27/11/2017 Blocking & Planishing
Our first day of the silversmithing module and I'm in the blocking and planishing group with the lovely Sam (finally an external teacher who doesn't treat us all like naughty children).
We're going to make a traditional lemel scoop, which is a tool for cleaning out the bench skin, so the metal filings can be sent off for recycling/refining. We started by cutting out an oval of copper sheet, using the guillotine, snips and file. The oval was then annealed to make it nice & soft. |
We marked off an arc at one end of the oval for a handle and started to block out the bowl shape.
Using the pointed end of a blocking mallet (the wooden, egg shaped one) we hit round the edge of the scoop on a sandbag. The piece had to be at an angle to the bag with some empty space behind it for the metal to “move into”. As the internal bowl shape was completed, the hitting pattern spiraled inwards to the centre (the piece was rotated rather than the mallet and it was annealed again when becoming work hardened). We also had a go with a tree stump instead of the sandbags which was much more effective as there was much less give. |
When the basic bowl shape was deep enough we moved on to planishing.
This used a special hammer with smooth polished surfaces, to refine the shape against a steel stake held tight in a vice. No more annealing was required as this would have allowed the metal to stretch and the shape to distort more. Occasional marks made by the hammer edge were easily hammer out and again, the piece was moved rather than the hammer. |