Maintaining Outdoor Sculptures: How to Clean a Bronze Statue and Protective Waxing of Bronze Sculptures

Maintenance will differ depending on whether your sculpture is:

  1/ Outdoors,

  2/ Indoors,

  3/ Or coloured (ie. not a traditional bronze colour).

The step-by-step statue cleaning guide you can find below applies to both Bronze Resin and to Foundry Bronze metal statues. The maintenance of both materials is the same.  


If you read nothing else before cleaning your statue, read this:

Do Not Use:

  – abrasive brushes or pads, 

  – cleaning chemicals, 

  – or paint,

to maintain your sculpture. As these can all damage the surface or the colour of your bronze statue, and could cause a need to repair it.

Maintaining an outdoor bronze statue starts with its placement


Maintenance starts with the placement of your sculpture! You can significantly reduce maintenance time on an outdoor sculpture by:

– Avoiding placing your sculpture beneath an oak tree. Oak trees leach tannins, which can stain marquees, outdoor furniture and sculptures.

– If you place a sculpture in a flowerbed, be aware that chemicals in the soil of the flower-bed (particularly soil enrichers) can cause colouration around the sculpture’s feet as rain splashes soil over the base of your sculpture.  Most often this presents as a green powder called verdigris. Placing the sculpture on a small slab of stone or concrete in the flower bed can minimise enriched soil interacting with your sculpture.

– If your sculpture has a lot of upward facing, deep texture, (for example, our life-sized Wiggling Spaniel), you may wish to site it away from trees that drop a lot of leaves, blossoms or berries, simply because the texture can catch a lot of debris.

– Similarly, moving your sculpture out from underneath branches frequented by birds will reduce the amount of bird poo on your sculpture.

Happily all these staining issues can be solved with a clean and a re-wax.

If your house is near the coast you may wish to clean and rewax twice a year, to protect against faster greening. And we recommend you not place a Foundry Bronze metal statue within seawater or in a swimming pool (see “Can Bronze corrode? The simple answer is no,” at the end of this article)

(Above) Bronze can be coloured green (called verdigris) when made. 

Intentionally coloured bronze should normally only be waxed using a clear wax, to preserve the patina (colour), while unintentional greening can be treated using the cleaning and waxing process.

(Above left) Greening (verdigris) can be caused by chemicals in the environment, like soil enrichers in a flower bed – reversible with the cleaning & waxing process

(Above right) Greening usually only affects Foundry Bronze metal statues, and it can be brushed off with a stiff nylon brush and then stained with a wax like Black Bison ‘Medium Oak’

A step by step guide for cleaning and waxing your bronze sculpture


Wait for a warm, sunny day to clean your sculpture. This will aid you in the waxing stage. (Alternatively, wax your sculpture using a liquid wax, or if you are cleaning it indoors, keep your hairdryer handy for later!)

Waxing your sculpture will protect the colour from the weather. If you purchased a Bronze Resin, the wax will also help protect the material from the elements and make it last longer. (Foundry Bronze metal is weatherproof, but the colour is still vulnerable).


Before you begin, select your wax.


If you have a coloured bronze, or if your sculpture is bronze colour and you like the way it is looking, then choose a natural or clear furniture wax. (We recommend Black Bison Wax – Natural).

If your sculpture is a bronze colour, and the colour is looking a little faded, or you have not waxed it for two or three years, choose a medium brown furniture wax. (We recommend Black Bison – Medium Oak).



Then prepare your cleaning area.


Some wax has a stain in it, which can damage furnishings. We recommend you clean your sculpture on a piece of cardboard if practical.

Open your furniture wax tin and allow the wax to soften in the sunshine. This will aid easy application later.

(Note – if you leave the lid on the pot and the tin gets very hot, the lid may pop off and cause a mess. )



Clean the surface of your statue 


First, use the bristles of a paint brush to remove cobwebs and debris from deeply textured areas.

Do not use abrasive brushes, nylon pads or wire wool pads to clean your sculpture.

Second, use a nylon brush to remove stubborn bird poo marks. A double headed nylon brush is provided in our outdoor cleaning set.

If you bought a bronze coloured Foundry Bronze metal sculpture and it has turned green in places (called verdigris), but you do not like the colour, then rub the green area vigorously with your nylon brush until most of the verdigris has come off in a dusty film. Select a wax with a stain, rather than a clear wax to deal with verdigris residue.



Clean your statue with water and towel it off 


Third, clean your sculpture using water and a soft brush or wet cloth.

Remember, do not use cleaning chemicals on your sculpture. Because bronze is coloured chemically (and using heat), cleaning chemicals on your sculpture can change the colour. 

Fourth, dry the sculpture with an old towel to prevent streaks.

If you do not dry the sculpture, dirt will reappear on the artwork once the water it is suspended in evaporates.



Wax your statue to protect it for another year 


Fifth, apply a thin layer of wax from the tin with a paint-brush. Careful: wax can stain! Avoid nice clothing and carpets!

