How to Permanently Tarnish Copper
- 1). Prepare the copper piece to be tarnished by cleaning, being sure to remove all oils and fingerprints. Be certain the piece is not sealed with a varnish, as this would need to be removed as well. The copper should have a bright finish before beginning.
- 2). Mix 2 cups white vinegar and 1.5 cups ammonia with 0.5 cup salt in a plastic container. Dissolve the salt thoroughly by stirring with the spoon, being careful not to splash the mixture.
- 3). Immerse the copper piece into the tarnishing mixture. Cover the container and let the piece stay in the mixture overnight. Agitate the container occasionally to ensure even coverage. If the copper is too large to immerse, brush the piece with the mixture using the nylon brush or a sponge. The tarnishing mixture must remain wet in order to work. If the piece starts to dry, put the mixture in a plastic spray bottle and mist the piece down occasionally. Note that the streaks and drips will be transmitted to the final verdigris effect.
- 4
Achieve the old penny look for pennies.Hemera Technologies/PhotoObjects.net/Getty Images
When the desired verdigris effect has been achieved, take the piece out of solution and allow to dry. Do not rinse the copper off with water until it is very dry. The finish will permanent, but can wear off from use or rain, depending on climate. The treatment can be repeated without re-cleaning the copper, as long as no oils or varnishes have been applied. - 5). Seal the piece with a polyurethane varnish to make the finish more permanent. The varnish may eventually peel and need to be replaced if kept in a very sunny location.
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