Method of making a plastic article

A method of making a plastic hand grip on a steel rod having an internal conduit in said hand grip for an electrical wire between a first site on said hand grip and a second site on said hand grip comprising the steps of:

• forming a mold cavity in the shape of said hand grip around a portion of said steel rod including a surface area segment of said mold cavity cooperating with a surface on said rod in defining a passage between a first site in said mold cavity corresponding to said first site on said hand grip and a second site in said mold cavity corresponding to said second site on said hand grip,
• forming an orifice between said mold cavity at said second site therein and an overflow receiver,
• injecting into said mold cavity liquid plastic at a temperature above the temperature of said surface area segment of said mold cavity and of said surface on said rod so that said liquid plastic is quenched by said surface area segment of said mold cavity and said surface on said rod to form a tubular wall in said passage in said mold cavity having liquid plastic therein,
• injecting gas into said mold cavity at said first site therein to induce a pressure gradient across said orifice between said mold cavity and said overflow receiver so that liquid plastic is expelled from said mold cavity through said orifice and an elongated gas-filled void expands longitudinally in said tubular wall to substantially said length thereof and forms a smooth surface on said tubular wall facing said elongated gas-filled void,
• sustaining said elongated gas-filled void in said tubular wall for a time span of sufficient duration for all of said liquid plastic in said mold cavity to solidify to a self-sustaining rigidity,
• relieving said gas pressure in said elongated void and removing said steel rod with said plastic hand grip thereon from said mold cavity, and
• opening a first end and a second end of said elongated void at respective ones of said first site and said second site on said plastic hand grip to convert said elongated void to an internal conduit for said electrical wire.