The Conservation of a Maltese galley: A ship model from the 1770's.

03 Mar 2010

As an organics conservator at the National Maritime Museum I am responsible for conserving ship models - a highly specialised field in conservation. The museum holds the largest collection of ship models in the world, over 3000 models. I have recently treated a Maltese galley, which was made around the 1770's and is an example of the warships used by the Order of the Knights of Saint John in the Mediterranean during the Crusades. These ships would have been powered by a mixture of sail and man power. The main body of this model is made of painted and gilded wood and it is fully rigged with linen sails. There are a number of removable sections, 53 wooden oars and two miniature copper alloy canons. [[{"type":"media","view_mode":"media_large","fid":"219627","attributes":{"class":"media-image","typeof":"foaf:Image","style":"","alt":"GalleyImage 1.jpg"}}]] This model has been a particularly interesting project for me because of the wide range of materials and the different types of treatment that the galley needed. As well as general cleaning and repairing minor structural damage, there has been the tricky problem of stabilising the fragile textile sails while still attached to the model. With all the treatments I undertook it was necessary for me to find materials that were reversible. This is an important consideration in conservation as treatment should be reversible to allow for the object to be reverted to pre-conserved state if necessary. There was a thick layer of fudgy dirt - like soot - on the surface of the model. It's likely that a sticky layer of varnish made of linseed and industrial methylated spirits had been applied to the model at some point during its life and this varnish had helped to stick the dirt to the surface. I removed the dirt using a liquid spirit soap called Vulpex diluted in distilled water applied with small cotton wool swabs and removed with distilled water on cotton swabs. As the dirt was removed it revealed beautiful painted detail on the deck which hadn't been obvious before the model's treatment. A diamond and floral decoration and a painted surface implying wooden marquetry were found underneath the dirt. The same method was used to clean the large number of oars that were also extremely dirty. The stem at the bow of the ship had been repaired before using small nails. The nails were removed with pliers and the piece of wood adhered back into place with an adhesive. [[{"type":"media","view_mode":"media_large","fid":"219630","attributes":{"class":"media-image mt-image-none","typeof":"foaf:Image","style":"","height":"133","alt":"GalleyImage 4.jpg"}}]] [[{"type":"media","view_mode":"media_large","fid":"219631","attributes":{"class":"media-image","typeof":"foaf:Image","style":"","alt":"GalleyImage 5.jpg"}}]] The boomkins at the stern of the galley had snapped away. This was reattached with adhesive but the amount of loss to the wood and the tiny repair area meant that the repair would be vulnerable. I decided that a 'filler' should also be applied to this area as it would give the repair added structural support and make it more visually pleasing. I decided on a fill made of glass microballoons mixed with an adhesive called Paraloid, which is a material that can be removed easily with solvents such as acetone. [[{"type":"media","view_mode":"media_large","fid":"219632","attributes":{"class":"media-image","typeof":"foaf:Image","style":"","alt":"GalleyImage 6.jpg"}}]] [[{"type":"media","view_mode":"media_large","fid":"219633","attributes":{"class":"media-image","typeof":"foaf:Image","style":"","height":"146","alt":"GalleyImage 7.jpg"}}]] Microballoons are extremely tiny silica glass-bubbles that make an excellent fill material for areas of loss in wood giving the filler an elastic quality which allows for expansion and contraction of organic material. The microballoons were mixed into an adhesive and solvent solution; making a paste which has a similar appearance to icing sugar. I applied the mixture with a miniature metal spatula, working quickly as the solvent evaporated fast making the paste less flexible. When the fill had dried, I carefully smoothed the fill to be flush with the rest of the wood and used red acrylic paints to colour match it to the original wood. [[{"type":"media","view_mode":"media_large","fid":"219634","attributes":{"class":"media-image","typeof":"foaf:Image","style":"","alt":"GalleryImage 8.jpg"}}]] The most complicated part of the treatment was stabilising the damaged linen sails. The blue/green linen was very fragile and there were a number of tears and splits because the fibres were brittle and powdery. I decided to use an adhesive repair technique on the sails as they were much too fragile to be repaired by sewing. Tests were done on two types of adhesives - Lascaux and BEVA. Both are thermoplastic adhesives which can be applied as a liquid, left to dry and then activated with heat - this makes for cleaner repairs and easier positioning of the support textile. The result showed that BEVA was more successful at adhering the support textile to the sail and permeating the powdery fibres. The fact that the BEVA can be reactivated with heat means that it is a reversible and can be removed in the future if needs be. To apply the adhesive a support textile called Stabiltex was stretched over a frame and then the BEVA was sprayed onto the support textile using an artist's spray gun to give fine and even layers of adhesive. In most situations textiles can be treated flat on a level surface. However in this situation the bindings which attached the sail to the mast were too brittle and fragile to be untied. Localised humidification could have been used to untie each one individually but ultimately this would have caused more damage and the bindings would have had to be replaced. It was felt that the textile could be worked on while still in position. A support was made, consisting of a wooden fabric covered panel which allowed me to apply pressure and work on the sails while they were still attached. The Stabiltex was applied in strips to the sails and then using a heated spatula was adhered into place. During application, paper parchment was used in between the spatula and the support textile to protect the support textile and the sails from direct heat and stop the adhesive from sticking to the metal. [[{"type":"media","view_mode":"media_large","fid":"219639","attributes":{"class":"media-image mt-image-none","typeof":"foaf:Image","style":"","width":"","height":"","alt":"GalleyImage 13.jpg"}}]][[{"type":"media","view_mode":"media_large","fid":"219640","attributes":{"class":"media-image mt-image-none","typeof":"foaf:Image","style":"","width":"","height":"","alt":"GalleyImage 14.jpg"}}]][[{"type":"media","view_mode":"media_large","fid":"219641","attributes":{"class":"media-image mt-image-none","typeof":"foaf:Image","style":"","width":"160","height":"213","alt":"GalleyImage 15.jpg"}}]] Small areas of damaged rigging were replaced with fresh rigging and toned in with water based stain. In a couple of places removing the damaged rigging would have caused further damage or meant that large areas would have to be removed. In these cases Japanese tissue and adhesive repairs were used to bridge the breaks. Finally, the model was given a light clean with a museum vacuum and a soft brush and the oars positioned, making the galley ready for display. [[{"type":"media","view_mode":"media_large","fid":"219642","attributes":{"class":"media-image mt-image-none","typeof":"foaf:Image","style":"","width":"","height":"","alt":"GalleyImage 16.jpg"}}]] This galley is going to be on display at the newly refurbished galleries at the Museum of the Order of St John in Clerkenwell from spring 2010 onwards.