Saturday, March 28, 2009

Next steps in bringing my tiny elephant sculpture to bronze...

Here we are again, with my teeny tiny version of 'Senior moment'.
In the last installment I demonstrated how I made the original in a wax based clay.
So how do we turn one finished sculpture into a bunch of wax replicas ready for the foundry to then turn them into bronze?
My buddy Lee Wilson got busy making a mold. He's molded everything from the almost microscopic to bigger than a horse (see behind?). Nothing fazes Lee!
Here he is holding a work in progress on my miniature elephant...
The silicone rubber master mold is floppy (that's the yellow stuff), and needs a hard mother mold which can be screwed tightly around it to hold it in place (that's the white stuff).
I wonder is mold language developed similar to tool language, what with their male and female parts and all?With all the silicone rubber 'chew toys' laying about I was surprised and a bit nervous to discover from experience that mold makers seem to like to have a dog or two about the place. Must be the loneliness of the job.
Anyhow, Lee's are extremely well trained and only once got interested in sniffing the rubber when he was molding some cow bones for someone!
One rebuke put an end to that and they have NEVER messed with his handiwork, so I'm confident leaving my molds over at his place for extended periods.
So here he is tightening the bolts to keep the whole thing snugly together (you'll see why next)...
This is Lee's new toy! It's a wax injector. So for smaller stuff he can squirt wax into the mold under pressure (which will squirt out all over the place if the mold isn't securely held tight). It's quicker and more effective than painting the wax into the mold by hand on small things like this.

He experimented a bit to get the wax temperature and pressure optimal for various sized pieces. He mixed some pigment in with a blue green wax to make it a nice natural clay color. That way it's easier to see if any seam lines need cleaning up than if the wax is a day-glo color (plenty of waxes are very strange colors). You can see a few of my turtles, toads and rabbits floating about on the table too.
That metal plate with a hole in it is what he holds over the bottom of the mold when he squirts the wax in. Then it's left to cool for 20 or 30 minutes.
If the mold only has a narrow opening, he'll just use a washer.
Alright, let's pop that thing open and see what we've got!
Off comes the mother mold...
Wait for it...
And Lee has given birth to yet another teeny tiny wax elephant. Didn't hurt did it?
Family photo below.
Strange gene pool I'd say.If I can get the foundry to take some pics of sprueing up the waxes, investing and breaking them open I'll add them to a future post, then finish up with metal chasing (should hardly be any except grinding the bottoms), and patina which I will do myself.

My website here

Tuesday, March 3, 2009

Step by step how to make a tiny elephant sculpture

OK, so I'm making a very tiny version of my 'Senior Moment' sculpture. An elephant in Rodin's famous 'Thinker' pose. Above you can see the tools I used. Some wooden shaped things and some metal pointy things with little round blobs on the end, which I believe are called 'fillet' or 'fill-it' tools. Can't say for sure, but I think that's what they're called!
And of course my favorite tools, which I use the most, my fingers.
The first thing I did was reduce all the measurements I have in proportion to the size elephant I'm making. I'd taken proportional measurements from pics of elephants, anatomy books, pics of skeletons and what not, so each time I start him in a new size, I have measurements to rely on since I don't trust myself one bit to eyeball it as I go.
So above we see, from left to right, a base for him to sit on, his rib cage, pelvis, and skull.
This is the 4th time I've made him. Like a line of Mercedes cars to fit any budget!
So far the biggest is some 20 odd inches tall, and this guy is the smallest at 2.75" tall!
Here they are all together (above). Looks like a weird fish leaping out of the water, eh?
Now you can see why I don't trust myself to eyeball proportions. Everything looks so weird at this stage I'd be second guessing myself like crazy if I didn't know it would all end up looking right later.
Some muscles are added, so it's really handy to have anatomical reference standing by.
The head's bizzare looking, all duck billed and strange since it's just a skull, and elephants have the strangest looking skulls of just about anything.
Oh, I did take some liberties with the length of the thighs to get the pose to work. That's the case in all four different size versions.
I add the clay in small blobs. I find it's easier to add anatomically and keep the life in it, than scrape away excess and hope it doesn't lose its suppleness. That's just me of course, some people work subtractively from rock for instance. Mmmm, let's see, oh yes. Michelangelo springs to mind.
He was pretty handy with a subtractive approach, I'm sure you will agree!
Notice the ear above is made up of blobs of clay depending on where the form goes. I didn't make a flat bit of clay and stick it on. There's some folds appearing around his legs and mouth as well as muscle and fat taking shape.
This is the only size of this piece that didn't need any armature support at all, since the clay is very light and sticky, and he's so small.
The clay I use is jmac wax based plastilene, the softest one they do. It can get a bit messy if you aren't careful. When using tools, I go with the same approach I learned when painting. Get the biggest one you can that will do the job, that way I don't end up with over fussy patting effects, just nice clean broad strokes. That's the most important thing to maintain. Adding details is easy later, but taking an over fussily detailed sculpture back to something more elegantly simple is much more difficult. Not least because you don't want to scrape back all that hard work you put in!
I might fiddle around with him a bit more, but for now he's pretty much done.
One thing I've learned making small stuff which is cast solid (not hollow like bigger stuff) using a more brittle plaster investment than ceramic shell is to make sure not to have any deep recesses with sharp bottoms. You have to smooth them out with the round blob on a stick tool. Otherwise, bits of investment fall off and float around in the bronze during casting, only to surface as pits all over the place. A tiny amount is tolerable, but if you have lots of grooves cut into your original piece, say with a knife or other sharp tool, it's bad news later.

The pic below was sent to my man at the foundry to show him where the tunnels are and see if it will give him any problems with mold making and casting. The mouse is for scale (he knows how big it is) since if you cast solid bronze beyond a certain size, you run into all kinds of shrinkage problems.
Especially if it has skinny protruberances, since ideally the metal is runnier and hotter for skinny things (or it won't make it to the ends), but cooler and thicker for larger bodied things (or it will shrink away from the mold as it cools). Both in one go can be problematic since you can only pour the metal at one temperature for the whole piece.
If elephants are scared of mice this guy must be terrified!
Keep your eyes peeled for the finished bronze (I'd say give it a month or two)!
I'm pretty excited to see it all done!