GB852048A - - Google Patents

Abstract

852,048. Pipe &c. coverings. HOPKINS, J. R., and McNULTY, F. E. Feb. 8, 1958, No. 4193/58. Class 99(2). In a method of cold bonding a protective wrapping to the external surface of a metallic body such as a pipe or cable without the application of any heat, wherein the wrapping comprises a cold preformed sheet of reinforcing fabric, e.g. glass fibre cloth saturated and coated on both sides with substantial amounts of highmelting-point coal tar, asphalt or microcrystalline wax, the sheet being of at least a size to be wrapped about the body, a cold, heavy-bodied, grease-like, solvent-release, bituminous primer is first applied to the surface of the body and the sheet is wrapped tightly around the body and over the cold primer while the latter is still wet. The primer includes a residue constituent of asphalt or coal tar and a solvent both of which are chemically compatible with the coal tar, asphalt or wax, the solvent being absorbed by and dissipated out of the sheet to cause the sheet to become solidified and bonded to the body with the sheet and primer residue forming a homogenous wrapping. As shown, the sheet 2 is wrapped convolutely around a pipe 5 to provide a longitudinal lapping 8, additional primer 6 being applied to the lapping ; alternatively, the sheet is wound helically or spirally about the pipe, adjacent convolutions of the sheet overlapping by half the width of the sheet. A second coating of cold primer 6 and a second wrapping may be applied.