The Eye of the Storm

Nine little molds patiently waiting for the chaos to ensue.

By the skin of my teeth I finished the ninth and final mold for the 2011 Christmas ornament, pulling it apart from the original just twenty minutes before we left for a weekend jaunt to a horse show.

They have to dry thoroughly, so I could probably start pressing around October fourth. I'm determined to fully stock my Etsy store by the first week of November for Christmas shopping, but we'll see how that goes! As we all know, life seems to enjoy throwing ringers, and I'm certainly no help. I generate my own like a fractal equation. Wish me luck!

Here's my studio floor after mold-making, strewn with clumps of dried clay and plaster shards. The remnants of my madness, and a metaphor for what's to come.

"This suspense is terrible. I hope it will last." ~ Oscar Wilde

The Eye of the Storm

Spaghetti Monster Be Praised!

Success!

Oh thank goodness - it worked! Above is the second press mold and it popped off easily with the tweaks. Seven more to go.

What a tease...the plaster looks like a block of Fluff! 

Here's the ornament inside the mold box with freshly poured plaster (above). My mold boards are clear acrylic, which allows me to see what's happening inside. The boards are like a Chinese puzzle box until you get the hang of them, but this simple "L" design works great. I have this long version, but also a shorter version for small pieces. It's not technically necessary, but much handier. 

The boards are placed alongside the edges of the backing tile and clamped into place. Then the seams, where they meet each other and where they meet the backing tile, are caulked with earthenware clay to prevent plaster from oozing out.

But placing the boards alongside the tile edge resulted in a mold a snidge too thin for my liking, even though I mixed three pounds of plaster. It'll work just fine, but I'll have to be careful. The forces involved with tile pressing are pretty strong thanks to Sir Squish, my tile press. This fantastic press works like a charm because he's geared, and so a modest pull on his lever results in a lot of force on the mold. So much so that I've unintentionally broken a couple of rather hefty molds! 

But we want all that force because it ensures a good impression and a dense compaction of clay particles. This is my (silly) theory, and it is mine... ahem....AHEM...I think "shocking" the clay helps to dampen warp. I wonder if by smashing the particles through a slab roller (such as my Derby) helps to shock them into a new alignment, and then smashing them again in Sir Squish reinforces that alignment. 

I suggest this for two reasons. First, I've noticed zero warp in my round ornaments, no matter how big they are, implying that a lack of the "suspension" span between any corners prevents a sort of "pull" those corners could exert - but it also implies something about the particles and how they were aligned in the process. And second, I noticed in the fire of the 2010 ornaments that only those pieces that lined the side of the convection vents between the broken shelves warped - all those away from those vents, in the middle, were perfect.

Here you can see the clay caulking along the seams.

Anyway, what I decided to do to create a beefier mold for the next pour was to pop the boards up onto the backing tile. It's something I've been meaning to try, but I was a little worried about the boards sliding around.

Oops! A bit of a spill there on the right. I need to find a new mixing bowl for plaster. The one I'm using is rigid and large, so spillage is unavoidable. I need one strong enough for plaster's weight and the effects of mixing, but also flexible enough to squeeze in a spout when pouring. It has to be cheap, too, which is why thrift and dollar stores are great suppliers.

I was so happy to find this approach worked great, so I'll be doing this for the rest of the molds. I want a really thick block while also minimizing the use of plaster, and this piggy-back approach delivered.

We don't want to get thinner - we want to get fatter! Mission accomplished.

You can see the difference clearly in the image above. The thicker block on the right will let me press much harder.

You may be wondering why I'm making so many molds for an edition of one hundred, which when divided, allots about twelve castings per mold (excluding the ninth back-up one). Well, the first reason is that I want to be able to choose the best molds for production, those with the least amount of bubbles or other hiccups that require clean up later. The other reason is that for some inexplicable reason, some molds work better than others in terms of pulling, and I'd like options in this, too. Same methods used in making them, but oddly enough, each mold has its own personality and you don't learn it until you use it.

Mostly, however, it's because of the clay itself. Clay is abrasive while plaster is rather soft, even when cured. So every time I press clay into a mold, the clay abrades the plaster, progressively wearing down the fine details and edges of the cast. The moisture in the clay also compromises the mold, and after about six or eight castings, it can be too damp to use and must be set aside to dry again. I want each casting to be nice and crisp, so I'd rather pour a few more molds to ensure each collector gets a faithful piece. I also don't want to be slowed down in the casting process - when I get in a groove, I go. Creativity has its own inertia. So setting a wet mold aside and grabbing a fresh dry one keeps production humming along.

Technically, I should be able to get about twenty five to thirty pressings from a single mold. Ideally, I'd be using Hydro-Stone® instead of regular molding plaster because it's harder and would yield more castings, but its mixing process is still something I have to perfect. So for now I'll leave that for another day and groggier clay.

I'm really excited to see how the black porcelain turns out. Black is a rather unconventional color for Christmas, I know, but can you imagine how it'll look with its purple ribbon and the glow from tree lights?! Fitting for a Friesian I think! 

"The painting leads the painter, and it becomes an intuitive experience." ~ Ardath Davis

Spaghetti Monster Be Praised!

Last Sabotages First

The one and only mold for the Unicorn.

