Basic Instructions for Using Beva® 371 Film for Mounting Applications
The Beva® 371 Film is a heat activated adhesive, originally developed by Gustav Berger for relining old deteriorating or tom canvases with a new structurally sound canvas. Since its development Beva® 371 Film has proven to be a very effective adhesive in many other areas of application, such as with paper, canvas, textiles, films, wood, metal, plaster, boards, to name a few.
When you receive the Beva® 371 Film you will notice that it is composed of two materials rolled together, one of which contains the Beva® 371 Film, the other of which is a release layer. The white paper is a silicone coated paper, this is the release layer. The other clear sheet is a polyester (Mylar) film, one side of which has been coated with the Beva® 371 adhesive. The side of the clear sheet facing the release paper is the side coated with Beva® 3 71. Should you separate the layers accidentally and loose track of which side is which, the side coated with Beva® 371 will feel slightly tacky (using a fingernail you can scrape way a bit of the adhesive at the edge to confirm you have identified the correct side.)
The process of working with the film is as follows:
1) With the two layers (clear Mylar and white paper) intact, cut the film to size for your application.
2) Separate the clear layer, and lay the tacky side that was towards the release paper (this is the side coated with Beva® 371) down onto the back of one of the materials to be mounted.
3) Keep the clear film and the material to which it is being applied stationary. Using an iron set at 150° F, iron the clear plastic sheet down to the material, working slowly and carefully to cover the entire surface.
4) Once it has cooled, peel away the plastic, leaving behind a layer of adhesive on the surface which has been transferred down to your material.
5) Taking the other material that you wish to mount to this one, place it on top of the adhesive you have just prepared. Again with your iron set at150°F, heat is applied, which will melt the adhesive in between the two materials, adhering them together. Should it be of concern to iron on top of this layer (be it a painting, drawing, etc) the silicone coated white paper can be used as a barrier, as nothing will stick to the smooth side of this material.
Note: The final application of heat may take longer than in the first step, as the heat must now pass through multiple layers of material to come up to temperature and activate the adhesive.
Things to Consider:
1) Although it is not necessary to coat both sides of the material with Beva® 3 71, take careful consideration as to which side it will be easier to apply to first.
2) 2) Beva® 371 is an excellent product to use for mounting large oversized works, specifically because you first apply it to one surface, and when it cools and the release liner is removed the adhesive is not tacky, which allows for slow careful placement onto the second material to which it is to be mounted, before it is ironed down into place. Should difficulty be encountered while mounting the piece, it can be reheated with an iron to melt the adhesive, separating the layers, and the process started over.
3) Make sure you are working with the film at the correct temperature. Normal dry mounting adhesives operate at 250°F so the 150°F for the Beva® 371 is actually quite low and perfectly safe for most materials. Using an iron at too low a temperature will result in insufficient adhesion of the product, while having the temperature too high will result in possible damage to all materials in contact.
Should the only iron you have at your disposal be a household iron without temperature controls, you can do the following: With a small piece of film and a piece of paper, start with the iron on the lowest possible setting, and try to adhere the film to the paper. Keep increasing the temperature of the iron until the Beva® 371 Film starts to adhere to the paper, and increase the temperature ever so slightly and make a mark on the dial so you can return to this setting in the future.
4) Check all materials that you are working with such as plastics, rubbers, encaustic paintings, etc. can handle the heat required for use with this product before use with their respective manufacturers.
5) Test the product carefully for suitability with your materials, and that you are comfortable using it before working on original artwork.