Method of insulating an exhaust device

A method is provided for providing external insulation for an exhaust gas aftertreatment or acoustic device, including the steps of (a) securing an insulating blanket around the exterior of the device, (b) securing a sheet of foil around the insulating blanket, (c) interconnecting a plurality of wires into a sleeve oriented in an axial direction by knitting or interweaving, whereby extending the sleeve in the axial direction biases the sleeve radially inwardly, (d) positioning the wire sleeve around the foil sheet, (e) welding one end of the wire sleeve to the device adjacent one end of the insulating blanket, (f) pulling the other end of the sleeve in the axial direction to bias the sleeve radially inwardly sufficiently to apply a compressive force to the insulating blanket, and (g) welding the other end of the sleeve to the device adjacent the other end of the insulating blanket.