Stabilisation and presentation of a detached wall painting after an earthquake by Colombian artist Lucy Tejada

Introduction: Wall paintings are complex, multi-layered systems that should ideally be preserved in situ. Detachment and transfer of wall paintings are drastic, irreversible interventions that severely impact their physical structure and aesthetic value. In 1999, an earthquake in Pereira, Colombia, damaged an 8 x 2.9 meter wall painting titled "Guaca Pobre, Guaca Rica" (Poor Tomb, Rich Tomb) by Lucy Tejada, dated 1962. The building housing it was scheduled for demolition, necessitating the painting's detachment and temporary storage from 2004 to 2007. These interventions were commissioned to Rodolfo Vallín. The detachment caused severe damage and adhesion issues between plaster layers. A new support was constructed using an iron lattice, metallic frame, and expansive polyurethane foam, which were incompatible with the original lime-based plasters. When mounted in a new building in 2007, the inadequate support led to cracks and adhesion problems. Extensive repainting was done to conceal the damage, covering large areas of the original painting. To address these issues, stabilization with a custom-mixed injection grout was proposed. This intervention involved introducing a compatible adhesive material with bulking properties to re-adhere the different layers of both original and added materials. This poster discusses the intervention undertaken between 2016-2019 by Proyecto Patrimonio, a Colombian non-profit organization dedicated to cultural heritage conservation. The objectives were to: enhance the support system of the detached wall painting; stabilize the painting by solving adhesion problems through custom-mixed injection grouting; improve the aesthetic presentation of the wall painting. The intervention aimed to address several complex issues arising from the painting's detachment, as severe damage and lack of adhesion between plaster layers occurred; incompatibility between original lime-based plasters and new synthetic materials; inadequate support leading to cracks and adhesion problems; extensive repainting covering large areas of the original painting. By focusing on enhancing the support system, solving adhesion problems, and improving aesthetic presentation, the intervention sought to stabilize and preserve this important wall painting by Lucy Tejada. The Wall Painting: Technique and Problems: "Guaca Pobre, Guaca Rica" was originally placed at ground level in the Republic Bank's Cultural Headquarters in Pereira. The primary support was a brick wall with a concrete column on one side. The artist applied two lime-based plaster layers (intonaco and arriccio) in sections (giornate), with some details added in secco technique using organic binding media. In 2004, despite known adhesion issues between plaster layers and the primary support, the painting was detached without prior grouting or stabilisation. The detachment process involved applying a synthetic organic resin coating, adhering a temporary lining, covering it with a gypsum-Styrofoam mixture for protection, and then removing this mixture before storage. The painting was cut into two pieces where it met the concrete column. Contrary to the detachment report, exploratory windows revealed that no brick wall remained; instead, the painting was layered over open-weave fabric adhered to expansive polyurethane on a metallic lattice as its new primary support. The two pieces were mounted independently in metal frames that were insufficient for proper support. Detachment led to deformation and cracking throughout the painting. This damage was concealed with fills and extensive repainting after three years in storage when it was mounted in a new building at an altered height of 75 cm above ground level. Within a decade, new problems emerged: cracks along the bottom of the painting; deteriorated corners; colour alteration of repainting. A 2016 inspection revealed that over 50% of the painting had detached from its foam support, with repainting covering 43% of the mural area. This case highlights several issues in wall painting conservation: 1. Importance of addressing existing problems before detachment. 2. Risks associated with cutting and remounting large paintings. 3. Need for adequate support structures in new installations. 4. Long-term consequences of extensive repainting and use of incompatible materials. 5. Impact of altering original positioning of site-specific artworks. The challenges faced in preserving "Guaca Pobre, Guaca Rica" demonstrate complexities involved in detaching and relocating wall paintings. Reinforcement of frame and support: Since dismounting the painting was nearly impossible due to its mounting on a metal frame fixed to the concrete wall, conservation work was conducted in situ. The first step was reinforcing the mounting system with engineers collaborating on improvements to the metal frame by constructing a new steel base that supports its bottom part. This includes a neoprene layer that avoids direct contact with the frame while providing flexibility during seismic movement. New anchoring points were welded to secure it further to the concrete wall. The gypsum fill between the metal frame and detached wall painting needed replacement as it did not adequately support weight. This involved removing segments of gypsum fill and replacing them with lime-based mortar containing quartz sand. Once replaced and set for 20 days, holes were drilled into this fill every 5 cm for steel rods inserted into it and adhered to the frame with epoxy Red Head G5 for complete support. Materials testing for conservation: the selection of grout materials depends on desired working properties and performance characteristics over time. For this project, grout needed to address adhesion issues between various layers while being lightweight enough not to stress the support system. Key requirements included: Sufficient fluidity for application through small needles; good bulking properties; ability to set in low carbon dioxide environments; low shrinkage; good cohesion and adhesion; good injectability. The chosen binder was lime combined with glass bubbles K46 and pumice as fillers; pozzolan enhanced strength through lime-pozzolan reactions. Three adhesives/additives were tested: albumin, hydroxyethyl methyl cellulose (HEMC), and polyvinyl acetate (PVA). Nine grout mixtures were tested in Bogotá through fluidity trials, shrinkage tests, and wet density measurements: PVA and methyl cellulose grouts were discarded due to long drying times; high concentrations of beaten albumin improved porosity by reducing density; increasing glass micro-spheres improved contraction resistance; replacing water with soda reduced density further. The best-performing grout composition was one part lime mixed with three parts glass bubbles K46, one part pumice, plus 0.5 parts albumin whisked in soda. Injection Grouting: Injection used small needles for access points through existing cracks or small holes when necessary; these were filled afterward with lime-based mortar. This process emphasizes developing conservation solutions for detached wall paintings through extensive testing and adaptations on-site. Presentation: The mural's extensive repainting necessitated partial removal of repainted areas that covered original artwork—revealing brush strokes altered by previous restoration efforts using acrylics that mismatched original colours. Ethanol effectively removed repainting with minimal mechanical action revealing small abrasions but uncovering much of the original work underneath. A water-based acrylic varnish evened out surface gloss before retouching using compatible materials like acrylics or soft pastels. Conclusions: 1. Irreversible damage: The detachment caused significant damage including cracks and loss of original paint due to unaddressed pre-existing adhesion issues. 2. Structural reinforcement: Post-detachment frame reinforcement included installing a new metal support with neoprene while replacing gypsum fill with lime-based repair for adequate structural support. 3. Material incompatibility: Previous detachment processes used materials incompatible with original supports like varnish or polyurethane. 4. Grout development: A custom grout was developed using compatible materials creating light yet strong adhesive properties. 5. Repainting removal: Large areas of repainted surfaces were removed revealing original artwork underneath. 6. Artistic integrity: New mounting height altered artist's original intention affecting not only the way it altered the architecture around it and how it fit and compliment it, but its classification as a true wall painting due to isolation from its intended context and new mounting. 7. Overall improvements: Interventions enhanced structural stability while improving aesthetic presentation allowing better appreciation of Lucy Tejada's work. In summary, while conservation efforts addressed many issues improving stability and appearance significantly, irreversible changes from initial detachment remain evident highlighting complexities in conserving wall paintings effectively.