Water Damage


Water Damaged Oil Paintings are a common problem

The first consideration addressing water damage to a painting is to consolidate the affected areas to prevent any further deterioration.

Certain types of water damage soon become visibly apparent. Typically, the paint will bubble, blister and flake. There may also be a covering of fine white powder or mould around the affected area.

Below left shows the damage if left untreated. Below right is a typical example of a badly stored painting. This William Orpen portrait was discovered standing upside down in a damp cellar. This is evident by the water damage at the top of the painting and 'blooming' caused by the mildew.

          

Water Damaged Oil Paintings - Considerations

The surface of some paintings may initially only seem to distort into a buckle or tube shape. However, without immediate attention the 'reaction' of the water to the fabric of the painting will continue to deteriorate and de-laminate the paint from the canvas.

The damage in the example below only appears to be limited - Oil and water are antipathetic, and any prolonged proximity of the two usually spells trouble!

A recent water damaged painting before significant deterioration set in

See how water gravitates towards the lower part of the canvas and begins the process of seperation

The exact extent of the water contact with the picture will usually be more evident as a lighter coloured water stain apparent on the reverse of the canvas. The back of the canvas [verso] is the Achilles heel of the painting!

Originally when the canvas was made, the raw linen would have been glue sized, before being applied with a preparation primer. Basically, water penetration will attack the starch in the size, causing it to swell and blister. As the canvas dries, it shrinks, causing localised distortion. Although the canvas may appear to dry out, the breakdown of the starch will have created a weakness that will enable moisture from the general atmosphere to gradually penetrate, and consequently cause the onset of mildew. Inevitably rot will set in, and result in a separation between the primer and the oil paint itself. The paint then becomes unstable, flakes, and breaks from the surface.

The only remedy to prevent this inevitable deterioration is to reline the painting. The process would first involve placing the original painting on a vacuum steam press, which will help rebalance the basic chemistry of the original ageing canvas, before sealing it. It is then heat bonded to another canvas to strengthen the overall surface.

Boards and panels made from timber tend to be less porous or absorbent than canvas, but basically the same principles described above, apply.