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cleaning & restoring glass

N.B. While we believe all the information provided on these pages to be correct, we cannot be held responsible for any damage arising out of the use of any of the cleaning, repair and restoration techniques described, which are used entirely at the reader's own risk

page 1: cleaning

  • foreword
  • dirt
  • tools & equipment
  • cleaning
  • frosted glass
  • silvered glass
  • drying
  • limescale
  • rust stains
  • foreword

    There can be little more satisfying for a glass enthusiast than, having bought a disgustingly dirty piece of glass (preferably at a knockdown price!), to see it emerge from the soapsuds gleaming and sparkling, restored to its former glory. To look at its best, glass needs to be clean as much as it needs good lighting

    Most collectors are (quite sensibly) happy to pay a bit more and buy a piece already cleaned. Then they can be sure of exactly what they are getting for their money, with no risk of buying a 'pup'. That's why every piece of glass that we buy is thoroughly cleaned (by me!) before being offered for sale (with the exception of antiquities, which should never be touched)

    But for those on more limited budgets, or who don't mind taking a chance, there are bargains to be had in return for a little work

    So don't be put off from considering a piece of glass by the fact that it is very dirty, but do be aware that you are taking a risk by buying a dirty piece, and the price you are being asked by the seller should, therefore, reflect that

    If a piece is very dirty, but the seller still expects you to pay something near its full market value, I would walk away from it

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    dirt

    Dirt can cover up a multitude of sins, so dirty objects must be scrutinised for damage even more carefully than you would check clean ones. Chips can be obscured, small holes be filled in, worn enamelling and gilding covered, stains disguised, and even cracks hidden under a thick enough layer of 'crud'

    Wet pieces should also be avoided unless you have the wherewithal to dry them on the spot, as water will effectively cover water-damage and even quite severe scratching, and make small chips hard to spot. On our rounds, we often see wet decanters on offer, and I bet that most of them would prove to be badly water-stained when dried

    Some (unscrupulous) sellers will even resort to wiping the inside of vases etc. with vaseline, grease or oil in order to cover up water damage, so be prepared to stick your fingers in as far as you can to check for any oiliness

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    tools & equipment

    Unfortunately, you can't just go out and buy a "glass-cleaning kit", so you'll have to make up your own. Some items can be found in your local hardware store or supermarket, some you may even end up making for yourself. Below is a selection of tools that I find indispensable, starting with some basic 'must-haves', which can all be readily obtained:

    your basic washing-up brush

    standard washing-up sponge with scourer-pad (the sort recommended for non-stick pans is safer)

    NEVER USE SCOURER SIDE ON
    GILDING OR ENAMELLING

    'Brillo' or other soap-impregnated wire-wool pad.

    NEVER USE ON GILDING
    OR ENAMELLING

    dish-mop for reaching down into places your hand can't get into. Also for manipulating scourers and pads in confined spaces

    don't bin your old toothbrush, you will find it especially useful for getting the dirt out of cuts and fancy mouldings

    bottle-brushes are especially useful for narrow vases, decanters and, of course, bottles! The top should bend to shape easily

    teapot-spout brush. A miniature version of the bottle-brush for even smaller spaces

    Also very useful are these:

    some grit for swilling around inside decanters etc. (take out any big or awkwardly-shaped pieces, or they may get stuck in crevices)

    even better than grit, if you can find it, is lead-shot (obtainable from gun-shops)

    or, better still, special abrasive-coated shot, which are sold as 'Magic Balls' by Lakeland in the UK, and under the name 'Decanter Cleaning Balls' by a German glass company called Eisch (the coating will wear off in time, though)

    if you do use grit or shot, you will find it easier to use a sieve to tip it out into, and then rinse it off in before re-use. I suggest you don't use your normal one, as your grit or shot will get pretty yucky! I've seen some seriously weird stuff come out of the depths of old vases

    old paintbrushes are very useful - particularly narrow ones like this. Ideal for pieces with applied decoration, or the bristles can be cut shorter to provide a stiffer brush

    this is a really stiff brush that I found in an Ironmongers. I don't know what it was intended for originally, but it's great for shifting stubborn dirt

    an angled-head brush (I found this one in the dental-care section of my local supermarket), very useful for awkward nooks & crannies

    old artist's brushes can often reach into places other brushes can't

    yes, it's my magic bit of wire! With the help of a pair of pliers, this length of reasonably pliable wire (from an old coat-hanger) has been (a) bent into hooks to pull out bits of crud or lost scourers, (b) wrapped around (or taped to) brush handles to lengthen them, (c) sharpened into a chisel with a file to scrape off rust stains, (d) sharpened to a point for poking into tight holes, (e) used to loosen wedged grit and shot, and a ZILLION other things. Every home should have one!

