Abstract: A method for producing a tubular length of material which can line the interior of a bore comprising providing a magazine having a substantial length of tubular material radially wound on itself in a number of overlapping layers, pulling one end of the tubular material from the magazine and closing this end to form a tubular cavity within the portion of the tubular material pulled from the magazine. The magazine or the closed end of the tubular cavity can be supported at the bottom of the bore and a pressure medium can be supplied to the cavity to unwind the material from the magazine while permitting relative movement between the magazine and the end of the tubular material. After the bore has been lined with the material, a substance can be supplied therein which will effectively sealed from the bore by the tubular material. The magazine can be mounted on a hollow guide which serves both to supply the pressure medium to the cavity and to introduce the substance into the lined bore.