Gluing leather with Industrial glue

Gluing Leather? What is the best way to glue leather and what is the best leather glue? All will be revealed.

Gluing leather is a common process, particularly in applications like boot and shoe repair and repairing bags, purses etc. Although stitching leather is a rapid method of joining leather pieces, the use if glue both holds the seam together before stitching commences, and adds to the overall strength of the seam. First of all, lets look at the basics…….

Leather has two sides……..the flesh side is the back of the leather, basically the rough side. The grain side is the physically appealing side. Our technicians have put together three easy steps for the optimum bonding of leather materials. Note that this information refers to natural leather only, not synthetic leathers.

Step 1: Preparation. First of all, it is important to make sure the pieces of leather are clean and dry. It is impractical to think that any glue will stick to a surface which is not clean and dry. Depending on which side, i.e. the gain side or the flesh side, there is a slightly different procedure for each. The flesh (rough side) can be glued as is. The grain side will need to be abraded, in order to increase the grip of the glue. The best way to abrade the flesh side of the leather, is to use some P60 or P80 sandpaper.

Sand the area onto which the glue will be applied (taking care not to sand the area which will be seen after the gluing process is complete)! After the sanding process, some workers use a knife to further cut into the leather, in a criss-cross pattern. This will further increase the strength of the bond, but care must be taken, not to cut through the leather.

Step 2: Glue Application. This may be regarded as the tricky part, but if care is taken, both in the selection and application of the glue, the process should be problem free. In advance of applying the glue, you may decide to mask off the areas onto which the glue will be applied. This will protect other areas should an accident occur!! We always suggest a contact adhesive for gluing leather. A contact adhesive is an adhesive which is applied to both sides of the materials being glued.

There are two adhesives which we can suggest for gluing leather. First is S3255,  a very strong polymer glue, which has proven use in gluing leather. The ideal candidate for small to medium size pieces of leather. For larger pieces of leather, S1023 is suggested. Apply a thin coat to both sides of the leather. Allow about seven to ten minutes before applying the second coat.

Step 3: Assembly. Within fifteen minutes of the application of the last coat of glue, we should assemble the parts. Because we have used a contact adhesive, we have only one chance to do this, once the glued surfaces touch each other, pulling them apart to reposition them, will be tough to impossible!

A tip, if the parts to be glued are long, placing a piece of grease proof paper between the glued parts, and pulling it out as you go, is a great tip!!

After the pieces have been placed together, the use of a rubber roller or mallet to really push the glued parts into intimate contact with each other, is suggested. If possible, the glued seam can be clamped with bulldog clips or something similar, and left overnight. The jobs done!!

For all applications with leather, please contact our laboratories for immediate advice.