The Science of Saving Art

Unveiling the Secrets of BEVA® 371 Conservation Adhesive

Art Conservation Materials Science Cultural Heritage

The Invisible Guardian of Cultural Heritage

Imagine a world where Van Gogh's starry nights slowly crumble into oblivion or where Renaissance masterpieces peel away into dust. This was the frightening reality before modern conservation science developed advanced materials to protect and preserve our artistic heritage. Among these materials, one adhesive stands out for its revolutionary impact: BEVA® 371.

Developed in the 1970s by Gustav Berger, this remarkable conservation adhesive has become an indispensable tool for conservators worldwide, protecting countless paintings and cultural artifacts from the ravages of time 1 .

What makes this synthetic adhesive so special? How has it evolved to meet changing conservation needs? And what does scientific testing reveal about its ability to preserve paintings for future generations? This article delves into the fascinating science behind BEVA® 371, exploring its composition, reformulation, and performance as a consolidant for painted surfaces.

The Evolution of BEVA® 371: From Revolutionary Invention to Modern Workhorse

BEVA® 371 emerged from Gustav Berger's systematic research program in 1967 that sought to improve upon traditional wax-resin combinations used in painting conservation. Berger methodically developed and tested numerous formulations composed of ethylene vinyl acetate (EVA) resins combined with various waxes and ketone resins 1 .

1967

Gustav Berger begins systematic research to improve wax-resin conservation adhesives 1 .

1970s

Original BEVA® 371 formulation is developed and gains widespread adoption in conservation practice 1 .

Late 1970s

BEVA® 371 film is developed, expanding application possibilities for fragile materials 1 .

2020s

Comprehensive reassessment leads to development of BEVA 371 Akron Formula scheduled for implementation by June 2025 2 .

The winning formulation—BEVA® 371—consisted of a sophisticated blend of polymers and additives that created a balanced system providing both strength and appropriate softening characteristics 1 . Following the success of the original solution form, Berger developed BEVA® 371 film in the late 1970s, expanding application possibilities for fragile textiles and paper where impregnation or staining needed to be avoided 1 .

Behind the Formulation: The Chemistry of a Conservation Marvel

Core Components
  • Ethylene Vinyl Acetate (EVA) Copolymers Backbone
  • Ketone Resin (Laropal K80) Tackiness
  • Cellolyn 21 Plasticizer
  • Paraffin Wax Penetration Control
Reformulation Drivers
  1. Aging Stability concerns 5
  2. Solvent health and safety issues 2
  3. Batch consistency challenges 5
  4. pH compatibility questions 1

BEVA® 371 represents a sophisticated polymer engineering achievement specifically designed for conservation needs. Each component plays a crucial role in the adhesive's performance, creating a system that provides both structural strength and flexibility essential for preserving delicate artworks 1 .

The reformulation effort aimed to address several concerns that had emerged over decades of use, including aging stability, solvent composition, batch consistency, and pH compatibility with various substrates 1 2 5 .

Putting BEVA® 371 to the Test: Scientific Assessment of Performance

Conservation scientists have developed sophisticated testing protocols to evaluate BEVA® 371's performance as a consolidant for painted surfaces. These assessments go beyond simple adhesion tests to examine multiple factors critical to conservation practice 3 5 .

Testing Methodology
  • Mechanical Properties assessment 3 5
  • Response to Environmental Changes 3
  • Aging Behavior studies 5
  • Reversibility testing 5
  • Visual Impact evaluation 3
Key Findings
  • Significant strengthening of degraded canvases 3
  • Rapid and reversible response to RH changes 3
  • Good aging stability over time 5
  • Appropriate reversibility characteristics 5
  • No discernible color change 3

Mechanical Properties Comparison

Consolidant Type Young's Modulus at 20% RH (MPa) Young's Modulus at 80% RH (MPa) Reduction in Stiffness
Untreated Canvas 128.4 ± 6.7 87.5 ± 4.3 31.9%
BEVA® 371 145.2 ± 7.2 98.3 ± 4.9 32.3%
Animal Glue 139.7 ± 6.9 92.6 ± 4.6 33.7%
Nanocellulose (CNF) 162.8 ± 8.1 112.4 ± 5.6 31.0%

Source: Heritage Science volume 8, Article number: 52 (2020) 3

The Art and Science of Application: BEVA® 371 in Practice

Solution Application

Traditional method involving preparation with solvents, application with a paint roller, and activation with heat 2 .

Film Application

Film version offers simplified handling and controlled thickness, cut to size and activated with heat and pressure 1 .

Localized Consolidation

For small areas of damage, using specialized tools like heated spatulas for precise application 6 .

Conservation Applications

Paint Consolidation

Effectively stabilizes lifting, flaking, or powdery paint layers by penetrating cracks and creating bridges between detached particles and the substrate 6 .

Lining Applications

Remains one of the most popular adhesives for lining paintings—attaching a new canvas support to the back of a weakened original canvas 7 .

Diverse Material Compatibility

Applications beyond paintings, including textile conservation, leather repairs, and paper conservation 1 .

Versatile Formats

Available in both solution and film forms to accommodate different conservation needs and application preferences 1 2 .

The Future of BEVA® 371 and Conservation Adhesives

As conservation science advances, BEVA® 371 continues to evolve alongside new materials and methodologies. Recent research has explored several promising directions that may shape the future of art conservation adhesives.

Water-Based Alternatives

Concerns about solvent exposure have motivated research into water-based alternatives. Interestingly, one study investigated EVA water-based resins applied as foamed adhesives, finding promising results for lining applications without the need for heat activation 7 .

Nanocellulose Innovations

Comparative studies have shown that nanofibrillated cellulose (CNF) can provide even higher stiffness values than BEVA® 371, suggesting potential for future developments in conservation materials 3 .

Improved Formulations

Ongoing reformulation efforts aim to enhance BEVA® 371's aging stability while maintaining its valuable working properties. The BEVA 371 Akron Formula scheduled for implementation by June 2025 represents the latest evolution in this process 2 5 .

Application Techniques

Researchers continue to refine application methods to maximize performance while minimizing potential risks to artworks. This includes developing specialized tools and protocols for different conservation scenarios 6 .

The ongoing development and assessment of conservation materials like BEVA® 371 embody our society's commitment to preserving cultural heritage for generations yet unborn. Behind each tube of adhesive lies a profound recognition that art connects us across time and space—and that science provides essential tools for maintaining these precious connections.

References