USG 380051 Sheetrock® Topping Joint Compound, 4.5 Gallon PailUSG Sheetrock Brand Topping Joint Compound is a low shrinkage compound recommended for use in second and third coats over USG Sheetrock Brand Taping and All Purpose Joint Compounds. 4. 5 Gallon pail Applies quickly Provides easy workability, excellent slip and bond, and low shrinkage Can be used directly from the container Requires only minimal mixing, thinning, and retempering Unsuitable for embedding tape or for use as a first coat over metal corner