Winter warmer: cast glass in the wild

Recently I've been pondering the possibilities of taking my cast glass outdoors.  I've done some sculptural pieces for a roof garden in the past, and there's no doubt that natural light brings out the best in glass. Light filtering through trees and the sun's changing position throughout the day mean that the work gains a fourth dimension: time.

But rather than the glass sitting on a plinth, I'm now considering how it might actually interact with the natural environment - using what already exists to support and display the glass. So a crisp autumn day this week was the perfect excuse to try out some ideas in the Clent Hills. OK, I had to improvise a bit, as I haven't designed special pieces.  But I think there's some potential to take the idea forward. We need more wild glass!

If you'd like to see more pics, this Wild Glass link will take you to the full set on Flickr.  To find out more about the wonderful location they were taken, visit the Clent Hills National Trust page. It's a great place for a walk, and there are some rather good pubs in and around Clent if you like a Sunday lunch.

Ten Steps for Slip Casting with Wax

I've had some 'work in progress' shots taken this week - including some wax models I've been building (there's a picture at the end of the post). Well, it's finally prompted me to share a technique I learnt back in September.

I was lucky enough to get a spot on the Kiln Casting Masterclass with Angela Jarman at the Glass Hub. Angela is a brilliant, down-to-earth teacher - and was happy to share her experience and techniques.  If you get chance to take a class with her, don't miss out! 

But it was one technique in particular that caught my imagination: slip casting wax in plaster. It's relatively simple - but allows you to make multiple repeats in a relatively short space of time.  (Which, for someone who normally works with cardboard, was a revelation...I have to admit, I almost cried with joy!)  The pieces are also hollow: a BIG advantage when it comes to making a lost wax casting, as there is much less wax to steam away.

STEP ONE: Switch on your wax pot! We've got a specially designed (if somewhat ancient) wax pot in the studio.  You can use also use a double boiler over a hob.  Two suggestions for safety: never melt wax over direct heat, and never leave your wax pot unattended. 

STEP TWO: You need a plaster mould.  It MUST be what I'd call a "drop out" mould - one where you can turn the mould over and your material will...drop out. Something without undercuts, and that doesn't get narrower towards the top. 

STEP THREE: The mould needs to be saturated with water.  Drop it in a bucket of water, and leave it until bubbles stop appearing. (If you wander away and forget, don't worry - but don't leave it for hours and hours, as the plaster will eventually start to deteriorate). The mould at the bottom of this picture has just been dropped in the bucket - and you can see some big bubbles. 

STEP FOUR: Remove the mould from the bucket and blot any surface pools of water away with some kitchen towel - or they'll spoil the surface of the wax.

STEP FIVE:  Fill the mould with wax.  A handy tip from Angela was to overfill slightly - the wax then grabs the edges of the mould, and can't shrink away and distort so easily. Though you probably don't need to be quite as messy as I was in this picture..!

STEP SIX: Wait until the wax starts to form a skin where it touches the mould - you'll see the wax change colour (and become matt rather than shiny).  This skin will get gradually thicker. Once it's thick enough to have picked up any detail in the mould - and to hold its shape, you can tip the liquid wax that's still sitting in the middle back into your wax pot. In the case of my moulds (the triangles have an edge of 100mm / 4") this takes about 3 minutes.  In the picture you can see the skin forming best at the corners of the triangle. 

STEP SEVEN: Give this internal surface a quick mist with a plant sprayer - so the remaining hot wax is chilled down.  You'll see the wax change from shiny to matt as you do this.

STEP EIGHT: Dump the mould (with the wax still inside) back into your bucket.  OK, maybe "dump" is a bit strong, perhaps "drop carefully" would be better!

STEP NINE: Once the wax is chilled, it will shrink away from the mould and should release. You may have to help if you've got drips of wax clinging to the sides of the mould (like with my messy pour...) But if it was a neat and tidy pour, the wax normally floats away from the mould all by itself.  

STEP TEN: HURRAH! You have your first wax.  Now repeat, repeat, repeat - and build something new and exciting from your components. This is what I've been making with mine: 

Work in Progress (Georgia Redpath)
(photo: Simon Bruntnell)