Do it Plumber's Putty 7 Oz.

Long-lasting and flexible. Will not support bacteria or harden, shrink, crack, or crumble even if can is left open. For setting bowls, rims, strainers, faucets, etc. Do not use on marble, synthetic marble, other porous surfaces or on plastic lavatories and fixtures. Meets Federal Specification TT-P-1536A.