Blacking a narrow boat hull at Wigan dry dock.
2021-10-29 - 2021-11-05
The dock was flooded, the gates opened and the boat floated into position.
The dock was then drained and the boat rested onto trestles. Care had to be taken during the drain down to ensure delicate parts of the boat such as rudder, skeg and propeller were clear of the final trestle.
With the water drained, the hull was defouled using an industrial power washer. This process revealed bright metallic spots where galvanic corrosion has been taking place.
Any loose remnants of the old bitumen blacking were scraped clear using a chisel. Initially more attention was paid to the waterline which was taken back to bare metal using a grinder with abrasive pads.
After assessing the condition of the remaining coating, it was decided that all old material beneath the waterline level was to be removed back to bare metal. The texture of the old material had become so deeply furrowed that overpainting it and achieving a consistent coating thickness would have been impossible.
The chisel was used to scrape off all remaining material from the waterline down to the baseplate on the entire hull; a painstaking and physically exhausting task.
The flat metal finish was much easier to paint than attempting to overpaint the previous coating. The warmer than average temperatures for the time of year enabled us to apply three full coats of bitumen hull blacking whilst adhering strictly to the overcoat times specified by the manufacturer.
New anodes were also installed since the old ones had less than 25% remaining.
The boat was refloated on 2021-11-05.
5 ноя 2021
