When caring for antiques and especially Antique Ceramics and Glass we are caring for some of our most delicate possessions, however, our ceramics and glass can also be among the most hard-wearing. Cleaning antique ceramics or antique glass is relatively simple, but repair is rather more involved. If your antique ceramic or glass is greatly valued for sentimental reasons or if it is worth a significant amount then always take it to a professional repairer or restorer as soon as possible.
Hold the item by the main part of the body. Never hold or lift an item by the handle. The handle of an item is the weakest point. Many time there is damage to a handle that cannot be seen, holding or lifting the item by the handle can cause further damage or may destroy the item altogether. Accidental breakage is probably the highest risk factor with antique ceramics or glass and you can avoid this by careful handling and cleaning. Always make sure your hands are clean and dry before handling antique glass or unglazed ceramics as greasy fingerprints can leave indelible marks.
Don’t wear cotton gloves while handling antique ceramics or antique glass as your secure grip will be less than usual and always pick up an antique item by its soundest part. Make sure you take care of loose parts such as lids or covers and check for weaknesses caused by restoration and cracks.
Whenever breakage occurs, as it surely will, wrap every broken piece separately in acid-free tissue and collect even the smallest shard. Resist any temptation to try and fit the pieces together yourself as you will damage the nice crisp edges.
Do not be tempted to repair a valuable antique piece yourself, as modern adhesives that are strong enough to form an effective join are usually irreversible. If it’s glass then it’s rare this can be mended invisibly, unless the break is at a convenient joint. However, synthetic resins with a refractive index similar to that of glass are now available and cracks and holes can be filled. Chips can sometimes be ground out with a minimum loss of value. And a professional restorer may be able to recreate missing pieces such as a decanter stopper or the blue glass liner of a salt. Ceramics can be so skillfully repaired with modern adhesives, and then repainted or glazed that the original damage is almost undetectable. However, the restored area may discolor over time, especially if it’s exposed to water and some glazes can never be faithfully reproduced.
Without the proper skill, time and patience an amateur repair will always appear that way and a more complicated and expensive professional repair may be needed at a later date.
Do not use abrasive or harsh cleaners. If the porcelain or pottery item is very dirty, use a soft sponge to gently wipe clean. Do not use any kind of tape on lids or main body of the piece – peeling it off may remove enamel or gilding. Keep antique porcelain and pottery pieces behind glass.
There are several simple steps that can be taken to bring out the best in your art pottery and ensure that you are able to display your pottery in its original beauty. Many times we buy collections or individual pieces that have been poorly stored and have more dirt, grime, and stain than we would prefer. In an effort to bring these pots back to their original beauty we have experimented with countless cleaning methods with mixed results. The following is a summary of methods that have either been tried or heard of being used successfully to clean antique art pottery. Please use any of these methods at your own risk as all pottery and associated dirt, grime and stains are different. What works in one case may not be at all effective in another and may, in fact, result in damage to your item.
Cleaning dirt and grime from antique art pottery: Soak the vase for at least 24 hours in hot water and ammonia mixture. Typically a cup of ammonia can be used per 2 gallons of water. Some people have reported additional success by adding Spic and Span to the ammonia/water mixture. Removing silver or pencil marks from antique art pottery:
The best thing we have found to remove silver or pencil marks is metal polish. To use metal polish to remove marks from your art pottery, simply put a little bit of the polish on a rag and rub the silver marks. The rubbing process does typically take a considerable amount of elbow grease but is definitely worth the effort in bringing your art pottery back to factory fresh condition. After the silver marks have been removed, use the clean part of the rag and buff the remaining polish off the vase. Other methods that are somewhat effective in removing silver or pencil marks from art pottery include: “Barkeeper’s Friend” with a sponge and warm water and using a pencil eraser to attempt to erase the marks of the art pottery.
Removing mineral deposits
The most effective thing we have found to remove mineral deposits such as calcium, lime, and rust stains from art pottery is to soak the vase in full strength white vinegar. For lighter mineral deposit staining a day or two of soaking the item in the vinegar is all that is necessary to the remove the mineral deposits. On art pottery that has extensive mineral deposit deposition extended soaking may be required. At times the extended soaking may take weeks to remove the deposits from your art pottery. On art pottery requiring extended soaking to remove lime or calcium buildup we often rub the problem deposits daily with a butter knife to break up the deposits and thus allow the vinegar to better penetrate the buildup. For extended soaking, we also change the vinegar regularly. Obviously if doing this you must be very careful to avoid damage to your art pottery item.
After you have got the pottery as clean as you can, wash the vase with soap and warm water. You will then need to soak your art pottery in tap water until the vinegar smell is gone.
Other methods, which we have not personally used but have heard to be successful in removing minerals deposits from art pottery, include Lime Away, CLR, and baking soda and water mixture. Obviously, the risk of damaging the finish glaze greatly increases as the harshness of the chemicals you use increases. So proceed with caution and use any of these methods at your own risk.
Removing darkened crazing
Hydrogen peroxide can typically be used to lighten darkened crazing on glazed art pottery. Over the years we have heard of numerous techniques for using peroxide to effectively lighten darkened crazing. In general, the procedures that are most reported to be successful go something like this.
