Sand Casting at Liquid Glass

[Pat from Canvey]

I've already voiced my thoughts about the cracks to Charlotte in an email as I didn't want to cause controversy on the board. In a nutshell, the cracks seem to develop where there is a larger concentration of the Bullseye glass in the caste. Glassworks Services Ltd in their Batch Specification Comparison Chart for Philips casting pellets gives the following
Philips Gaffer 3300 (if that is what was used) 89.7 calculated COE
                                                             96.0 measured  COE
None of the other casting pellets in the chart have a COE nearer to Bullseye at 90 COE

So pleased that your final piece came out so well Charlotte. The cracks in two of my pieces are about 2 inches long and are at places where there is a thicker concentration of Bullseye glass. They have not spread outwards towards the edges of the pieces.
I prefer the second picture of your final piece because the bird shows up more but must admit a preference for the murrini one as I feel that the symbolism of the final piece will be lost on some people. How did the  piece with the silver torchon leaves come out. I did a bit of lace making years ago and still have my stuff around in the bedroom. Glass took over and I didn't pursue the lace making but a friend still does.

[theflyingbedstead]

My main cast has the silver lace in, and the non-figurative tin-can piece has a single plique-a-jour (in green) silver lace leaf.  In the main cast, the silver melted into little silver balls where the wire crossed, so you can just make out the leaf shapes and lace pattern (underneath the central tree).  In the sunlight the silver glints away, but you or the piece need to move to be able to see it!

I am not sure about the cracking issue...the Bullseye murrini chunks in my square cast have more mass than my ivory figure, and yet that piece is ok so far. The cracks in the ivory figure piece started out quite small, but they have grown enormously since I got it home, and have spread to the edges.  I know that there was a powercut during the annealing cycle for these pieces.  I suppose that it could be an incompatability with only some of the Bullseye colours and the Phillips casting pellets?  That's why I want to remelt my test, to see what happens!

[Black Heart Beads]

At long last I got around to taking some photos of my pieces.

This is the only one that did not crack although it has fairly large figures in it.


This one didn't work in many ways and although it has some cracks I think it was my errors that caused them. The cracks do not stem from the larger inserts but the flower bits on the base of the cast.


farting mermaids


and my final piece that has cracked badly

[fionaess]

I am so glad I came back to these pages... there is so much that I haven't seen... amazing work ladies.. really wonderous..

Farting Mermaids.......... oh yesssssssssssss   

[mariag]

So good to see all of the photos, some stunning work there ladies & Sam I love the farting mermaids

[theflyingbedstead]

Oh Sam - they are stunning and beautiful...all of them!  Whilst I was just making my test pieces, yours were properly composed, finished works of art!

I'll have a play and see how I go with remelting my torso piece.  It is interesting that your pieces with the ivory figures have cracked too...but out of all of your figures that I would have worried about, the aventurine one is fine!  My bundles of mosaic cane which have aventurine glass in have de-laminated.  I spent the weekend coaxing them back together with 700 degrees C!

[Pat from Canvey]

I love the way the seaweed is flowing in your final piece Sam and the fish are ace. Hopefully the cracks will not develop any further.

[garishglobes]

They are all absolutely beautiful, I really like the top one with the figures - but that final piece was really extra-special.
It is a real shame that it cracked, particularly when so much thought had gone into it. Again though, there seems to be a crack right up the side where no thick inserts were...

[Black Heart Beads]

there seems to be a crack right up the side where no thick inserts were...

The very long crack on the left side goes through all the bubbles. The bubbles were inserts as I made clear hollow balls so I could place the bubbles where I wanted them. Even the pebbles have cracks around them and they were not very big. Everything I inserted except the fish and seaweed has cracked on that cast.

[garishglobes]

Ohhhh, yes.... I'd completely forgotten you did the bubbles that way!
This cracking thing is a bit wierd, the marble I put in the second cast I did with the pear was just as big as the one for the final piece, and yet that hasn't cracked at all.... and as you say, those pebbles don't look that big, relatively.
I wonder if it has something to do with the thickness of the cast.

[Hotglass28]

What lovely slabs of glass, I enjoyed looking at all your work girlies!

I haven't read all the posts but I see that your worried about the cracking.  If its not the coe miss match then it could be that the annealing was not done properly. Thick pieces take hours and hours to anneal and cool.  Could they not of done the firing properly?

Anyway.  Lovely stuff all.

Denise

[Lloki]

Really, really beautiful (I especially love the tree one - love the roses). I hope you can figure out the cracking issues, this looks like a technique you can have an awful lot of fun with Truly beautiful!

[turnedlight]

I love the farting mermaids - brilliant The compositon of the final piece is really lovely too.