This week I started my workshop rotations and I began with pewter casting.
Preparing the Plaster
The first step would be to make sure that the plaster was bone dry. The blocks we were given were already dry so that was fine, but it’s something to remember for the future if I want to make my own block of plaster to use.
I started with a block of plaster which I smoothed and levelled with a plastic strip and mesh.
Once the block was all smoothed out and level, it was time to draw a design. I had picked out quite a small block of plaster and I had never done this before so I decided to come up with something I thought was simple. I drew a fish design onto the block and began carving it out with metal tools.
Once I had finished my fish, I created a funnel so I could pour the melted pewter into the mould.
The final thing that I needed to do was carve a very shallow line from the bottom of the fish to the top of the block, next to the funnel. I needed to make sure that this wasn’t too deep to ensure the pewter didn’t try to fill that area.
In terms of carving out my shape, this was all there was to do, now I needed to melt some pewter in order to actually make an object.
Melting the Pewter
Melting the pewter was a lot easier than I thought it would be.
- blow torch
- melting/pouring pan
- stick of pewter
- thick gloves
- pliers (to hold the stick of pewter when it got too short)
- a brick
- sand pit
- wooden surface
The first step towards melting the pewter was dusting some talc powder and then clamping the plaster to the small piece of wooden board and sticking it into the sand pit.
I put one clamp on each side of my plaster and placed it on the board. I needed to make sure that I didn’t put the plaster right at the top of the board so there was space for the pewter to run down to make sure that more of it goes into the cast.
All that was left to do was put it in the sand. I made sure that it was stable and slightly tilted back.
The next step was to melt the pewter. To do this I first put on some gloves for safety. Then I held the pan in one hand and the stick of pewter in the other. I placed the end of the pewter into the pan so that it would melt into the pan which was on a brick so that would work surface didn’t burn.
I then asked somebody to use the blow torch to melt the pewter. This did not take very long and soon it was time to pour the pewter.
Once the pewter was melted I poured it into the mould and waited for it to be set. To test wether or not the pewter was set I tapped the pewter with a knife. When it made a solid tapping noise, I knew it was set.
I then turned my object out into the sand and then, using pliers, I placed it on a piece of wood to cool it down.
Once it had cooled, I used a jewellery saw to cut off the excess pewter and I was left with a finished piece.