Apply the wax with a stippling motion (a dabbing motion) to help the wax reach deeper detail.

There is no need to wax beneath the underside of the sculpture, which is in contact with the ground.

As you apply the wax, use the paint brush to push wax from areas where you have applied it thickly, to areas you have not reached yet. Applying the wax too thickly will cause the buffing stage to take longer and waste wax.

If you are waxing your sculpture indoors, or if the wax has not got soft in the tin, then you can use a hair dryer to speed the process.

Heat an area of surface of the sculpture with hair dryer until the wax turns more liquid when applied to the heated surface. This will help you move the wax around the surface of the sculpture more easily.

Important Warning: using a hair dryer speeds the waxing process, but if you are cleaning a Bronze Resin, you must be very careful not to overheat the resin by holding the heat on one area for a long time. Very high temperatures can cause cracking – so you may warm the area until the wax turns more liquid, but then must redirect the hair dryer.



Buff the wax off your statue to give it a nice shine!


Check that you have applied wax to the whole surface of the sculpture, (except the underside in contact with the ground).

Then leave the sculpture for 20 minutes, to allow the wax to cool.

If it is a hot day, it may not fully cool in all areas – but you can still proceed to the next stage after 20 minutes.

Buff the sculpture using a soft brush (like a boot brush).

If you have purchased a Bronze Resin, place your thumb over the end of the wooden handle, to avoid knocking the statue with the wood. Please take care, and remember that detailing can be fragile!

It is very important to thoroughly buff your sculpture, because residual wax can cause accidental staining of hands or clothes on a warm day.

Perform a final buff using a lint-free cloth. This will bring your sculpture up to an appealing shine.

Pick free any loose threads with fingers, or carefully with tweezers.

Your sculpture should now be well protected for another year.

We are really happy to hear from you if you have any questions about maintaining your bronze statue!

What happens when you find damage to your sculpture that looks like it requires repair?


If your Bronze Resin or Foundry Bronze metal statue has sustained a deep scratch or a small area of impact damage that is still visible even after a re-wax, consider our page: ‘Repairing your bronze statue / Scratches, Cracks and Accidental Damage’ <UNDER CONSTRUCTION>.


Can bronze corrode? The simple answer is no.


Neither Foundry Bronze metal or Bronze Resin corrodes in normal conditions.

There is a rare condition that can be suffered by a Foundry Bronze metal statue is chloride corrosion, known as ‘bronze disease‘. This sounds scarier than it is, because it is almost wholly limited to historic artifacts taken from the seabed and from shipwrecks.

For the purpose of this page on maintaining bronze sculpture, the best advice we can give is to avoid placing a foundry bronze statue in the sea or in a swimming pool.

If you do wish to place your sculpture there, consider a Bronze Resin, or even a non-cuprous (non-copper-based) resin like Stone Resin. Also, stone or concrete may also be preferable materials for in-pool or salt water statues. Excessive exposure to salt water or pool water by very near proximity (like beside the diving board, or a pool fountain) is also a good reason to use a different sculpture material. However, if you simply own a property on the coast or you have a pool somewhere in the garden, the waxing process will adequately protect your Foundry Bronze metal sculpture.

Cleaning an outdoor bronze statue on a warm sunny day can help with the waxing, and make the process more enjoyable! Indoors, a hair dryer can be handy when applying the wax.
Start by cleaning the loose dirt and cobwebs off your bronze statue with a paint brush. Remember to place your statue down gently on a soft surface, particularly as the detail on a Bronze Resin statue could be damaged if you knock it on a hard surface!
Use a non abrasive brush like a nylon brush to get the worst dirt and stubborn bird poo off your bronze statue. Don’t scratch your statue! A stiff double-ended nylon brush with a small and a larger brush end is great for getting stubborn dirt off a sculpture. (Also, you can use a fingernail!)
Clean your bronze statue using water. Don’t use cleaning chemicals on your sculpture because they may change the bronze colour in unexpected ways. Towel your statue off to avoid dirty streaks.
A warm day will soften the wax in the tin, making it easier to apply. Use a wax recommended for bronze like Black Bison ‘Natural’ and “Medium Oak” or Renaissance Wax. The wax should not have abrasive elements or cleaning chemicals in it.
Apply the wax to your bronze statue in a dabbing motion to ensure it gets into the hard to reach spots. Apply the wax thinly and brush it evenly around the statue – the thicker it is, the more work you’ll make for yourself with the buffing off!
Allow your wax to cool and harden before buffing the bronze statue with a non-abrasive brush. Leave it to harden for a day for best effect, though you can buff sooner than that if needed. Try not to leave any areas of thick wax, not least because these will soften on a future warm day and endanger clothing!
After cleaning and waxing your statue should look glossy and ‘good as new’. You have protected your statue for another year, and for a Bronze Resin statue you have also helped protect the sculpture material. Be careful! When you carry the newly waxed sculpture, or if it is going onto carpet, the new wax can stain. Wear work clothes to move it, and wipe the base of the sculpture if taking it indoors.