This week is a mad dash to make ten open-face press molds before Thursday. One for the Unicorn (above) and nine for the 2011 porcelain Christmas ornament. They need to dry for about twelve days, then I can start casting.

The Unicorn was straight-forward. Mix, pour, pop apart. Done. Yes. No hitch. That couldn't be said of the ornament, however. Of course it couldn't. Silly me! It had to present a problem right out of the gate, in the making of the very first mold! Mix, pour, pop apart. WHAT. ACK!

Let me backtrack. I don't plan on making rubber masters of these ornaments because the integrity of the limited edition is important to me. So each of the 8-9 press molds needed for the edition of 100 are cast directly off the clay original. This means that if damage occurs to the original during this process, I have to fix it before I make another mold. Easy enough with oil clay. It does mean though that all I have is the original, so if it gets hosed beyond sensible repair, there would be no 2011 ornament.

On top of that, thinking it was efficient and clever, I simply resculpted the old 2010 ornament clay original, filling it in and paring it down to create the blank block I needed for the Friesian (which also means the 2010 ornament truly is done since I no longer have an original to mold). 

What I'd forgotten, however, was that in the process of making the last press mold for the 2010 ornament, it got pulled off its backing, too. All the heat generated by the curing plaster and the subsequent pulling had eventually loosened the oil clay from the backing tile and that bond had to give sometime. But since that last mold was a back-up freebie, I slap-dashed it and simply affixed the clay original back onto the tile with double-sided tape, then proceeded to make that last mold. This trick works great for resin or rubber, but barely for oil clay, for obvious reasons.

So flash forward to now: as I pulled the first press mold for the 2011 ornament apart from that 2010 backing tile, this happened:

CRIKEY! There it is, stuck in the mold. Those bulges along the edge are the casts of my thumbprints from squishing the "caulking" clay into the seams of the mold boards. Kinda pretty. You can even see the streaks left by the double-sided tape on the clay.

Good gravy. It was wedged in there really good, too. When I screw up, I certainly do a good job of it. At least I can find satisfaction in that.

But what to do?! Tearing this thing out meant it was a wash - the damage would be too great and I'd be left with one, untested press mold. Great. I needed to do three things, and fast:

1. Get it out of there as undamaged as possible.
2. Affix it back firmly onto the backing tile without using double-sided tape.
3. Figure out why it got so stuck in there in the first place. If it happens now, it'll certainly happen with the porcelain, something we definitely don't want!

To attend to #1, I remembered Barb's advice about using the clay plugs to get the pressed clay out of the mold. So I warmed up some oil clay under a lamp* and gingerly duplicated that technique. With a bit of tugging (oi - it was really in there), I got it out with surprisingly little damage. Practically none. Phew! A thousand thank-yous again, Barb!

[*I heat my clay under a drafting lamp, using the bell of the light to contain the heat.]

Addressing #2 took a bit more doing. The backing tile is slick - glossy slick. This makes is easier for the plaster to be pulled off and for the tile surface to be cleaned in preparation for mold making. It also means that affixing a soft, smooshy clay piece firmly back onto it would be a tricky proposition. I just couldn't squish it on there!

So after thinking about it, I decided to do two things. First, I would smear a thin layer of heated, soft clay onto the backing tile in the rectangle mounting area. Really squish it on there good with a tool, too, then place it under a lamp to keep it soft and sticky.

Then I'd take a BBQ lighter and gently melt the backside of the original, avoiding sag or distortion, just until the backside became glossy and melty. Quickly grabbing the backing tile out from under its lamp sauna, I'd gently press the two together, like those glues you apply to both surfaces before attaching them together. When I actually did it, it worked like a charm. Phew x 2.

As for #3, it was clear the problem was a design flaw. As perpendicular and pothole free I thought the edges were, apparently they weren't. There's some degree of suction between the original, backing tile and plaster, which makes pulling them apart hard enough, but any edge not absolutely perfect has just enough extra grab to be a bigger problem. In short, any minute flaw along the side edge creates an imperfection for rigid plaster to grab.

Now I wanted to avoid the deep bevel the 2010 ornament had because it introduced some annoying problems for pressing. That was why I made the edges of this 2011 ornament straight up and down. After this mishap, however, it's clear that a bevel to some degree was required, if only for mold-making and demolding. Afterward the bevel could be pared down with a blade as a kind of mold flashing, and I suspect a dough blade would be the ticket. We'll see how that goes.

After all was said and done, here it is re-affixed, repaired, and retweaked with a slight outer bevel:

(Right) A new smearing of edging to create the slight bevel and to fill the gap between the bottom of the ornament and the surface of the tile. A gap will suck plaster behind the ornament, creating a "hand" that would tear the piece when pulled out. It doesn't matter if the edges are slightly wavy now, since they'll be cut away in the cleaning stage. (Left) All cleaned up. The glossy areas are parts that needed to be fixed and resmoothed with GooGone. So altogether - phew x 3!

This hiccup caused the loss of half of yesterday, so today will be busier than anticipated. And here I thought I knew just about all I needed to know simply from last year. I mean - how hard could this simple thing be? Ha! I have a sneaking suspicion that this piece has its own lessons to teach me, and trickier ones at that. That's ceramics for you. Let me just say it's a good thing I got an early start this year. 

"Never play a thing the same way twice." ~ Louis Armstrong

Last Sabotages First