Slip Casting ~ Disaster

Well, I said it'd been a long time since I did slip casting

and here's the proof!

The plaster mold actually went well but I did not clean the release out of the mold

well enough so it acted as a resist.  

The slip was poured in and left for 15 minutes

 but that was not enough because the slip skin was thin.

Ah well!  Lessons learned.

I'm going to clean out the release, let the mold dry & then try again!

Good thing Mother's Day is a month or more away!

Slip Casting ~

I'm doing some casting again. 

In the past I've experimented with glass casting but have been wanting to return to my "roots" of ceramic casting.  I haven't done slip casting in many years but a long time ago (in what seems like a galaxy far, far, away) I worked exclusively with clay.  Throwing, slab work & slip casting. 

These are good things to know for a glass artist as it's allowed me to make my own molds as well as repair or reproduce molds I like rather than purchasing expensive molds from a dealer.

I was hanging onto a pair of William's first little red boots...sob!

So cute that I just couldn't bring myself to throw them away.

SO....I thought I would make a plaster cast & then slip cast it as a vase!

Mother's day is coming up, right?

A gift to me & my Mommy.

Here's a picture of the first half cast in plaster.  It's coated with Vaseline (used as a release)

& ready for the second pour of plaster.  The boot is coated as well as the plaster.  It's very important to really coat the plaster otherwise the second pour could stick!

This was much more messy than I remembered! 

Yikes!  I need to finish this up this weekend so I can clean the studio get back to production!

Casting Blunder...er BLUNDERS!?!

My mini casting project is progressing albeit minor set-backs. It all started out OK or so I thought (false hope!).

Here's the next 3 small 2"x2" clay positives that I molded out of porcelain clay. I put them all together in one container to a make a larger casting mold...I'm feeling good about this!

Here's the casting mold after it hardened to a "leather hard" firmness. This is the drying state where you still have time to clean-up the edges & image before pre-firing the mold.

Still looking good with less undercuts from last time but a few more bubbles in the mix ~ which results in holes in the mold. I mixed the Master Mold a bit thicker after researching on line that it should be like "thick pudding." Now in hindsight, this was a mistake because I had a hard time removing the bubbles.

OK ~ so I cleaned up the mold, fired it, & then started to pack it with glass. This time I thought I'd try more of the powdered frit instead of the more coarser grind. Stacked it high....hmmm...thinking I'd get thinner discs that would flow into the 2"x2" square. Wishful thinking!

Post-firing. Little, beady, eyes!! Yep, the powdered frit shrunk into small cubes. The mold cracked right down the center, however, everything popped out pretty well so I think I can cast two more eyes.

Here's the four castings so far ~ I think I had beginners luck on the first eye. The other three need coldwork clean-up but they'll look cool incorporated into another larger glass piece.

Casting Tip Sheet

Was going through old emails early this morning & found an email from Bullseye Glass Co. about a new "tip sheet" on casting. How interesting I found it just as I'm working on my small casting samples.

Here's a link if you're interested & want to see how it really should be done!

Casting Experiment ~ The Eye's Have It

Will & I are working with clay. 50 pounds of clay that I've been moving around for a couple of years. I've had plans to make my own molds & to experiment with casting glass. So, instead of working on my year end accounting & 2010 catalog we're playing with the clay!



A few years ago I had wanted to do a whole First Friday show at the gallery around the idea of "Eyes." I love eyes. The symbolism of eyes. The mythology of eyes. The power of eyes. The mystery, the color, shape. Need I go on? Another artist I know poo-pooed my idea until she saw another artist's work sort of related about body parts in an article in Smithsonian....ah-ha...then my idea had validity. Don't you love it when you're right? Not that someone's opinion would stop me from doing what I want too anyway! :)

Here's the start of a small casting project. First make a positive model in clay.

Second, cast it with mold mix. I use "Master Mold Mix." The clay model is secured to the bottom of a small container with soft clay. These are 2" x 2" cubes so I'm just casting them in a small, reinforced, box but for larger castings a frame needs to be built around the model. The mix needs to be thick & creamy so it pours out smoothly & fills in all the small nooks & crannies. After the mix is dry (about 45 minutes on a piece this size) flip it over & remove the soft clay. The mold mix is still soft so there's time to so some addition carving & clean-up. Then it gets fired in a slow firing to dry & harden the mold.

Brush with Bullseye kiln wash ~ three coats in opposite directions. Bullseye shelf primer/wash is made specifically for use with glass ~ not ceramics. When the wash is dry start packing with glass.

Fire slowly to about 1450 degrees, anneal, & slow cool. Don't you love my specific kiln schedule here? Sorry, but firing schedules are boring so I program mine into the computers on my kilns & then adjust them depending on the actual piece going into the kiln. The schedule varies a lot depending on the size & depth of the glass. I keep a kiln journal to document my successes & failures...er," learning opportunities."

Here's the finished piece which turned out OK. It needed more glass to fill the corners but I purposely didn't overfill the mold as I the edges were slightly undercut & I was worried about breaking the mold ~ I was hoping the glass would pop out & I could use the mold again. Unfortunately, the mold cracked & then broke apart. I've since tried to repair it & may try to use it again with blocks around it to contain the glass during the firing. Typically, castings are done in plaster of paris molds that are used one time. The casting needs some coldworking to clean it up & remove any sharp edges.

I have four more little eyes & spirals so I can experiment with more color. This is fun. Maybe it's the beginning of a series?