Recent News

 

 New Workshop set up for Gilded bronze: conservation, restoration and making of gilded bronzes (ormolu) 

Yannick Chastang is pleased to announce the setting up of a new metal conservation / bronze chasing workshop.  This is in response to increased demand for careful conservation of gilded bronze as well as the making of quality new gilded bronze (also called ormolu).  Yannick Chastang can now provide a top quality service for gilded bronze, from making of the moulds and supervision of the casting to in-house chasing and very soon in house gilding (electroplating and firegilding).  The employment of French-trained specialised metal workers means that Paris quality work can be achieved at more competitive prices.  Our hourly rate for making bronze is about a fourth of the hourly rate of a Parisian bronze maker.  This step will ensure greater control over the quality of our work without the need to sub-contract work to Paris. 

We are currently finishing the copy of the roll top desk of King Louis XV started by Francois Linke before the Second World War and, to date, never finished.  The work includes moulding, casting, chasing, mounting and finishing of all of the bronze mount decorations of this desk (as well as making the double faced clock and the porcelain plaques).  This is a mammoth and very complex task but a great privilege.

 

Some of the new bronzes made for the copy of the roll top desk of King Louis XV, originally made by Oeben and Riesener.  These photos show the casts before chasing and finishing 

Preparatory work for this project involved the analysis of brass alloys as well as the study of historical literature which enabled us to re-discover the true eighteenth century alloys in antique bronze.  Our bronze mounts are now cast in a local foundry where they use an alloy recipe very similar to that used during the eighteenth century.  The reason behind our research and behind the desire to use the same alloy is not dictated by traditionalism but simply because the eighteenth century alloy has many advantages over modern brass.  Most importantly, the metal is softer than modern brass making it easier to work and thereby reducing the time spent chasing by almost 30%.  Burnishing of the finished gold is also made easier and gives better results.  We primarily use electroplating to gild mounts, mainly for environmental and cost issues, but we are working very hard to recreate the look, thickness and colour of the more traditional ormolu which was generally fire gilded (also called mercury gilding).  Where budget is not an issue, fire gilding can still be done in France.   

Smaller projects include the making of new escutcheons and handles for a pair of Boulle desks that have recently been conserved for Chatsworth as well as keys and elements for other pieces of Linke furniture.   

Whether furniture mounts, candelabras, chandeliers or fire dogs, we believe we now have the means to make anything from modern originals to copies, be they from an existing model or based on a photo.  Please do not hesitate to contact us for advice on any project you may have. 

Chasing of a new escutcheon to replace one missing from a pair of Boulle marquetry desks owned by Chatsworth  

Photo showing only a small selection of the hundreds of punches (or ciselets in French) we use to chase the bronze mounts.  Many of these punches are antique tools which have been reconditioned for use in our workshop.  Antique tools possess the advantage of endowing the bronze with a much smoother and more authentic chasing.  As every style or every bronze mount requires special tools, if we don’t have the appropriate tool, new ones are made for on a  project by project basis.  

 England is among one of many countries that has exposed its gilded bonze to severe pollution from the time of the Industrial Revolution to the 1970s.  Many gilded bronzes in the UK, and in London in particular, have been irreversibly damaged and pitted by numerous corrosion spots caused by pollution.  David Scott from the Getty, a leading expert in the field of corrosion of copper alloys and treatment explains the black spots on many gilded objects very well:

 “Atmospheric pollutants such as sulphur dioxide can cause local dezincification (bronze mounts are made of brass, an alloy of mainly copper and zinc) leaving traces of zinc sulphite on the surface of the object, and these traces are rapidly oxidised to zinc sulphate.  Zinc sulphate is highly deliquescent, therefore even slightly elevated relative humidity can cause localized spots of condensation.  The zinc sulphate solution thus formed will dissolve more sulphur dioxide, which will be oxidised to sulphur trioxide, facilitated by the copper ions.  In the presence of the increasingly strong concentration of sulphuric acid in the droplets, together with atmospheric oxygen, more copper-zinc alloy will dissolve………….”

 Extract from Copper and Bronze in Art, corrosion, colorants, conservation by David A. Scott, the Getty Conservation institute, Los.Angeles, USA.

 Thanks to the Clean Air Act, pollution in London is now significantly lower with fewer atmospheric pollutants that could cause new corrosion spots.  Unfortunately, where there are existing spots of corrosion these will continue to spread thanks to England’s damp climate. The photos below illustrate deep corrosion spots spreading inside the brass. 

  

High magnification photo showing a cross-section of two corrosion spots on brass spreading beneath the surface and causing the distinctive “pitting” of the surface.  The brass metal is white on this photo.

 

If left untreated, corrosion will continue to spread beneath the surface of the brass causing irremediable damage to the object.  Careful cleaning techniques to address corrosion-related problems have been developed during recent years in our workshop.  This is opposed to the more traditional cleaning techniques which tend to use very strong cleaning products which can in turn damage the object.  Our objective is to use stable, neutral pH products and non-abrasive techniques, for example high pressure steam so that corrosion spots can be safely removed from most bronzes.  This technique avoids causing damage to the contrast of matt and burnished areas.  Gel techniques also enable the safe and careful cleaning of localised areas of bronze which may require further attention.  All of our techniques aim to preserve the patina on the back of the furniture mounts.  Great care is taken that newly conserved pieces of gilded bronze should acquire an agreeable aspect.  Newly cleaned gilded bronze can look too new or shiny in many collections and pieces are often treated using a technique known as “mise en couleur de l’or”, an 18^th century technique of applying coloured wax which can impart a golden tone improving dramatically the visual impact of the finished object.

 

 

Cleaning of gilded bronze using steam

 

 Typical example of gilded mounts before and after conservation.  The preferential corrosion seen before (top) on this original Boulle mount was carefully removed using techniques described above.  In many cases, gilded bronzes do not need to be re-gilt.

 

 

Again, please do not hesitate to contact us with regard to your gilded bronze, whether  they are furniture mounts, clocks or sculpture.  The problem of corrosion is very serious and should not be left untreated.

Recent projects

Over the last two years, Yannick Chastang Limited has conserved some important pieces:  a Boulle writing table from the Wildenstein Collection (the most expensive piece sold by Christie's in the 2005 London sale of the Wildenstein Collection), a Boulle cabinet on stand from Boughton House, collection of the duke of Buccleuch and Queensberry, and an important coffer on stand from the Lewis Walpole Library in Farmington (USA) .  We were also delighted to make new marquetry panels designed by Paul Fryer for his 2008 London show.  Enjoy the photos below.  

 

Yannick Chastang, November 2008. 

 

The Boughton Cabinet after conservation.  Copyright, The Duke of Buccleuch and Queensberry

The Wildenstein desk before conservation

 

 

Coffer on stand attributed to Boulle, The Lewis Walpole Library, USA

 

 

 

Collector's cabinet  for sale 

 

This cabinet is veneered with an egret marquetry of holly, pink ivory and other woods set into a background of

black ebony.  The water in which the egret stands is simulated by an interestingly marked piece of brown-speckled ebony.

The inside is veneered in a dramatically contrasting pink ivory and fitted with fourteen drawers.  More photos can be seen in the design section of this web site, in "pieces for sale" .