We have a Corian Material Like sink that is moulded into our Corian Material countertop. The sink is white, and thus the Insinkerator Garbage Disposal Flange is white, but flaking its white color. Question: whne installing the new white flange, should I use conventional plumbers putty, or a white silicone material that I BELIEVE was used on the original installation. I have heard that one Silicone is used, a new application of silicone will not stick.. Advise Please..