Abstract: This invention relates to the art of machine repair. The present invention relates to an expandable, automated, welding device and methods used to build up material on the inner surface of a bore so that the bore can be restored to original working order. More particularly, the invention relates to the welding and repair of bearing or bore surfaces. The present invention is designed to allow easy setup and use through means of easy adjustment of the apparatus through manual adjustment of the significant positioning parameters, simple linear controls to adjust process parameters of the buildup process, and, relatively small in size. Moreover, the device allows for easy expansion of the welding torch allowing for a very broad range of engagement sizes. The present invention has a compressed air cooling means to prevent operation failure under high temperature conditions. Furthermore, a non-conductive coating has been applied to the welding torch making it less prone to damage, and safer to operate.