Fast melting of pure solid hcp and fcc 4He at pressures between 240 and 1700 bar was studied. It was found that under these conditions solid helium exhibits properties which are quite different from those observed under near equilibrium conditions. For melting rates exceeding a certain value, and under constant volume conditions competition between surface and bulk melting was observed. Melting under these conditions starts as surface melting. During the last stage of melting a wetting transition takes place, during which the contact angle between the helium solid and the substrate (Vespel SP-1) changes from 0° to between 60 and 90°. The wetting transition is followed by continuous melting throughout the solid. The most likely mechanism of continuous melting is a disordering process i.e., the spontaneous generation of high concentrations of thermal vacancies.