White Lightning For filling holes and cracks in most common construction surfaces, including wallboard, plaster, drywall, wood, concrete and masonry. Non-slump, silky smooth formula provides excellent filling capacity in one coat with no shrinking or cracking. Sandable and paintable in as little as 30 minutes. No rust bleed-through retains a permanent brilliant white color. Mildew resistant. Non-flammable, odorless. Easy water clean up.