08/28/13

Results

I made a silicone mould and got an object out of it — yay! The silicone was quite viscous, had to be stirred before mixing with the catalyst, and I got it absolutely full of bubbles. None of them affected the mould where it was in contact with the object, but I think I’d have been in trouble if the object had been more complex. The bedding clay — good old Unleaded Toxic Soil — left a residue on the mould, which may have been a good thing, as the mould release didn’t seem to do much and I had a lot of trouble separating the halves; I suspect the clay film was the only thing that stopped the silicone sticking to itself. I’ve asked the supplier how many coats to use — I assumed 2, but maybe more are needed with this stuff. It’s also possible that there was air in the can and not enough actual spray came out. Maybe I could use mould soup between the halves? (Doug, if you’re reading this, do you have any tips?)

mould01

I also screwed up and didn’t leave enough room for a pouring vent, so I just cut a hole in the top of the mould. And poured some plaster in to see what would happen:

lips04  lips03

Not bad, I reckon. The little holes in the plaster are from bubbles in it, not in the mould. (The back’s yucky; the plaster didn’t fill up the mould, due to trapped air I guess, but I think a runnier liquid would be fine.)

This mould is too small to use for porcelain, I’ve realised, due to shrinkage of the latter, but I can use it for resin, which can then be worked on and used as a master for bronze or other metal if I want to. I need to get a bigger sphere to make the model for the porcelain version. I’m also looking into brush-on silicone as a cheaper alternative to pouring.

08/16/13

Testing

Lips! Testing the model out to see how it looks when cast, with a quickie paint job and varnish. Needs just a bit of tweaking, and I might have to do a resin intermediate copy and sand it, since so far I haven’t been able to smooth the plasticine enough where the lips join the sphere.

lips02

And a head. I wanted to try making a doll’s head, since I have a few ideas for dolls — heads only, no plans to attempt bodies at this stage. This was a rough model with a rough mould, and I was pleasantly surprised by how it came out, after a bit of cleaning up and smoothing with water. The mould wasn’t difficult, either. I think I can go ahead and try making a proper one.

head02

head03

08/9/13

A whole egg!

I did it! Laid my first egg!

Straight out of the lousy mould — this was the one where I reversed the ratios of plaster and water:
eye_egg01

Cleaned up:
eye_egg02

The arm egg piece after sanding. The clay came up pretty shiny, and that was just with a single grade of fine sandpaper. Hard to get into the lines, though — really need an electric tool:
egg_white01

Since the slip is porous — I think it’s a kind of papier mache — I daubed some sandalwood oil on a piece to try scenting it. I’ll see if the scent sticks around — might be fun. If it does stick I could go BPAL crazy.

I’m feeling pretty celebrational. My next goal is a quality mould that produces a cast requiring no work except cleaning off the mould lines and filling the pouring hole. And to finish ‘Looking for Aldebaran’, aka Minopotataur. Poor little guy’s been waiting for his fingers for much too long.

N.B. This mould was made from the plaster I got from the art supply section of B2S. Maybe real ceramic slip needs real pottery plaster, or maybe plaster of Paris is fine, just not optimal? One thing I have to watch out for is evenness of water absorption. The wall of the half-shell piece varies from about 1-3mm, which I’m guessing has to do with how I mixed the plaster and/or the WD40 that no doubt got into the mould.

08/7/13

And more eggsperiments

I was thinking that to make the eggs balance I would poke weights or slip up through the pouring hole and fiddle around with the weight until they rest in the right place. I don’t really want to flatten the bottom of the egg (or not more than a little); I want to fill in the pouring hole, and leave a pinhole for the fired clay version. That idea might — or might not! — work for horizontal eggs, but how about a vertical one?

egg201

egg202

Using paperclay slip, I managed to balance an eggshell pretty well:

egg302

But it was fiddly. The cast piece would definitely have to be in two halves. Which shouldn’t be a big problem, I hope — though at this point I’m assuming that Murphy’s law will affect every step of the process — and will also eliminate the pouring hole — though I think the mould should have a plaster channel for pouring out the excess slip, to cut down on mess and wastage.

Another WIP: this is a model I’m working on for casting in clear resin. I want to give it fatter, more exaggerated curves:

pillow01

Posted in Art |
08/6/13

Lindsay headers

I’m on a Norman Lindsay spree. Because I couldn’t choose just one picture, this site now has five Lindsay etchings for header images — ‘Bargains‘, ‘Self Portrait‘, ‘Spring Song‘, ‘Wisdom’s Devils‘, and ‘Thai Secret‘ (if that’s actually the title — not sure it isn’t a typo). And in the good name of excess here are four more that I love — ‘Leda’, ‘The Hidden Faun’, ‘She Arrives’, and ‘The Audience’.
Most of these images are from norman-lindsay.com.au.

lindsay01

lindsay08

lindsay17

lindsay15

 

Posted in Art |
08/3/13

Delightful trivia

From here:

One unsuccessful use of nitrocellulose was to make faux ivory billiard balls. The camphored nitrocellulose (celluloid) balls would sometimes explode upon impact, producing a sound much like that of a gunshot. As you might imagine, this didn’t go over well in gunslinger saloons with pool tables.