Hargreaves Foundry were involved in Manchester Council's project to reproduce 18 impressive cast iron urns and help restore an original drinking fountain. This was just part of a £5.5 million restoration of the Alexandra Park in south Manchester.
Manchester Council employed restoration consultants who provided us with an accurate drawing based on early photographs for the urn and photographs plus samples of broken castings for the fountain. From this information we were able to make new patterns.
The pattern for the urn commenced with creating and actual size profile on plywood from the drawings. This showed the internal and external shapes of the urn and, therefore, the metal thickness.
A wooden model for the core was made that reproduced precisely the internal size and shape of the urn.
So, the process then moved onto moulding. A mould was made using the pattern (with wooden strips added) and ramming sand around this. The sand has resin added that allows it to slowly set hard. When the pattern was lifted out of the sand it left a cavity representing the outside shape of the urn.
Next a sand core was made by ramming sand into the core box (based on the model before the wooden strips were added for metal thickness). The sand core follows the internal shape of the casting and fits inside the mould.
The difference in size was created by the wooden strips that were added, the gap that then remains between the internal and external shapes in the sand is where the metal flows, creating a finished urn.
The surface of the mould is coated with a refractory paint to protect it when the iron is poured in at 1,400 °c. The mould is then left to cool for about 24 hours after which it is broken out to reveal the casting.
All the sand can then go to be recycled and re-used for new moulds, and the casting is ready for fettling. Fettling is a foundry process that involves shot blasting any sand residue left from the mould off the casting and grinding off any extraneous metal, joint lines etc.
Any waste or excess iron is then recycled and re-used for future castings.
As part of the same project we also had to restore a Victorian drinking fountain, parts of which were badly damaged and other parts which had completely disappeared. This kind of restoration work provides a different kind of challenge from making castings from drawings, as with the urns.
We worked in close partnership with the restoration consultants employed by Manchester Council. We needed to take photographs, measurements and damaged sections of the original, and then set about manufacturing the missing or damaged components. Fortunately for us there is an identical fountain at St Pancras Old Church in London which helped us enormously with the detective work.
The restoration work fell into two parts; components for which we had originals, albeit damaged or broken, and components for which we only had photographs and nothing else. Where there were originals we could use them as reference to make new patterns. Where the originals no longer existed, we had to study the photographs, take measurements from the fountains in Manchester and St Pancras, scale the images and have new 'originals' made. From the new originals we were then able to make patterns ready for casting.