Applying the Patina

river project, Videos, Work in Progress

A patina can refer to the natural colouration that happens over time to bronze, as the copper in the alloy reacts to oxygen, or it can refer to a man-made process where a chemical mixture is heated onto the surface of the bronze, to achieve different colours and effects. I am referring to the man-made process, and the above video shows foundry technician Becky Stevenson demonstrating how to apply a patina to one of my bronze pieces.

I then replicated what she had shown me, and once the pieces had cooled down I then applied two coats of wax, by hand using a cloth, to each piece to seal the colour.

This was definitely one of the more fun parts of the whole casting process! It was a chance to experiment and play with the different colours and effects that the application of heat and layering of the patina could achieve and I am super happy with how they turned out!

Removing Excess Metal from the Casts

river project, Videos, Work in Progress

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The photos above show the process and tools used for this stage of the project. As you can see I used a clamp to keep the casts in place whilst cutting and grinding off excess metal using a Dremel and angle grinder. I had to remove the cup, and all of the runners, risers and wax channels as they had all been cast in metal. This was hard work as the studio has been reaching 35 degrees Celsius, so I had to take frequent breaks and stay hydrated. On a few occasions the technicians closed the workshop completely as it was too hot to work in, and on other occasions I did the work in the metal workshop rather than the foundry as it was a few degrees cooler.

As well as removing excess metal I also used the Dremel and an engraving tool to work back in details that had been lost in the casting process, such as holes in some of the bones, and textures where they had been lost.

It took a bit of practice for me to get to grips with using a Dremel and angle grinder, as I had limited experience with only a Dremel, previously. However throughout this stage I learnt very quickly how to handle both tools properly and effectively, and I am really proud of myself for it- I have always been a bit scared of electric power tools but I pushed myself and am really pleased with how far I’ve come.

Before and After Clean Up Bronzes from Kat Outten on Vimeo.

The video shows the bronzes and aluminium pieces still attached to each other by the runners and risers, and then each bronze bone once I had finished working on them. As you can hear me say in the video I’m not 100% happy with each piece; I feel that the pieces of jaw both need a bit more work to add back in lost details around the teeth, and one of the bones in particular I want to go back and work into further as I am not happy with the hole (I broke two Dremel heads trying to fix it) or with some of the texturing on one side. However due to time constraints I had to move on to the patina stage, so that I would have some finished pieces to put in the end of year show.

Unfortunately I only had time to finish the bronze bones, so both brick casts and all of the aluminium bones will have to be finished when I get back from the Summer break. I am a bit disappointed by this, but the casting process is incredibly time consuming, and I want each piece to be the best it possibly can be, so I am trying not to beat myself up over not getting everything finished.