Insert a syringe needle into the bulged area and release the trapped air.
Evenly inject AB glue or silicone into the hollow layer.
Remove the needle and gently press the surface until the glue or silicone solidifies.
Insert a syringe needle into the bulged area and release the trapped air.
Evenly inject AB glue or silicone into the hollow layer.
Remove the needle and gently press the surface until the glue or silicone solidifies.