Friday 13 September 2013 by Jocelyn Evans. 1 comment
First World War Centenary, Conservation, News, Dioramas

While Kasi has been working away at those pesky crates, I’ve been tasked with adhering the flaking paint on the painted backdrops.  In conservation we call this process ‘consolidation’.  While the backdrops of the large dioramas are all in pretty good shape, the two small diorama series (‘Transportation of Supplies’ and ‘Evacuation of the wounded’, each comprising 9 scenes) have not been so lucky.  On some of these small scenes (painted by artist Louis McCubbin) the bonding between the paint film and the curved plaster domes has failed in certain areas, and over time this has resulted in the paint lifting and flaking away from the surface, and even falling off.  The images below show flaking paint on backdrop number 6 from the Transportation series (Within the sound of the guns). For these photos I’ve lit the dome with a strong raking light, so that I could see the flaking very easily. 




 'Transportation of supplies, Palestine, 1916: Within the sound of the guns (6 of 9)'.  Flaking paint on the backdrop.

With my background in paintings conservation, adhering flaky paint is a run-of-the-mill task, or so I thought.  But I’ve quickly found out there’s a big difference in working on a painting in the conservation studio as opposed to lying on your back or stomach in an awkward position and trying to do the same task!  Not to mention fighting gravity; in the studio you can put an artwork flat, so the loose pieces can’t drop off while you wait for your adhesive to set.


Not my most flattering angle!  Activating the adhesive and smoothing the paint down with a heated spatula.

Consolidating loose paint is usually a two-step process.  First you need to get the adhesive into the cracks and under the paint flakes.  Next you need to make sure that the paint will lie flat in the right position as the adhesive sets.      After some trials with different materials, I chose to use an adhesive called Beva 371, which is a heat-set adhesive.  Although you apply it as a liquid, it isn’t really that sticky until you heat it to its activation temperature, and then it will hold anything down! It has better flow when it’s warm, so I brushed or syringed warm liquid Beva 371 under loose flakes and into raised cracks.

The video below shows the second step. 

After leaving the adhesive for at least 24 hours to dry, I gently heat the area to the activation temperature of the Beva 371, then ease the raised paint back into plane, holding it down until it sets.    I’m using a hot-air pen to heat the area, which has a controllable heat and air speed, so I can tailor it to exactly the right settings for the job.  Beva 371 was developed for paintings conservation, and its activation temperature was designed to coincide with the temperature at which a regular oil paint film will begin to soften.  This helps me ease the flaky paint back down flat at the same temperature that the adhesive will grip it.