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Wednesday, October 29, 2014

Plasmodesmata glass sculpture




By now the 'Plasmodesmata' piece will have been gifted to it's intended recipient, so I feel I can share the final piece and all the details over in my quiet space of bloggerdom. I compiled an overview for the client, part inspiration, tests and processes which I though I would share on here, useful to have it all in one spot.

This commission was designed as a retirement gift for a botanist who had studied ‘Plasmodesmata’ for the entire span of her career. That’s what I call fascinated dedication!
The main focus is the plasmodesmata, pictured below. Put simply it's a communication channel in between plant cell membranes.
Plasmodesmata illustration




At our first meeting I was given 2 books and a sheaf of scientific papers and illustrations to familiarise myself with the subject of plasmodesmata and plant cell structures. For our second meeting I had some drawings and models to show, some ideas for a work… other to aid my understanding of what I had read.
Most importantly I felt I wanted to create some context for the main diagram (the plasmodesamata). I noticed that many of the samples of cell tissue came from the Azolla plant and decided to use imagery based around it, drawing upon a few details. Rendered in low relief (bas-relief) the imagery moves from small to microscopic: Azolla foliage, Azolla cells, a single cell, x-section of plasmodesmata to a detailed diagram of the plasmodesmata.




The most challenging part was deciding on an overall shape for the sculpture. I chose to work with plate 49 on page 104 of ‘Plant cell Biology an Ultrastructural Approach’. I liked the accompanying text that talked about the plate being “largely symbolic” as it referenced the relationships between all cells after a study of individual cells and components. I felt that fitted in with my desire to create a story or context for the plasmodesmata model.
I achieved the final ‘shape’ by tracing the root cross section over and over until I found a unit of cells that formed a ‘good’ shape. That means what I found to be a pleasing shape.



Here is the final shape in clay with some progress shots of the Azolla and plasmodesmata imagery being moulded into the final form.
 






The way I hightlighted one cell among many was to draw attention to the cell by casting it in colour while the rest were in clear. I chose a crystal that has Didymium (praseodymium and neodymium) included in the chemical mix. It has a wonderful quality of changing colour depending on the kind of light it is viewed in. Green in cool light (fluorescent) and a pink shade in warm light (daylight). I thinks it’s rather cool and I like how the colours are evocative of Azolla. The pictures below are from some test pieces I made for texture and colour.




Now for some process shots of some casting! To get the ‘plant cell wall’ effect each cell was cast in glass separately. 

  • I made a mould of the clay original so I could replicate the shape in wax. 
  • After some trials I found that wax was easier to cut up into the shapes I wanted and retain their form.
  • I made moulds, steamed the wax and cast each cell separately.

Each ‘cell’ after demoulding was ground, sawn and sandblasted to refine the shapes, clean the surfaces and create the ‘tooth’ required for the fine veiling of bubbles. 


Here are all the pieces inside the final mould, ready to be recast. The delicate lines of the ‘cell walls’ are formed by lots of little bubbles created when the cast pieces meet each other in the final firing. The firing is slightly different for this process as the structure of the ‘cell wall’ or veiling can be distorted by too high a temperature or by too much heat.




After the glass cools down, it will be ground and polished. After a second firing the surface is not as clean or smooth and requires grinding and polishing to get the surface back to a high reflective sheen.
I also sandblasted the back of this piece because the texture was too gritty, a result of 2 firings. I hadn’t realised I would need to cold work the precast pieces more than I did to achieve the normal silky surface of cast crystal.  
I softened the sandblasted surface by rubbing it with pumice.
Finally, there is an engraved inscription at the base.




Thank you to Bilk Gallery for the opportunity to make a piece for such an interesting project, and to all the support and advice from fellow artists at the Glassworks.