Page 214 - Haddonstone Gesamtkatalog 2018

USEFUL INFORMATION

THE MANUFACTURING PROCESS

Mould Making
Each Haddonstone design is made to order. If the order is for a
standard design, production can commence as soon as a colour has
been agreed. If a custom design is required then a mould needs to be
made. For a relatively simple design, such as a window sill or coping
stone, wooden moulds will be manufactured in the company’s wood
shop. One of the skilled in-house carpenters will interpret drawings to
produce a precise mould, the exact reverse of the shape ultimately

Creating a wooden master model for a new column.

required. Timber moulds have a comparatively limited life compared
to their fibreglass equivalents. However, the speed with which timber
moulds can be produced, combined with their relatively low cost,
normally makes this type of mould more economical for the client.
The production of a fibreglass, rubber-lined mould in the company’s
studio is much more time-consuming and is only undertaken if the
design is complex or if there are likely to be numerous castings. The
work is one of the most highly skilled within Haddonstone, benefiting
greatly from artistic and practical skills. Before such a mould can be
made, it is first necessary to have a model. This can come from a variety High-tonnage silos store raw materials needed to produce Haddonstone.
of sources: it could be created within the wood shop; it could have been
carved from scratch by an in-house craftsman, normally in plaster, either void now left in the centre is the precise shape and size of the finished
replicating an antique piece for a restoration project or afresh for a new design. Particular care is taken to ensure that any seam is in a position
design; it could be a pristine antique stone; or it could be a damaged where it is least noticeable. Whether wooden or fibreglass, without a
original requiring restoration. first-class mould it is impossible to create a first-class product.

Once the master model has been created, the mould-making can Manufacturing
begin, commencing with rolling clay to a set thickness and covering the
entire model. Over this a fibreglass case is formed. As this case will be For semi-dry cast Haddonstone, the principal materials are limestone,
completely inflexible, it has to be designed in such a way as to allow its white cement, sand and a small quantity of water. This produces the
later removal. For this reason, some fibreglass cases can comprise of Portland colour with other colours requiring the addition of pigment into
more than ten sections. Then the fibreglass case is opened, the model the mix. Other key ingredients include plasticisers to improve workability
extricated and all traces of clay removed. The case is then reassembled and aid compaction as well as waterproofers for durability. To ensure
around the model, there now being a void where the clay had previously complete control of the production process, every single batch of raw
been. Into that void is poured a specially developed rubber which material delivered to the Haddonstone manufactory is quality checked,
has enough fluidity to fill every cavity whilst avoiding any air bubbles, before use. The constituents of the mix are stored in high-tonnage silos
which would be seen in the finished design. After the rubber has set, adjacent to the production area, before being mixed in small quantities
the fibreglass case is, once again, opened and the model placed into via computer controlled batching equipment and taken to a workstation.
storage. When the fibreglass and rubber case is reassembled, the At this stage, the mix has the feel of damp sand or earth.

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