    For when more desperate measures are required:

    an old hypodermic syringe - the ONLY way to get dirt out of the crevices amongst the fancy applied decoration on some old Stourbridge glass is often to flush it away under pressure. NOT recommended for the butter-fingered
    (you could try an old water-pistol instead)

    Also worth having at hand are:

    • a pair of long-nosed pliers, to grasp wire or brushes to give you a bit more reach (but be careful not to knock them against the glass)
    • the longest pair of tweezers you can find, for getting hold of wedged bits of crud

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    cleaning

    • Always wash your pieces one at a time in a rubber or plastic bowl, in case you drop one. You may wish to wear rubber gloves - I prefer not to, as I feel it makes my grip less sensitive
    • Use cool or hand-warm water only. Never wash (or rinse) glass objects in hot water. Although in many cases it may well be safe to do so, one day you will come across a piece with an internal weakness or microscopic bubble, and suddenly you will find the piece you were holding has now become several pieces! Ann was once washing a bowl when it literally exploded into tiny fragments like a car windscreen does
    • For enamelled or gilded pieces, use only washing-up liquid with soft sponges and brushes. A toothbrush may be OK if the dirt is ingrained, but go slowly and gently, and keep rinsing to check you're not doing any damage. Biological detergents, and abrasive creams or powders, are likely to take the gloss off enamelling & gilding, and, at worst, may remove it entirely
    • Pieces with graffito decoration (gold leaf laid on, then partially scraped away to leave a pattern) are particularly vulnerable. Use washing-up liquid with a soft artist's brush, cotton wool or a piece of soft cloth
    • Glass that is not enamelled or gilded can be treated surprisingly roughly without damaging it. Liquid biological detergents can be used to shift the most stubborn dirt, but be careful - they make glass objects very slippery!
    • Abrasive liquids like 'Cif' cream can be useful (usually applied with a toothbrush), particularly for fussily-moulded pressed glass, but never on enamelled or gilded surfaces, and you will need to take extra care in rinsing the piece before drying

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    frosted glass

    Frosted glass items have been exposed to the fumes of hydrofluoric acid, which destroys the normal glossy finish of glass, leaving microscopic pitting on the surface

    The main disadvantage of this is that the surface tends to become very grubby with ingrained dirt. The great advantage, however, is that you can go at it 'hammer and tongs' with the harshest of abrasives and things like wire-wool without the slightest fear of scratching it. Vigorous effort with 'Cif' paste and a toothbrush will get the worst off

    One problem, though, is that the rough surface (being effectively like sandpaper itself), if knocked against a metal object, can pick up metallic smears which may not be shifted by normal washing methods. See page 2, repairs & restoration for how to improve these

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    silvered glass

    Glass which has had silver electro-deposited on the surface looks particularly unappealing when dirty, as the silver tarnishes black. Like all silver, however, this tarnish can be removed by applying any normal (preferably 'long-term') liquid or cream silver-polish on a soft cloth and rubbing vigorously. Cotton buds are good for getting into tight areas

    If the tarnish is very stubborn, using the silver-polish with a toothbrush may get the worst off, before finishing with a soft cloth. Or, if you have one, use silver-polish on a felt pad in a power-drill at a lowish speed

    Once it has been thoroughly cleaned, your silvered glass will probably only need a light polish once or twice a year to keep it sparkling

    N.B. Sometimes the silver will not have been evenly electro-deposited over the whole pattern, resulting in thin parts which will become even more obvious once the article has been polished. Silver-polish is an abrasive, so thin patches are (unavoidably) made worse by using it. Be careful when buying to ensure the silvered pattern is a good, dense black all over

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    drying

    The only drying problems you are likely to encounter are when the object is, say, a narrow-necked vase, a decanter or something as fiddly as a toddy-lifter.

    For narrow-necked vases, either find someone with slimmer hands than you, or simply wrap your tea-towel around a piece of wood

    For bottles, decanters and similarly-shaped objects,

    • drain them (upside down) for an hour or two, to remove most of the water

    • take a sheet of newspaper, roll it up, twist it into a rope and push it as far into the object as possible (use a slim stick if necessary)

    • for smaller objects, kitchen towel or tissues will make a smaller 'rope', and for things as small as toddy-lifters, insert a long piece of parcel string (not nylon, synthetic or waxed - it must be absorbent)

    • within a day or two, your object will be completely dry

    N.B. Always leave enough of your 'rope' to get hold of when you want to remove it, and take care not to twist it so tightly that it begins to tear, or you risk leaving part of it behind. If your paper 'rope' does come apart, or accidentally disappears so far inside your object that it can't be hooked out (see the 'magic bit of wire' under tools & equipment on this page), don't panic!. You will simply have to fill the object with water until the paper disintegrates and can be 'wangled' or flushed out

    Some people recommend using a hair-dryer on a low setting for drying decanters, but I cannot imagine being desperate enough to risk it!

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    limescale

    Limescale can usually be shifted by using a scourer or soapy wire-wool pad. If it is severe, use any product described as a 'limescale-remover' (such as 'Viakal' for example) with a stiff brush or wad of wire-wool, repeating the process if required (N.B. always follow the safety instructions on the bottle). However, once the piece is dried, you may well find that the glass is water-stained beneath it (see page 2: restoration)

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    rust stains

    Rust stains are caused when an iron or steel object is left in water in a vessel (often by ladies who used a ball of chicken-wire, or a patent metal stem-holder, at the bottom of a vase to arrange their flowers - sometimes when a nail, pin or paper-clip has fallen in by mistake and remained undiscovered)

    These stains tend to be small and localised around the immediate point of contact with the wet metal. Although they are superficial, and do not affect the actual glass, they can be quite hard to shift using normal washing methods

    I find the best method is to get the worst of the rust off by scraping it gently with a sharp knife or scalpel, then remove the rest with a wire-wool pad and an abrasive such as 'Cif' liquid. For deep, narrow vessels, you will need to sharpen the end of your piece of magic wire to a rounded 'chisel' edge for scraping, then use a stick to manipulate a piece of wire-wool for finishing-off

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    .... carry on to   page 2: restoration