A method and apparatus for closing a vascular wound includes an apparatus that can be threaded over a guidewire into place at or adjacent the wound. The apparatus includes a chamber that encloses a hemostatic material therein. When the apparatus is positioned adjacent the wound as desired, the hemostatic material is deployed from the chamber. A blocking member distal of the hemostatic material functions as a barrier to prevent the hemostatic material from entering the wound. Blood contacts the hemostatic material, and blood clotting preferably is facilitated by a hemostatic agent within the material. Thus, the vascular puncture wound is sealed by blood clot formation.