Hall Conservation Ltd

Date:07 January, 2014

Project Information

This ship weathervane has pride of place on the top of the University Park Building, Portsmouth. The building was undergoing renovations and as part of the works the University wanted to restore the weathervane to working order.

The exposed costal environment had resulted in extensive corrosion and loose components.  On inspection we found that the frame had been made of electrically welded mild steel with the masts fabricated from gas pipe, this strongly indicated that the framework had been replaced at least once. The void inside the ships hull had been filled with expanding polyurethane foam leaving a foam ‘deck’ exposed to the elements. Years of exposure to moisture and UV had degraded the foam to such an extent that it had filled with water, significantly increasing the weight of the weathervane. Pooling water had cased the worst corrosion at ‘deck’ level although the entire framework was significantly corroded and failing, only worsened by galvanic reaction at points where the copper was in contact with the iron. The exposed ironwork had corroded to such an extend that tube mast had corroded through and separated, causing at the hull to drop down and wedge onto the cast iron shaft.

The entire 3m weathervane was removed from the building to our workshop, a difficult task from 40m up a scaffold. The foam was cut out to expose the fixing points for the masts and to allow the copper sheets to be removed from the frame. All components were tagged and labeled to and carefully removed for later reassembly.

The iron frame was in such poor condition that it decided that it should be replaced with Stainless steel, made in three sections to the same design as the existing one. On inspection, the iron frame did not fit the copper hull very well. It was loose in places and additional patches of copper had been stuck on to hide the framework. The copper hull was carefully examined and templated to create a more accurate framework.

The hull was cleaned, waxed and painted internally to protect and isolate it from the stainless steel. The original drainage holes were left open and and new sheet deck installed to prevent animal nesting.