Stage 1 - Structural treatment

Structural treatment

When treating a damaged artwork, the first task is to stabilise the structure of the work to prevent further damage. The Sirens and Ulysses was extensively damaged, leaving both the supporting canvas and the paint layer extremely fragile. Conservation work had been done in the early 1900s but this had deteriorated too. First we had to remove these old materials; then we could begin the essential structural work.

The back of the canvas

1. Removing the old lining canvas

The painting, which had been faced in the 1980s, is placed face down onto a smooth flat surface. The old degraded lining canvas is peeled away from the original canvas slowly and gently in thin strips.

2. Removing the animal glue

The hard, powdery composition glue is scraped from the original canvas using the rounded edge of a scalpel blade. The glue is removed in a 'checkerboard' pattern of alternating squares to allow the original canvas to relax evenly. Any remaining tough glue is softened using a poultice, then removed using the scalpel.

3. Repairing tears and filling holes

Removing the glue reveals many tears and holes in the original canvas. These are repaired using PVA glue to join the tear edges, and by inserting new pieces of canvas into the larger holes.

Turning the painting

4. Making a vacuum envelope

The paint layer has to be stabilised before the painting can be re-lined. To do this the painting needs to be turned. To turn the painting, first an envelope of plastic (Melinex) is placed onto a wooden frame around the painting. Air is sucked from the envelope, creating a taut 'drum skin' with the painting inside.

5. Turning the painting over

With the vacuum pressure on, the painting becomes stiff and can be lifted and turned over without fear of damage. The Sirens are revealed for the first time in two years.

The front of the painting

6. Removing the facing

The 1980s protective facing tissue is removed slowly by slightly moistening the tissue paper and gently peeling it away from the paint layer.

7. Consolidating the paint layers

Parts of the paint layer have come loose from the original canvas and have to be glued back down. Isinglass adhesive is fed beneath the paint flakes using a small brush. The glue is then set using a heated tool.

8. Removing old restoration

The paint layer is still partly hidden by old restoration work and discoloured retouching paint. These materials are removed by softening them with solvents and scalpel scraping.

Lining the painting

9. Preparing the new lining canvases

Lining gives structural strength to a weakened canvas and reduces tension through the layers of a painting. Two lining canvases are prepared, one of linen and one of cotton canvas that is used as an interleaf.

10. Stretching, applying the glue, sandwiching two layers

Each canvas is stretched and decrimped, then coated with layers of BEVA adhesive, a modern synthetic adhesive that is both stable and reversible. Both canvases are heated under vacuum pressure to seal them together.

11. Lining the painting with the new canvas

The painting is placed inside the vacuum envelope with the two lining canvases and heated on a hot table under vacuum pressure. The lined painting is allowed to cool before the pressure is released.

12. Transferring the canvas to the roller

The painting is re-faced using tissue and a wax-resin adhesive to protect it during transport. It is then rolled carefully onto a wide cardboard tube and secured, before wrapping it in polythene bubble wrap.