Foam underlayment is used for many interior decorating or craft projects because of its flexibility in creating different shapes. Some projects, such as making window cornices, require the foam to be glued together in order to form the shape desired. The easiest way to glue foam together is using a spray adhesive, so select an area with good ventilation for your project. Spray adhesive can be purchased at a craft or home improvement store.
Cover the surface you will use for the task with a plastic drop cloth.
Spray adhesive glue to both pieces of foam. Allow the foam to sit 10 to 15 seconds so that the adhesive becomes tacky.
Place the glued area of the two pieces together in the shape you wish to form. Press the foam firmly together once the pieces are properly placed. Hold the foam in place for several seconds, allowing the glue to take hold.
Wait 10 minutes for the glue to dry. If needed, tie fabric strips or ribbon around the foam to hold it in place while drying.
When gluing multiple pieces of foam together, allow each glued section to dry completely before gluing the next piece to the set.
Wear gloves and a mask when spraying the adhesive.