I had to replace the steel keel runners on my DD27 during the winter of 1991/92. 1 bought the boat new in 1975 from Devon Craft, Salcombe. Corrosion had been obvious for several years and was clearly becoming dangerous; I was concerned they would break and pierce the bottom of the boat. The corrosion was confined to the band about one metre forward from the centreplate and those on either side of the plate. The runners on my small bilge keels, which are an extra on my boat, and at the bow and stern were undamaged. I suspect this localised corrosion, confined to where the boat lies on the bottom, is the result of the drying mooring on the deep salt mud at the top of Bosham Creek. I would expect that anaerobic conditions and sulphides are involved.

I replaced the damaged runners with type 316 (EN585) grade stainless steel which contains molybdenum and is used in chemical marine and food processing industries and has great resistance to corrosion. I was able to buy strip 2.5 cm x 0.5 cm and this served well. It was the correct width for either side of the centreplate. It cost £35 but not all was used. The job was done with the boat careened onto its side. This is easily accomplished single handed using the trailer winch and two or three turns of a thick rope round the mast below the spreaders and above my extra shrouds (see DCA Bulletin). When pulled over I shore it up under the keel and am thus able to release tension on the mast. I think this is substantially easier than removing the centreplate and inverting the entire hull as described in DY Newsletter spring 1992. I had removed the floorboards thinking to get at the nuts holding the runners on to the boat but because of the fibre glass bearers for the floor boards I could not do this, even if it had been necessary.

I was lucky to have the help of a neighbour who is a skilled steel fabricator and did boat building in his youth. We carefully removed the runners without breaking them, cutting the one forward of the centreplate into uncorroded steel with a hacksaw. They were fastened with countersunk SS screws into rubber rawlnuts as described in the DY Newsletter. All these unscrewed without difficulty, and the rawlnut rubber plugs remained in situ.

We used the removed runners as templates to define the exact length and drill the screw holes into the new SS runners, ensuring that there would be no overhang over the centreplate slot. We carefully offered up the runners and bent them slightly into shape by hammering over a wooden block. Very little shaping was required but it was clearly necessary to make sure that the runner did actually fit the curvature of the keel. The screws returned into their own holes, but patience was needed to ensure that the screw caught the thread of the rawlnut in situ and did not push it out. One rawlnut was corroded and pushed through but we were easily able to replace this with a new one. The keel was carefully cleaned down to the gel coat and the new runners bedded in with silicone mastic and so far as I am aware everything is watertight.

This was easily done by a skilful metalworker who had the requisite tools. In all (excluding careening etc.) it took about four hours. I could not have done it on my own. I am grateful to Brian Welch of Fontwell for his advice and expert workmanship.

I have an unused piece of the SS bar 269 cms in length if anybody would like it. A narrower strip would be required for the bow and bending it to the correct curvature would clearly require competent metalworking skills. I purchased this steel from CBA Metals Ltd, Daux Road, Billinghurst, Sussex RG14 9SN (0403 783944).