Zinc plating is a common coating on hardware items such as screws and nuts. It is primarily used to provide a protective barrier against oxidation. However, if this plating is incompatible with other types of hardware, as can often happen, it must be removed. A caustic bath in a highly concentrated acid or base will allow you to remove zinc plating from your hardware so that it will be more useful and more compatible with other components.
Things You'll Need
- 20 percent Hydrochloric Acid (HCl) or Sodium Hydroxide (NaOH)
- 4000 ml glass beaker or other large, open topped glass vessel
- Glass ladle
- Glass or ceramic plate
- Universal indicator
- Vinegar or Milk of Magnesia
- Latex gloves
Add the HCl or NaOH to a glass beaker until there is a large enough volume to submerge your hardware completely. Be sure to wear latex gloves while handling acids or bases as these substances are extremely corrosive.
Place the items you wish to be stripped in the acid or base bath. Let the items sit for 12 hours.
Use a glass ladle or other corrosive resistant tool to remove the items from the bath. If the glossy zinc coating is not fully removed, submerge the items again for an hour and check them again.
Place the items on a glass or ceramic plate and allow them to air dry. If you wish to speed the drying process, wipe them down with a paper towel, being sure to wear your latex gloves for protection.
Add the universal indicator to the corrosive bath. This will allow you to determine the pH of the bath and thus the steps you will need to take to neutralize it. If you are using HCl, the mixture will turn red (indicating an acidic solution), if NaOH is being used, it will turn blue or purple (indicating a basic solution.)
Add Milk of Magnesia to the bath if you are using HCl. If NaOH is being used, add vinegar. Add these substances until the bath turns green. This will indicate that the mixture is neutral and is safe to dispose.
- Photo Credit zinced screws on white image by amlet from Fotolia.com
How to Remove Rust From Galvanized Steel
Galvanized steel is designed not to rust, so if you have a galvanized steel item that has rusted, it means that the...
How to Remove Moss from Roof Shingles with Copper Sulfate
Moss often grows on roof shingles because leaves that fall on the roof from overhanging tree limbs retain moisture. Copper sulfate works...
How to Remove Protective Coating
Some eyeglass lenses have protective coatings to prevent glare and protect the eyes against UV rays. If the coating gets a scratch...
How to Strip the Zinc Plating From Bolts
To protect bolts from rust, manufacturers add zinc plating. This coating is shiny and may stand out on construction projects that are...
How to Remove Anti-Reflective Coating From Eyeglasses
Remove the AR coating from plastic lenses using glass etching compound. To remove it from glass lenses, use isopropyl alcohol.
How to Remove Chrome or Nickel Plating From Steel
Many antique items have been coated with chrome or nickel plating, and the owner may wish to restore it to the original...
How to Use Vinegar & Salt to Make a Penny Disappear
Cleaning pennies with salt and vinegar is a classic elementary school science experiment. Using the same principles, and a little patience, it...