Defining 'Non Place'

The final piece will comprise of the cast brain suspended in a void surrounded by words that I associate with defining what the theme 'non place' is, both in its physical and non physical form.

The cast will be bonded to a sheet of clear float glass with another sheet placed behind it.  This provides up to four planes on which I can display my words.  The sheets will be situated in the foreground of an infinity mirror so I've decided to incorporate the second sheet into the mirror's structure so the rear plane will be reserved for that.

Having chosen my words I listed them in MS Word and then worked the fonts to be reflective of the word, almost akin to onomatopoeia.

I had the lettering printed and cut onto vinyl with an additional copy where the wording was flipped to compensate for being applied to the reverse side of the glass  I then laid out the glass and the wording and marked the location of the cast brain.  This allowed me to rearrange the wording into a structure that I was content with.  Since each plane is 3mm apart, I positioned some of the words with overlaps to help create the sense of depth and movement.

Once the words were placed and the remaining glass areas covered with clear vinyl I then used hydrofluoric acid to etch out the lettering.  The acid is exceptionally dangerous to work with so a risk assessment has to be carried out for each piece being worked on and personal protective equipment is essential, e.g. suitable rubber gloves, full face respirator, rubber apron etc.

The etched lettering has captured some texture but has retained a transparent property, this would not have been achieved through sandblast etching.

I then applied a silver reflective vinyl onto the rear of the second pain which gave it a 'one-way mirror' property.  This is required to create the infinity mirror.

The next stage is to complete the cold working of the cast brain so that I can start to bring the different components together...

Breaking through the grey matter

The cast went into the kiln at 3pm on Thursday 4 October and now, 10 days later on Saturday 13th October, it's time to find out the results.

On first inspection the red glass hasn't moved from its saucers.  It has melted as expected however it would seem the exit hole was too small for the glass to seep through.  The surface has a crazed cracking as a result of the difference in the glass to terracotta cooling coefficient causing compression in the glass.  The glass surface is also heavily devitrified making it look opaque even though tests confirm this is a transparent glass.

In contrast, the large pots have discharged all of their glass.  An inspection of the pots shows that there has been some colour mixing inside the pot.

Looking at the cast for the first time I can see that the colours have mixed really well and that the turquoise blue has created some very deep colour tones.  On closer examination I can see that the mould has not been filled with glass.  There isn't very much left in the pots, just the usually traces expected, and there isn't much in terms of over spill from the locations the glass poured down.  I have to conclude that the weight used was insufficient despite adding an extra 100g to compensate for the residue and any overspill.  This could have resulted from weighing the clay after it had dried out a little and therefore shrunk to a lesser volume.

I considered leaving everything in place and adding the shortfall in glass to the pots and re-firing however I had to be satisfied that the mould could withstand another firing.  I noticed that there were some cracks in the plaster which needed further examination.  There were two cracks that clearly moved from the upper surface, down the side and underneath.  I could have reinforced the mould by binding it with high fire wire however when I inspected the cracks it transpired they all met underneath and the likelihood was that the mould would split if re-fired.  This proved to be the deciding factor and I decided that I had only lost less than 10mm and that I could work with this.

I'd no sooner started to scrape out the plaster form the top plug when the side cracks started to move, boy was I glad I chose not to re-fire!

I didn't want to cause any unnecessary stress in the glass so I took my time scraping break lines in the plaster and freeing it off in small sections.  It didn't take too long to free the glass entirely and after a quick brush down and wash I could see how well the glass had picked out the details of the mould, particularly when compared to the silicone rubber mould taken from the same plaster mould.

The detail below shows the difference in the glass finish from the areas that have been in contact with the plaster from those that have been free from contact, at the top of the mould.  This detail also shows a shoulder that has been created from the overspill of the glass pouring down onto the mould.  I will a lot of cold working both on the finished surface and also on the underside as this has to be completely flat and smooth to ensure a good bonding with its carrier glass for the final display.

Making mental connections

Last week I experimented making veins and synapses using flameworked rods.  I was happy with the results and have considered the best approach for making them.

It was easier if I made separate pieces, shaped them and then attached them.  This way I could reshape elements as I added new parts.  I also had one of the plaster plugs handy to check the size and dimensions.

I've attached a couple of video snips showing the process. I hope you enjoy them.

Hi Ho, Hi Ho...

...a casting I will go!

Now that all of the mould work has been completed I can now cast the glass.  My design focuses on the left side of the brain which, amongst other functions, is also the side of the brain responsible for creativity and art.  Because of this, I've chosen Bullseye crystal clear as the core glass and have chosen some red, blue and yellow colours to add an artistic accent.

