Please see also the separate article on the lubrication of locks available here.
Eric Monk's book "Keys - Their History and Collection" suggests that "Unlike coins, no set rules exist (for restoration) and the ultimate finish can be left to personal preference". He goes on to say that very old keys which are extensively pitted are probably most effectively presented by merely removing any superficial scaling without attempting any great restoration. Indeed I would say that keys, and maybe locks also in that condition should be left untouched
The likelihood, if age dirt, rusting, etc is removed will be to identify the pitting and loss of metal that would otherwise have been hidden. Many collectors like to see keys untouched anyway with the patina intact. So if you want to do anything just spread a little oil over the key and lightly polish it in with a soft cloth and that will generally provide a nice finish.
The book adds that "Later keys can be fully finished and polished, and small needle files are helpful here, for the fine clefts of the bit. Some collectors prefer a 'blue' colour to the steel or iron, and this can be simply achieved by heating in a flame until the blue-black tint is obtained and then quench in water or oil". I've not tried this neither can I recall seeing any keys that have been treated this way. Perhaps the traditional collector would prefer it not to be done?
Dealing with how far to go with cleaning keys, perhaps it would be appropriate to clean out the bits with needle files as suggested, but what about abrasive material? Some collectors don't like wire wool; sand paper is likely to be frowned on; but a drill and wire wheel?!! I think it all depends on the type of key being handled - a rarity should require the least, if no attention. Less valuable keys might benefit from medium guage wire wool lightly applied to remove superficial rust. Wet and dry sandpaper cut into strips might also be used to lightly clean the shaft of a key with the bow end held in a vice (using a cloth to cover where it is held, to avoid damage). Straddle the sandpaper over the key shaft, hold both ends and lightly move the sandpaper crossways and down the key sides. When cleaning is finished wipe over the key with an oily rag, and dry with a clean cloth.
What about locks? Again the treatment of rarities should receive great caution, as any damage could be costly. If you want to risk restoration (and why should that be frowned on? Motor vehicle restorers do this with great abandon - why not us!) some of the things mentioned above might be used, then there are special products, like these below when the lock is taken apart:
- brass parts if heavily contaminated might be submerged in a proprietary fluid cleaner requiring dilution, such as Quadratech Jewel Cleaner for "clocks, watches, and instruments" (no ammonia is used) - see web site www.quadralene.co.uk; or No. 1 Concentrated Cleaning Fluid from Priory polishes, Priory Close, Newchurch-in-Rossendale ('phone 01706 229343)
- Give a face-lift with thinly applied black auto spray paint which is quick drying and adds extra cover where the original black 'japan' (shellac) coating is a little worn.
- I'm not sure of the product's name; a mildly abrasive rectangular block used by locksmith's is very useful for smoothing and removing light imperfections on (say) a flat brass case. Its shape makes it awkward to deal with irregular metalwork.
- For lock mechanisms that fail to operate due to dirt and the like, washing with paraffin and when dry spraying with WD40 will usually help, though might require more than one wash/spray.
In all cases carefully read the maker's instructions and heed their warnings! Remember that lock mechanisms do not ordinarily require oiling (it would create a build up of dirt, grease and grit). The locksmith's normal treatment is to use Graphite Lock Lubricant which comes in a plastic bottle with a puffer spray action.
Eric Monk touched on how best to display keys, suggesting a simple and effective way is to mount them on hardboard covered with adhesive felt, and frame this with light battens. His other methods proposed are to scatter the keys in an haphazard manner over stone chimney breasts, or to suspend them from the oak beams in an Inn.
An idea to display locks is to fit shelving using 6" wide plastic covered contiboard, ensuring this is well supported, then mount the locks on the shelves. Keys can be displayed on the front end with suitably placed tacks to hold them. Alternatively (or as well), glass display cabinets can be acquired either free standing or to place on walls. Perhaps other collectors may well have different solutions on which to advise how best to display our locks and keys.
This article is © Tony Beck, 2007.