The first thing I started with was making moulds from cuttle fish. At first this was done by pressing objects into the cuttle fish and then I moved on to making shapes on the laser cutter. The cuttle fish works well for making moulds because it is relatively soft so making impressions is easy and it gives the mould a very good surface finish.
This image shows the two halves of a cuttle fish mould. The mould is prepared by sanding the soft side until it is flat and sits flush with it's pair. You may need to trim the edges on the band-saw so that they are the same size.
You can now make the impression. Press your shape in with your fingers, starting with the edge and work into the middle on of the model until you get it to the depth you require. Depending on the size of you cuttle fish and your model you might be able to make two impressions on the same piece. However to make sure the molten metal does not get stuck near the top of one cavity and not make it into the second you should add extra channels as shown in the picture. These can be removed easily later. Last thing to be done is to make a funnel shaped opening at the top of the mould for filtering the molten pewter in the the cavities and clamp the two pieces together.The cuttle fish is very brittle. The image above shows the remains of cuttle fish that broke whilst pressing a model in.
Once the mould is ready and clamped together you can start to melt the pewter. It has a relatively low melting point so it can be done in a metal pot on a camping hob. It will take about 10mins to melt the pewter, and once it has you can pour it directly into the mould. It will need about 5mins to cool but it will set within a minute.
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