Lacquering the lidAugust 29, 2012 About my museum job, Blogs, Dissection and Resurrection Men
Subsequent to Jill Saunders’ recent blog post, Name that fibre!, in this entry Jill covers the application of lacquer to the lid of the iron coffin from St Bride’s.
With the corrosion reduced on the internal surface (See Keeping a lid on it) and the dust and debris removed from the outer surface and loose features secured (See Turning over a new lid), we were ready to lacquer the lid. Lacquering is seen as quite an unusual procedure in conservation, not least because of the significant aesthetic changes often caused. However, in the case of this object we felt it was important to help secure vulnerable decoration and protect the iron from future environments. The coffin and lid were in good condition, meaning there was still plenty of iron metal left ready to corrode if given half the chance! The open display conditions both in our Doctors, Dissection and Resurrection Men exhibition and in the St. Bride’s crypt, with uncontrolled humidity and temperature, were good justification for this measure.
Note the aesthetic change. The darker region is freshly lacquered.
For the lacquering material we used a conservation grade acrylic resin in a slow-evaporating solvent which would adhere to the surface, provide a degree of flexibility to prevent cracking and surface exposure, and form a tough coating. We also added a matting agent in an attempt to prevent the object becoming too shiny, as this is considered an undesirable aesthetic effect of lacquering. We felt after the second layer that the object was on the verge of developing a shine. If it was not for its known future of repeated access, movement and open display, we probably would have left it at two. However, given this context, we decided three layers would be wise. In addition to the general darkening effect (Fig. 1), the lacquer made decorative features, such as the remains of the leather border, stand out more from the surrounding iron. We felt that this was positive as it would make these features more understandable to the viewing public (Figs. 2 & 3).
Though secured fairly well by the lacquer, some details were raised up from the surface of the iron so that they could be caught, or were vulnerable to breakage (Fig. 4). We decided to fill these areas using a syringe and highly viscous conservation grade fill material mix, coloured with powder pigments to avoid aesthetic disruption.
Watch this space for the next entry covering the exciting identification of the coffin’s late owner: Coffin decoration & Mrs Campbell.