The plaster mould is placed on a bed of fibre paper to protect the kiln base.  Kiln furniture is then structured around the mould and the plaster plug is suspected into the hollow using a ceramic rod and the wires integrated into the mould.   The overall structure is quite tall so I have make sure everything is level and at least 25mm lower than the bottom if the kiln's heating elements.

The pots are filled with glass and placed on top of the bars.  The kiln bars have been placed to create gaps down to the void in the mould for glass to pour down to.

I've placed the red glass into pot trays that have had a 6mm hole drilled through them.  The trays have been placed on top of the pots.  I'm aiming for the molten red glass oozing through the smaller hole and causing it to trickle mix with the clear and colours below.

The firing is a 9 segment schedule which includes a lengthy venting first stage.  This is to allow all chemical waters contained in the plaster moulds to be steamed out.  During this stage all of the kiln vents are left open to ensure the vapour can escape and not harm the components of the kiln in the long term.  The schedule should take just over 4 days as I follow the Bullseye guidelines on annealing a thick slab; in this instance between 75-100mm.

Bouncing ideas...

...you'd think with a rubber brain it would be easy to bounce ideas around,

Here is the silicon rubber mould.  It took some very gentle persuasion to get it out with damaging the plaster mould.  It's the first time I've used this specific brand of mix and I'm reasonably happy with the results although there are quite a few little nodules formed that aren't due to the original mould so must be a reaction or peculiarity of the mix.  It won't cause any issue as they'd be easily dealt with in any subsequent plaster mould.

The old grey matter

I've decided it might be a good idea to have a back up plan, just in case the glass casting doesn't go awell as expected, so I'm going to make a positive mould that will allow me to repeat the process without several of the steps.

To do this I have set up the plaster moulds as they would be for accepting the glass.  Instead of glass I am going to use a silicon rubber mix.  I'll be using a Tiranti solution which is a two part mix; the base is Tiranti T28 and the catalyst is T6 to a mix of 20:1 (or 5%) using a weight measure rather than a liquid volume measure. I will also use an Alchemie R5 release agent which is sprayed in two coats over the surfaces of the plaster cast to help remove the silicone once set.

Measure the compounds accurately,  I need 600gms of base and 30gms of catalyst, and mix them very well together.  This catalyst is clear which makes it difficult to see if the compounds are fully mixed, some compounds are coloured which makes this stage a lot easier. 

Mixing will fold in a lot of air so sit the mixture aside for a few minutes to allow the air to bubble up to the surface.  In the meantime inspect your plaster moulds to make sure they are thoroughly clean.  Once everything is clean and the bubbles have cleared out of the mix it is time to pour.

Pour into the mould slowly, allowing the compound to gently rolled over the contours of your mould which will stop any air being trapped and bubbles forming in your end mould.  When the pour is finished tap the sides of the mould and bang the table top many times as this will encourage trapped air to bubble up and release.

Now let it set.  This particular mix will be set in about 6 - 8 hours but will finish curing up to 24 hours.  Leave your mixing jug and spoon alongside your mould because once it is dry then the mix inside the bowl will be too.  You can then just pull out the spatula and the whole mix should come in s singular piece.

Getting inside my head

Now that the plaster is dry I can break the mould out from the shutters.

 

I'd placed the brain form onto a bed of clay to stop ant plaster seeping underneath.  I removed this clay first and discarded it (all the clay will be cleaned and recycled) and then I carefully removed the modelled clay as I will need this later for calculating my glass requirements.

I then spent as much time as needed to make sure the mould was very clean as any particles of clay remnants will be found by the glass and be very noticeable.

In the picture above you can see the main mould and also the plaster plug that will help to create the hollow.  The pictures below show that some damage was suffered when removing the clay; the plug suffered a crack on the stem and the some plaster crumbled from the frontal lobe area.  

I created a new plug however this time I made the stem thicker so that I can carve it to shape and size.  I have also incorporated a section to create an infill for the lost frontal lobe area.  Both parts have had wired inserted for strength and also to assist with suspending the plug at the casting stage.

Now to work out how much glass I will need. To do this I will use the water displacement method. I have a sizeable lump of clay and should use a larger measuring jug however I've only a 1L jug to hand so I will split the clay into two lumps and carry out two measurements. 

I use a measuring jug and fill to the 500ml line and, one at a time, I place the clay into the jug.  This displaces the water causing its volume to increase.  I note the new levels - 800ml and 750ml.  I then deduct the original water level (500ml) from each reading (800-500=300) (750-500=250) and add the two figures (300+250) to get my overall clay volume = 550ml.  This means when I come to the stage of prepping my glass I will fill a jug with 500ml of water and add as much glass as it takes to displace the water to 1050ml (500ml water + 550ml of clay)