Page 214 - Haddonstone Gesamtkatalog 2018
P. 214



                  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.


        HADD CAT Jan 18 ARTWORK 211-222.indd   214                                                                                   12/03/2018   13:59:36
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