Kitchen & Bath Stain Block? Sealant is an interior/exterior culk that has excellent bonding strength to a variety of substrates.It seals like caulk but sticks like an adhesive when fully cured while it remains permanently fleible and will not crack or discolor.This advanced sealant can be painted with latex and oil based paints and cleans up with water.The cured bead is mold mildew resistant.