An airfoil includes, among other possible things, a main body extending between a leading edge and a trailing edge. Channels are formed into the main body, with a plurality of ribs extending intermediate the channels. A cover skin is attached to the main body. The cover skin is welded to the main body with a weld at outer edges. An adhesive is placed between inner surfaces of the cover skin and the main body. The adhesive is deposited inwardly of the outer edges of the cover skin. A method of constructing an airfoil is also disclosed as is a gas turbine engine.