METHOD FOR RUSTPROOFING INSIDE SURFACE OF HOLLOW STEEL PIPE OF STEEL TOWER

PROBLEM TO BE SOLVED: To form a rustproof coating film capable of keeping excellent rustproof ability over a long period of time on the inside surface of a hollow steel pipe with excellent workability. SOLUTION: Rustproof coating consisting of an alkaline aqueous solution which contains 0.01-1.0 mol/kg ammonium ion and 0.01-1.0 mol/kg halogen ion and is based on the alkali metal silicate shown by the general formula: M2O-nSiO2(wherein M is Na, K, Li or Cs; n is 1 to 5) is applied to the white rust-developed galvanized surface of the inside surface of the hollow steel pipe by using a coating apparatus having: a working portion 100 which can be inserted freely into the hollow steel pipe; a fixing means A which is used for fixing the working portion to the inside surface of the hollow steel pipe and composed of a working rod which is housed in a cylinder 1 and is movable backward and forward and a plurality of clamping arms 2, 3 to be unfolded/folded by the backward/forward movement of the working rod; and a coating means B fit to the tip of the fixing means A for discharging the rustproof coating. COPYRIGHT: (C)2006,JPO&NCIPI