RESTORATION OF ANTIQUE CORKSCREWS AND TOOLS
(Adopted from an article by: Frank Kosmerl, 432 Hollybrook Road, Rochester, New York 14623, U.S.A.)
As corkscrew or tool collectors we are always interested in ways of cleaning the wooden and metal parts of our antique pieces. Our objective is to restore the wood by attaining a hard surface that protects the patina and the working marks that indicate age and use. Metal parts follow the same objective in removing dirt and rust. Whatever method or material is used the result must be reversible. There have been many procedures and opinions offered on this subject, making it difficult to decide which is best. Some experimenting is suggested. The following article is very interesting and have been taken from various sources as indicated.
RUST REMOVAL – A TIP FROM AMERICA
In response to many request for a method to restore rusted away maker’s marks on metal objects, I do offer a proposal. While this is not a way to restore a mark that is no longer present, it will clean up the metal to a point that all traces of a mark that may be present are clearly open to inspection. It is based on an article by my friend Ken Kinsey whose article on electrochemical rust removal was published in the June 1984 E.A.I.A. CHRONICLE. I have used this museum-developed process for four years to clean pitted iron and steel and recommend it highly.
– a 6/12 volt battery charger of at least 4 amp capacity
– a sturdy non-metallic, watertight container (plastic or heavy glass)
– household lye (this is called caustic soda in Britain) or baking soda (this is the electrolyte)
– a piece of stainless steel (this is the sacrificial anode)
– rubber gloves (especially if you are using the lye and have hand cuts)
– wire brush
– select a ventilated location. A loose lightweight plastic sheet over the bath may be desired to control/lye water vapour.
– mix the electrolyte with water in the container at a rate of approximately one heaped teaspoon to one quart of water (the ratio is very imprecise; but is based on a U.S. quart)
– connect the stainless steel to the positive clip on the battery charger and suspend in the water
– connect the rusted object to the negative clip on the charger and suspend in the water. (Total de-rusting must be accomplished in two stages since the clip should not be in the water, to maximize the effectiveness).
– select the 6 or 12 volt setting or adjust the anode/cathode distance to approximate a 2 amp reading on the charger meter. Zero reading or no bubbling around the electrodes means poor electrical contact.
– remove the article. The timing here depends on the size of article and degree of rust. It may vary from 10 minutes to 3 hours. Try 30 minutes. as a start.
– loosen the worst of the resulting blackened former rust flakes with an old butter knife or such, and wipe away most of the black sludge with paper towels.
– the remaining black stuff quickly dries and can be removed with an electric wire brush. The brush should be of a fine grade and well used or dull. There is no need to cut away the residue, the erosive action of a dull brush will do. After thoroughly drying, protect against more corrosion with a coating of hard drying wood finishing oil such as Danish oil, or with a hard wax.
The job is now finished! Some additional comments and explanations:
– safety is imperative when using lye. Keep away from eyes and cuts, and wash accidental contacts with plenty of water.
– avoid or minimize bath contact with wood or paint.
– the process is supposed to transform the surface layer (in microscopic scale) of rust back to the parent metal and thereby remove the adhesion for the remaining rust.
– this process cannot be overdone! It is great news for forgetful types, that leaving the tool in the bath for a weekend, etc. will not harm it.
– the resulting surface is left in a pleasant looking condition, not artificially zinc-looking like some topical rust dissolvers. Fastidious cleaning can result in light coloured metal while less ambitious cleaning will render a dark, “old iron” look after applying a protective coating.
– the solution will last as long as you can stand its rusty turbidity. It is considered safe to discard down the drain with copious water flushing. Water can be added as the bath slowly evaporates.
Editor’s note: Chemicals, water and electricity are potent combination. Think of safety and take great care when trying out this suggestion. Our tame scientist said that you should wear at least rubber gloves and eye goggles at all times when using the process.