thickness of the plating, the chrome loosens, or even peels off completely.
- The main advantage of this method over the others is that the bleach should leave any primer layer under the chromium intact.
- Once you have used bleach for this purpose, you must dispose of it properly and never reuse it (for laundry, etc.).
Step 4. Use brake fluid
Standard automotive brake products act as thinners in removing chromium layers from plastic objects. However, this method can take several days to give the desired results. In addition, the liquid must be handled and disposed of properly, as it is toxic. Rub the chrome item with brake fluid and let it sit for about 10 minutes before rinsing off. Repeat if you need to completely remove the chrome.
Remember that brake fluid can dissolve plastic, so be very careful when you decide to use this product on chromed plastic parts (or choose another solution)
Advice
Try to understand what material the chrome surface is made of, this way you will avoid damaging it
Warnings
- Using common household products does not make you safe from possible poisoning and damage to the eyes, skin, lungs. Always wear protective gear and have a first aid kit on hand.
- Hydrochloric acid, sodium hydrochloride and sulfuric acid are particularly volatile, toxic and carcinogenic; reduce risks by wearing all appropriate protective gear and developing a safety / first aid plan in case of an emergency.