Use only 40% hydrogen peroxide and do not dilute. The lightening process will not be successful if you use a lesser strength solution. Be sure to use waterproof gloves and protect all exposed skin. Soak the pottery vase in the peroxide solution. Use a small container that can be sealed. Others have reported success with soaking clean rags in peroxide and wrapping the vase in the rags and then placing the vase in a large, sealed baggy. The process can take weeks and even months in some cases. Since the peroxide loses its strength over time if it is exposed to the air, it is important to use a sealed container and to change the mixture from time to time. If using cloths in the baggy, pre-soaking them every few days should be sufficient. Periodically check the pottery item to see if the crazing lightened to a satisfactory point; if not continue soaking.
Removing glue and sticker marks
We have found the De-Solv-it spray to be very effective in removing old sticker stains, glue and related marks on glazed art pottery. Typically you can just spray the De-Solv-it on a clean rag and rub on the problem area on the pottery and buff clean with a soft cloth. Also, acetone has been used effectively on a cloth to remove stickers and glue from art pottery but acetone may damage any repairs on your pottery so be careful if you are unsure if your piece has been repaired.
Removing paint specs
Many times when we purchase art pottery items in addition to the dirt and grime accumulated over the years they come with extra drops of paint. Acetone is very effective at removing these paint other glazed art pottery. For thicker and aged paint specs you sometimes need to use a safety pin or needle scuff or flake the paint to allow the acetone to work into the paint.
You may be able to shift tide marks from glass such as wine stains in a decanter with a solution of denture cleaner and warm water or with acetic acid or vinegar. Just leave your chosen mixture in the glass for 24hrs then rinse, drain and dry thoroughly. Methylated spirits or pure alcohol can be tried for stains caused by alcohol-based perfumes, but change the alcohol every hour or so until the stain has gone. Ammonia or ordinary household bleach which contains chlorine will remove stains on most antique glass, as long as there is no gilding or other fragile decoration.
NOTE: This is not suitable for ceramics as it may aggravate the stain or cause permanent discoloration.
Instead for a soft or hard-paste porcelain surface with no luster decoration, obtain twenty volume hydrogen peroxide from a chemist and add a few drops of ammonia. Wear rubber gloves and dampen strips of cotton wool in the solution, then lay them over the stain or crack and leave for about an hour. Do not allow the strips to dry onto the surface.
For improved results, the item can be placed in a plastic bag to retain the moisture. Check regularly, and you may have to renew the dressing several times. Enamel painted decoration on ceramics comes to no harm using this technique but do not use it on pale blue or greenish-blue 19thC. Enamels, as they can disappear.
For more stubborn stains wipe with a cloth moistened with warm water with a few drops of methylated spirits and some household detergent, then rinse with clean water using a well rung out chamois leather. Protect the frame with a piece of thin card.
Where grime has built up on stained or leaded windows brush it off gently with a soft bristled brush and as long as the surface is stable, clean with cotton wool moistened with the same methylated spirit and a detergent solution used for mirrors.
Sunlight, bright light, humidity or variable temperatures shouldn’t affect your antique glass or your antique ceramics but if they have any restored areas then bright light or water can weaken, discolor or stain the adhesives used.
If displaying valuable antique glass or ceramic objects in a cabinet or on a shelf make sure it is stable.
Vibrations caused by normal household movement can cause the pieces to walk and fall off narrow edges. As added security and to protect your surfaces set felt or chamois leather pads that can be cut to fit, beneath valuable antique items.
Always put a separate container within a precious antique vase before setting the plant or cut flowers inside as a protective pad between the inside of the antique vase and the container to guard against water stains.
Only use sound un-cracked plates or chargers as wall hangings and always use acrylic or plastic coated wall fittings that can be adjusted to fit the plate.
- Never, ever use metal plate hangers as they can corrode or if too tight can bite into the plate.
- Never immerse low fired earthenware such as delftware, faience or majolica in water. They may have an unglazed foot rims or old cracks or chips which expose the porous surface beneath the glaze. Much safer to wipe them with cotton wool moistened with some mild soapy water.
- Items requiring special care – assuming they are objects of antique value and kept for display only, and which it is advisable simply to dust regularly are.
- Crackle glass; the fine surface cracks can be aggravated by moisture.
- Unglazed low fired pottery; water and impurities will absorb into the porous body
- Ceramics with metal or ormolu fittings or items restored or mended with iron rivets or staples.
- Ceramics with gold leaf or delicate over-glaze decoration which might flake easily.
- Never use commercial glass cleaners on mirrors, stained glass or leaded glass
- The chemicals in them can act as a solvent on a glass that is stained with a colored varnish, on a gilt or varnished frame, and on lead or putty.
Antique Glass Chandeliers
Before dismantling a cut glass chandelier for a major clean, photograph the piece intact, and work out a system of identifying the luster so that you know where to replace them. Turn off any electrical connection and don’t allow water to seep into the hollow branches of the chandelier. Wash the glass lusters in a detergent solution, checking that the metal hooks are sound, rinse thoroughly and dry immediately to prevent corrosion of the metal, then polish with a soft lint-free cloth.