Slipcasting Fun: Part II

Despite the unfortunate conclusion of our 8 week super-duper slip casting class, the slip-casting excitement continues. If you haven't been reading every single post we've written this year (shame on you!), the class taught us all the steps of casting from start to finish; the goal: to make ceramics mulitples of a form quickly, easily and awesomely.

For the class, we wanted to make something special for L&G and so we decided to create our own original L&G Chalk-It-To-Me piggy bank! Here's a little trip down memory lane of how this little piggy came to be:

We quickly sketched up (I'm a great sketcher, right?) a simple & minimal piggy with a capsule-like form that I thought would be a nice easy form to cast.
From there it was as easy as 1, 2, 3!!

STEP ONE: Make a master form. In order to create the mold, we need to create a positive "master" pig that is an exact specimen of what we want our cast forms to look like.
Little did we know...the first step of making darn thing was a total ordeal. It didn't have to be...but I just ended up making it that way. Go figure...

I used my first instinct...which is to use our handy dandy laser cutter from Chikabird.
I figure I can draw the shapes in layers and build the form up like a topographical map! This was my way of it getting the form close to perfect versus just making it from clay. Clever right? But In cardboard....not so much. Now you're probably asking why the hell I used cardboard to build the form...that's a very great question. Well....I decided to use cheap-o Sculpey (craft 101 style) thinking that I can roll out the material and drape it around the form, then bake it and sand it afterward!
I thought it wouldn't be such a good idea to use acrylic for the laser form since it would melt in the baking process...and so why not plywood you ask? Well, honestly... I don't know! Why didn't you mention that BEFORE I started making this?!?So here it is with the Sculpey draped over. I think the last time I used Sculpey was in middle school or something. I realized there was a reason for that...this stuff is horrible to work with!! Its too soft and I kept making finger marks all over as I was handling it.
After going through the baking process, the rough piggy form was made. But then somehow there were little cracks that formed because I either baked it for tad too long or there were areas that were too thick! UGH! But by that point, it was no going back, those cracks could be easily filled right?...can't you just feel the suspense?

Then it was onto the sanding phase. My favorite!! Who doesn't like to spend HOURS sanding laboriously using sandpapers between 100 grit and 1200 grit...and on top of that, I also had to use Bondo to fill in all sorts of indents and fix all the cracks from the baking process since the Sculpey surface was so bumpy. Can someone remind me why I used Sculpey??
After that it was on to the priming stage. This is where I had to spray the whole thing with primer, sand between layers, and repeat this step for 2 more times.
And Voila! Here's the finished piggy model!
And you think after attending industrial design classes for 3 years that I'd know something about model making!! NOPE! If anything this proves that I shouldn't be making models!
Despite all that, I hope it was somewhat useful to see my process... Since now you know all my secrets and know NOT to follow any of the same steps!
So...now that we're done with step one...

STEP TWO: Prepare the master for mold making. This was actually easier since I just had to carefully build up the first half with clay covering up to where the parting line is (roughly marked on the pig). It was critical to line up with the exact mid-point of the pig. Then it I had build outward leaving about an inch and a half of border around. Lastly, the most essential part...a pouring snout that connects to the pig, which is an opening that will allow the slip to get poured in for the slip casting process.After all that, we then used these plywood pieces to build four walls around the clay form. The corners and edges all had the be sealed with clay so no plaster would leak out. The master shape also needed some mold soap so it could separate easier from the plaster.

STEP THREE: Pouring the plaster to make the actual mold!We used special slip casting clay (Plaster No.1) to make the mold. This involved measuring the volume needed and then following some equation of measuring out the 1/3 plaster to 2/3 water ratio. (Here's a WAY better instruction, HERE!) We then poured the mixed plaster in and then let it sit for awhile as it hardened and set. Once its hard, we took the walls off, leaving the master pig in the plaster...and then poured the other side in the same way.So this is what the two piece mold looks like! You can see the one on the right is the top half, and the one on the left is the bottom half with the feet. Even with all the mold soap-ing we did, the piggy was nearly impossible to get it out of the mold. So we had to use some major force and drill into the snout and pry it out...this made me almost want to cry after all the work that went into it!! But it was either doing that or leaving it stuck in the mold...so...not a whole lot of options.
So this is what the master piggy looked like with all the cracks all over from all the abuse...not too happy looking. Unfortunately we won't be able to make another mold with this again. Sad...

See? TA-DA! It is easy as 1,2,3!
...It's just that every step required 50 intermediate steps that's all!
Of course this isn't the end of it!! We've still got to show you the slip-casting process and the finished products later!! Just be patient it's totally gonna be worth it!