The Conservation of a Terracotta Barbary Pirate


Before treatment

It is unknown whether this terracotta bust was made in the early seventeen hundreds or in the 19th century but when I was first asked to look at it most of its detailed stamp decoration and fine details were obscured by aeons of neglect.


The "Barbary Pirate" belongs to The National Maritime Museum (Greenwich), having been acquired in 2011 and conserved for display in 2018. A V&A report on its costume notes "the elaborate dress of the sailors of Rabat-Sale [on the Atlantic coast of Morocco]. The many layers of the garments which would have been of felted cloth, richly decorated with gilt plaited braid couched in foliate designs, were of Turkish influence, and introduced by the corsairs who regularly terrorised the North African Coast."


This richly decorated bust had been repaired in the past and showed also signs of having been polychromed. The museum's goals were to understand the extension of its repairs and improve their appearance, as well as to clean the detailed surface decoration and to prepare the sculpture for display in the permanent galleries.


How was it made?

The bust is made of two terracotta sections joined at the neck with one internal ceramic dowel, set with a cement-like material reinforced with burlap.

One section comprises the head, thickly potted, and with expressive physiognomy detail; the other from the neck to waist, also thickly made and with visible cracks due to clay shrinkage during drying/firing.

Eye examination revealed two distinct layers of clay: a thick orange clay appears to be coarsely mixed with grog for strength; this is skimmed with clay of refined texture and homogeneity. Onto this top layer, the decoration is largely achieved by the use of several stamping techniques in addition to hand and tool modelling.


Conservation treatment

After careful examination of the attachment apparatus at the neck level, it was decided not to reverse this joint. In addition to the known cement-type mortar, a piece of ceramic in shape of a ring had been used to reinforce this area. Removing it to re-align the two parts would likely damage the original and seemed an unnecessary step for its display.


The treatment then focused on the large frontal discoloured repair. Its likely size was palpable from the inside but its limits on the front were unknown. Slowly I started removing discoloured paint and whitish filling residues sitting on the terracotta surface and later used a chisel to remove it entirely. This successfully removed the top, softer fill, but under this, a cement-type large fill was found, securely attached to the terracotta, result of the previous intervention. I decided to maintain it and work around it as to not damage the ceramic surrounding it.


Surface cleaning tests revealed that a combination of a low concentration deionised water solution of a non-ionic surfactant, in combination with steam cleaning was enough to remove dirt and staining from the intricate surface patterns.


To ensure that the cement would not impact on the fillers I would then apply onto it, its surface and all terracotta break edges were sealed with a conservation-grade acrylic consolidant.


I chose plaster as the main filling material for this large area as to give stability to the whole piece. This would not be adequate for the last layer since a softer, slow-drying filler was needed to replicate the stamp decoration later.

The fill was made in a way that allowed for its removal before securing it in place. This step was important to minimise the amount of water being absorbed into the terracotta. Excess trapped water could have impacted on the drying of the subsequent materials as well as driving the propagation of mould or other organic matter.


This was followed by the application of a layer of nylon-reinforced, air-drying modelling clay needed for the reproduction of the impressed decoration. I used stamps made of wax and silicone taken from the original to replicate the patterns.


All fills were retouched with acrylic paint to match the terracotta tone, sympathetically. The large plaster fill is left bare inside for easy recognition when handling the bust.

Buttons and vine leaves’ elements were individually copied, attached and retouched to match. They were applied after discussions with the Museum on whether a less decorated fill would be enough.

I also filled the break-line at the neck and retouched accordingly since the aim was to reconstruct losses of material, rather than making a smooth, false-looking joint. Where there is misalignment, the discrepancy is acknowledged.


Above, before and after conservation.


© 2015-2020 by Tiago Oliveira