We were very lucky to have expert advice given to the project by a conservator at the Museum of English Rural Life, about how best to label the tools, which we will outline here for the benefit of others who may embark on similar projects.
N.B. One thing that did not work for our purposes, in that the tools will be used rather than displayed in glass cases, was to paint the tools with a layer of clear lacquer before painting on the codes. Though it means the code will be removable without causing any damage to the tool, it is too fragile for regular handling.
Labelling can be done using Tyvek labels, these will last long even in a damp environment. You’ll need to use a permanent ink pen as normal pens will fade over time and you’ll find it difficult to write on Tyvek with graphite pencils. Do not attempt to stick any labels on objects, as they won’t last, get separated from the object over time and might even damage the object (glue migrating into porous materials, corrosion from glue on metals).
Numbering is a bit more complicated as it involves many different options depending on substrate and willingness to go the extra mile.
If an object comprises of different materials, you’ll always put the number on the least porous material, so on a hand tool the number will go on the metal.
Remove corrosion or dirt first and apply a strip of consolidant using a brush. This strip needs to be slightly bigger than the number you’re going to apply. The consolidant is either Paraloid B72 in acetone or Paraloid B67 in white spirit. Neither of which come ready mixed. You’ll have to buy these in granular form and dissolve them. This takes some effort, but once you have the solutions made, they should last a long time. The B72 in acetone, is quicker to use as the solvent evaporates at a greater rate, the B67 takes longer to cure (depending on the temperature, sometimes up to a day as opposed to 30-60 minutes for the acetone). However if you are reluctant to purchase these ingredients, you could take the easy option and buy some clear nail varnish. This obviously dries very quickly and will speed up the process considerably. Further advantages to nail varnish and B72 in acetone is that the solvent won’t penetrate far into the substrate, white spirit obviously does.
The reason for application of the consolidant is to prevent the ink from penetrating into the substrate. We normally use water based ink (like Daler Rowney acrylic artists ink), black or white, depending on the colour of the object. Some people like to apply a second coat to seal the ink in, I normally don’t bother.
Porous materials like wood and leather need careful consideration as to where to put the number. On weathered wooden surfaces you may need to apply several coats of consolidant to obtain a smooth surface. On leather you apply the consolidant on the smooth skin side, not the rough flesh side. Glass and ceramics are similar to metals. You should not apply the B72 or nail varnish on painted surfaces as it may interact with this (dissolve).
Paper and card are numbered using a HB graphite pencil and no consolidant. Plastics and rubber materials cannot be numbered, as no ‘reversible’ method has yet been devised. In that case you’ll need to attach a label or rely on a good database description.
I would never number the metal part and the handle separately. It is one object, and whether the handle has been replaced or not is neither here nor there. You would note that down in the database or the object file including reasons for replacement.
Where you put the number on the tools is difficult to describe with a hard and fast rule. Obviously not where you will handle the tool nor where it will be worn through use. The reverse and in less conspicuous places are probably best.
The code system is entirely up to you, though I recommend to keep it as simple as possible. The longer the number, the more work you create and the more space it requires on sometimes relatively small objects. At MERL the number consists of the year of acquisitions and a consecutive number: so 2014/1. If an object consists of several parts the numbering becomes: 2014/1/1 and 2014/1/2 etc. However (and this can easily be confusing) when does an object become a collection of parts? For instance a tool in a box: the tool gets number one and the box number two, and even when the box consists of two parts they get separate numbers.
With this particular collection of objects, which will be used, possibly over a long period, you are pretty much gearing yourself to the longevity of the objects. Nothing wrong with that, but use means wear and tear and therefore loss of material. I would therefore opt for the easier method of numbering and not get hung up on very long term preservation of the label.
As to conservation / restoration tips, this is where it gets even more complicated. In short: as you are going to use the tools and store them in a damp barn, you will need to opt for a belt and braces treatment as opposed to the gentle museum conservation route. Waxoyl and Shell Ensis fluid (commercially available) are good alternatives to 3 in 1 oil. The problem with 3 in 1 is that it remains sticky which will allow dust to adhere to the surface. Dust is hygroscopic and corrosion will form (but only in the long term). The fact is that you’ll probably have to introduce a rolling program of checking and re-applying preservatives.
If it is an open store you will need to guard against woodworm: we use Wykamol in the museum as it is one of the few insecticides you are allowed to use and is available without needing a license.