Surface InsensitiveSome surfaces are harder to bond than others. Chances are that 95% of your product is made out of those surfaces, and you don't need to bond anything to the other 5%. That's where Adhesive R&D's SI line-up goes to work. Normal cyanoacrylates cure in a neutral PH environment. Some surfaces, like certain types of wood, are acidic or base in nature, and will prevent a regular cyanoacrylate from curing. Not so with the super-charged SI products.