BEVA 371® Akron This is an adhesive formulated with the specific needs of professional art conservators in mind.
It is currently the most widely used adhesive for painting lining in the world, created by the prominent conservator Gustav Berger.
The Akron version is the result of a 2021 research project, supported by the Getty Foundation.
Thanks to the cooperation of international institutes, including the University of Akron, the formula was optimised so,
to lower the activation temperature of the adhesive to 55°C.This makes the product ideal for working with heat-sensitive objects, such as modern acrylic paintings.
- Low activation temperature: The adhesive works at a temperature of just 55∘C, which minimises the risk of thermal damage to the object.
- Versatility: Excellent for lining (also cold as a "spiderweb" technique), consolidation of paint layers, and facing.
- Fully reversible: Can be removed using heat or a wide range of solvents, including white spirit.
- Material safety: Composition based on ethylene-vinyl acetate copolymer, paraffinic hydrocarbons and hydrogenated rosin ester.
- Professional quality: Product intended exclusively for professional use.
- Lining: Standard adhesive for joining new canvas to the original, preferably using a vacuum hot table.
- Consolidation: Re-adhering delaminations and blisters of the paint layer (also via injection).
- Facing: Securing the picture surface with Japanese tissue.
- Fixing paint flakes: Precise reattachment of minor chips.
Composition of BEVA 371® Akron It has been carefully developed to ensure the optimum balance between adhesion, flexibility and the safety of the conserved object.
In 40%, this formulation consists of solid components dissolved in a mixture of aromatic and aliphatic hydrocarbons.
Base polymers (EVA copolymers) - The adhesive is based on two types of ethylene-vinyl acetate copolymer with different thermal properties:
- Ethylene-vinyl acetate copolymer with a Tg of 63 °C: provides flexibility and adequate bond strength at room temperatures.
- Ethylene-vinyl acetate copolymer with a Tg of 92∘C: it influences the structural stability of the joint and modifies the softening temperature of the entire mixture.
The ingredients include
paraffin hydrocarbons with a glass transition temperature ($T_g$) of 63$^\circ$C. They act as plasticisers and viscosity modifiers, influencing the application characteristics of the hot-melt adhesive.
Modifying resins - a key element of the new „Akron” formula is the change in the type of resin, which was necessitated by the withdrawal from the market of certain components used in older versions:
- Hydrogenated rosin ester: this ingredient has replaced previously used resins such as Laropal A81 and Cellolyn. This resin is responsible for the viscosity of the adhesive and its ability to wet surfaces, which is crucial for achieving good adhesion at lower temperatures.
Solvent system
Solid particles are suspended in a hydrocarbon solution. This mixture allows a liquid, transparent consistency to be achieved upon heating in a water bath.
The selection of solvents also enables further dilution of the product to adjust the viscosity for a specific task, such as consolidation or spraying. It is recommended to use DILUENT 372 or other hydrocarbon solvents in ratios ranging from 1:1 to 1:6, depending on the application method.
AppBrush, short-pile roller or spray (flocking technique using cyclohexane).
Operating temperature: During relining, it is recommended to reach a temperature of approx. 60∘C. Important: Temperatures of 70−80∘C should not be exceeded in order to avoid excessive liquefaction of the adhesive and chromatic changes in the painting.
Important advice: Always use silicone release paper during pressing and consolidation – the adhesive sticks to almost every surface, including iron soles (even Teflon ones). The adhesive should be heated in a water bath, away from open flames.
The binder is characterised by reversibility, chemical stability and excellent flexibility, which guarantees safe and long-lasting conservation effects.
Capacity: 1 litre
