Grading & Restoring Cans

Grading & Restoring Cans
(revised: 12 April 1998)

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Not all cans are always kept in good condition, particularly older ones: some of them might have dents, or rust, or scratches, or faint colours, etc. A grading scale is commonly used, especially when trading, to state the condition of a specimen (which of course affects its value). There's no "official" grading scale, but most collectors use the following parameters:

M (Mint) : a perfect can, with no defects at all (or almost invisible ones).
1+ : nearly perfect, with very slight defects due to storage, transport, etc., which should be seen only from a close view of the can. Also indicated as "store condition"
1 : similar, but slightly more evident; still a good can if the specimen is old.
1- : a few details or small lettering might be lost or badly readable; dents might be a little heavier than in previous grade, or spoil the label; rust spots show on one or both sides.
2 : a can in poor condition, still displayable if rare or very old, but with dents or rust seen from far away.

MINT
no faults at all,
perfect

1 +
slight "storage"
dents & scratches

1
a few
rust spots

1 -
a nasty crease
across the label
1 - / 2
more evident rust
all over the can

2
rust spread in
the lower half

Lower grades are used for cans in poor condition, but of course such specimens should only be kept if very old or rare, or simply waiting to find a better specimen in substitution.

There are several ways to improve the appearance of a can and, in most cases, its grading level.

DENTS
HEAVY DENTS
The very first aid to a deep dent is to try to pop it out by pulling firmly the can's ends; in aluminium cans, this is often sufficient to reduce the damage, eventually helping the dent to smoothen by slightly pressing on its rims. Pressing the dent's rims should be done only if the dent is more superficial, during the above-said traction: an improper action could leave nasty creases (i.e. thin dented lines, difficult to reduce and almost impossible to take away completely)
Dents on 'steel' cans, instead, are too hard to pop out and should be treated as for minor ones.

MINOR DENTS
Despite many systems have been suggested, the best treatment is to use a thin, long wooden instrument with a smooth end (the handle of a kitchen spoon is probably the best you can find). It should be inserted and carefully brought towards the dent, rubbing it gently over the inside hump until it flattens.
Remember that for best results you need a good practice, so don't make your first attempt on a valuable can, but try first on a few spare ones.

SMASH !
two deep dents spoil the can, whose grade would now be no higher than 1- POP !
after popping out the dents and a first treatment, only slight traces of the damage are still seen
(grades 1 / 1+) WOW !
with a little further work, the can turns almost as new
(grades M / 1+)

This technique may give really excellent results (see above). Others, such as filling the can with water and then freezing it, or using an air pump to pop out the dents, or using any sharp-pointed implement, etc. might damage your can even worse.

RUST
Rust is probably the most difficult problem to cope with. It can ruin the paint, but it can even destroy the metal (either from the outside or the inside). On the "steel" type, treatment is often impossible because rust usually reaches the can through the paint, so that taking it away will only uncover grey metal. Small spots may be slightly improved on their fringes, where rust has covered but not yet destroyed the colour.
On Extruded cans rust usually forms small brownish patches and spots (quite unpleasant, especially on brighter backgrounds), which might still be treated if the thin layer of paint has not yet been worn out, or if rust has developed under the paint. In such case, maximum care should be taken to preserve the thin film of paint, as this could easily peel off or could be badly affected by a rough treatment. Also in this case a certain practice on spare cans should be carried out.
There are several substances that can be used to take away the rust:

Natural lemon juice: easy to obtain and harmless, it has a rather mild effect (useless on heavy rust) and it should be used rather concentrated to give some effect. The best thing to do is to warm the juice and then dive the can in it, leaving it for a few minutes; then take out the can, wipe it delicately with a paper tissue and see if some effect has taken place: if the rust is still there, soak again the can for another while, and so on. When the rust spots seem to have faded, rince the can with water and then dry it well (or the rust will come out again!).
Oxalic acid (it might be a little more difficult to obtain): it comes in the form of a white powder which must be diluted in water (about one spoonful in 1 litre of water is an average dose). Be careful not to breathe fumes: they are toxic! Leave the can in this solution just as with lemon juice, but remember that this treatment is stronger.
Hydriodic acid: I incidentally discovered this acid in several products which take away rust stains from clothes. Since it is a very strong acid (so carefully avoid any contact with eyes, skin, and do not breathe fumes), it should only be used on single rust spots.
Pour a drop or two on the spot, wait a few seconds, then wipe it off with a paper tissue: in most cases the brown rust colour will actually fade away under your eyes in just a few seconds. Repeat the treatment if necessary, but be very careful not to damage the paint by leaving the acid too long or by rubbing off the colour.
Always practice on spares, and eventually test the effects of the acid on a small part of the can: some paints might turn dull or become faint.

SCRATCHES

before and after treatment Scratches may be hidden by using a little paint. For some colours it is quite easy to find a perfect match (i.e. black or bright red), for others it might be very difficult (especially whites), for others it's almost impossible (metallic colours, silver, gold).

Again, practice on spares before trying on a valuable specimen, and always remember that a can should only be given a slight make-up to improve its appearance, but not be heavily repainted. Especially when trading, partners should be told if a can has undergone substancial restoration.

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Looking after cans
(revised: 12 April 1998)

Do cans need any special care? No, they don't, but a few hints are:

Any time you obtain a new can for your collection, it is better to give it a wash before displaying it: this will take away dirt and beer stains (which sometimes are responsible for rust spots), and will also improve the specimen's appearance.
Use ordinary soap (i.e. liquid soap for dishes) and a soft cloth; no hard rubbing and scrubbing: it could damage or scratch the paint. Rince well with water and carefully dry every part of the can ("steels" and extruded cans might rust if left damp), possibly leaving it a few minutes on a radiator or other heated surface to be sure it dries well.
There is no need to wash the inside of the can, and before displaying the specimen be sure no beer or water is left inside.

Some sticky stains from adhesive price labels, etc. might not be taken away by the soap; in this case try rubbing them off with a soft cloth or a paper tissue. If stains persist, ether or similar substances might be used, but since paint is easily affected by them (the finish could become dull or the colours could even be taken away), this must be done with extreme caution.
I strongly suggest to test the effect of the substance on a small part of the can you want to clean, possibly on the back or near the seam, where a slight damage would be less disturbing.
Pour a drop of ether (or whatsoever) on a paper tissue: it should be damp, not wet. Then run it over a small area (1-2 cm.) quickly and very gently, almost brushing the surface (don't press or rub) for two or three times. If colours shows no alteration, approach the sticky stain with the same technique, always acting very carefully.

Once you have cleaned the can, you might want to do a little "restoration" (see grading and restoring cans).

After that, a can requires no further care.

But remember:

Do not display cans to direct sunlight (i.e. near windows, in greenhouses, etc.) as colours would gradually fade away.

Cans should not be kept very close to electric light bulbs: constant exposure to a 40-60 Watt bulb from less than 15-20 cm./ 8 in. might cause fading as much as sunlight.

Cans should not be kept in damp rooms (i.e. with leaky walls, or near bathrooms and showers, etc.) or in open sheds, because rust would very likely develop on "steels".

"Steel" cans should also not be handled very often: this would cause tiny droplets of moisture, which later turn into small but nasty rust spots.

colour fading by light

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