CORROSION PROTECTIVE METHOD OF BOLT AND NUT AND CORROSION PROTECTIVE COVER

PURPOSE:To carry out a simple and secure corrosion protective treatment of fastening bolts and nuts of steel plates in the sea water. CONSTITUTION:Corrosion protective covers 4, 5 are forced to come in closely contact with the base metal 1 by a magnet ring 7 equipped at the flange 6 for jointing steel plates 1, 1 in order to fasten a couple of bolt and nut for these steel plates and coat the head 2' and the nut 2'' with a corrosion protective covers 4, 5. And a soft corrosive protective agent 17 is injected into a feed inlet hole 9 through a pass by a pump 14. The sea water in the inside is replaced to discharge it from a outlet hole 10 and to securely charge evenly the soft corrosive protective agent 17 into the periphery of the bolt and nut. Accordingly, it is not necessary to press coating like putty or brush it for corrosion protective, and the soft corrosive protective agent can be easily charged in the periphery of the bolt and nut via the corrosive protective cover. And further, after the soft corrosive protective agent is cured, it is removed to repeatedly reuse. And moreover, construction period can be reduced, working accuracy can be increased, and the cost can be reduced.