Lost Wax Bronze Casting

An illustrated review of our lost wax bronze casting process.

First we modeled the pieces we wanted to cast out of modeling wax.  The wax becomes malleable when heated - we heated metal tools over an open flame and applied to wax.  We each cast three pieces.  My goal was to make a pair of earrings.  The form is that of a samara (the fruiting structure of a maple tree, shown with the modeled wax above).

A mold is constructed for each of the wax forms.  In this process we create a plaster mold in a tin can.  A metal rod is inserted in the bottom of our wax form and into a mound of clay.  The clay mound will become the well for the wax to melt.  Then the form is coated with a thin coat of plaster to insure the fine details are preserved. 

Surround form with can and seal with modeling clay.  Fill form with plaster.  Allow plaster to set about an hour.

Turn over dried mold.  Remove clay mound.

Use pliers to remove rod.  The mold is allowed to fully dry (about 4 days).  Then the molds are fired in an electric kiln, I think to cone 4, and the wax melts out of the form.

The mold is removed from the kiln when it has cooled to about 200 degrees.  The mold is inserted into this tub of sand to keep it stable while heating.  A couple of bronze nuggets are placed into the well and heated with the blow torch until they begin to bubble.

Bronze nuggets.

Once the bronze turns liquid heat is removed and the top of the mold is plunged to force the bronze down into the mold.  The bronze and mold is then allowed to cool.

Cooling bronze.

The process is very time sensitive, everyone in the class had a different job they were responsible for.  Two casting stations were set up.  About 40 molds were cast in 2 hours.

Cooled molds.

Bronze nuggets.

Once the forms are cooled you knock out the plaster mold.  Because bronze is much stronger than the plaster there is no danger in damaging the bronze form while destroying the plaster around it. 

Only one form was successfully cast out of three.  I guess no earrings!  Bronze castings are always a risky venture.  Sometimes the bronze only partially fills the form if not properly plunged.  1 out of 3 seemed to be the class average... to finish the piece you scrub off the remaining plaster, and I would have sawed off the stem I added at the top to cast the form and drilled a small hole to attach to the earring.  This was a really interesting process... despite the poor results.  It amazes me that an artist could invest so much with such risk of failure.  I guess the same could be said of ceramics...

10 Bowls + 10 Cylinders

This assignment in ceramics builds on the first two assignments we had (10 cylinders, 10 bowls).  It differs in that of the 10 bowls half had to be identical and all of the 10 cylinders required handles.

We worked with a porcelaneous stoneware, which has this incredibly white body when fired.  Pretty nice to throw with as well - smooth, and it stands pretty well.  First I tackled the mugs.  I made several along a theme for the Bardens.  I was really pleased with the handles (maybe I finally mastered this!) and overall I felt they were well formed, concise, light pieces.

I decided to really raise the bar on my bowls project by attempting to throw large pieces.  There is definitely a learning curve in mastering this process.  The key to my success was using my sponge when pulling up the walls.  Each bowl was thrown using 5-6 lbs. of clay.  Really excited about these large forms!

I made 5 bowls with this form.  They are about 12-13" in diameter.

I really tried to branch out and push the basic bowl form with these remaining pieces... lots of experimentation here.  These are all wheel thrown forms that have been manipulated in one way or another.  I really like where some of these are going... I wonder why it took me so long to make this kind of work?  I suppose I was scared of 'messing up' a form by playing with it after it was thrown.  After consistently throwing those first 5 pieces it gave me confidence to branch out, knowing that if I messed up I could always just throw it again.  

Anyway, check out this new line of work!

I really like this form.  I was so upset when it cracked in the bisque firing!  I'll have to make another.

Cutting the forms, then distorting them.

This is a favorite among the pieces.

The distortion here is cutting holes, then carving the design, which is topography and a mountain lake.

Denim Bag

I don't know when I found the time to make this bag.  The truth is sometimes you get an idea in your head and it itches so bad you do whatever you have to make it.  It all started when I saw the pattern for this bag on Design Sponge, and of course all I could do was think about how I would do it  differently. 

What I really liked about it was the way these top flaps were interacting with the strap.  I expanded on that idea with some remnant denim I had from a previous project.  All these materials are remnants!  Always nice to be able to jump into a project without leaving the house or spending money.

This is my final sketch for the bag.  As you can see in the following photos, I managed to cut the front flap pattern piece backwards, so it joins the side seams on the right instead of the left.  Also, I ran out of denim and so I used the lining fabric instead to create the piece that wraps under the bag. 

So, what's new and different about this bag?  I've never used button holes in my bags and some experimentation was involved with figuring out how to best accomplish those.  Also, I used the same stitch setting to etch out my 'C TJ C' logo on one of the front flaps.  This bag also features a magnetic snap center closure.  And at the last minute I added these crazy patchwork details on the piece that wraps under the bag.  I'm still not sure if I love them or hate this detail... jury is still out.

How could this bag be better?  Well, my main criticism is that it is just too floppy - that is to say I wish it held up its shape better.  I really thought the denim would provide that body and structure... no such luck.  I think the key is in the lining fabric.  Using the heftier faux suede on the landscape bag was more successful.  I just feel like when carrying the bag around the aesthetic composition of the bag is lost, especially with the flap interest.

Functionally, this bag is pretty good.  I was scared when drawing the pattern that it would be too big for daily use, but it is quite a nice size.  It doesn't hold more than you want to cary:).  Many pockets... but I think I would say that there are too many (9, 3 inside, then 3 on each front) that are all about the same size... it might be better if there was more variation.  I also added a center divider to the interior of the bag that I now just find annoying.  Won't add that feature again.  I also made the strap adjustable, so that it can be worn across your body or on the shoulder. 

What do ya'll think?

 

Glazed Ware

Glazing is continually a struggle for me.  But I'm beginning to develop an eye for what to look for in glazes, and I'm slowly figuring out what it is I like.  It is a slow process, but I'm getting there.  I think ultimately I'd like to just identify 4 or 5 glazes that would become my aesthetic and signature.  Maybe then glazing wouldn't be such a guessing game.

To begin the semester I thought it was sound to just go through and have a sample of all the glazes in the lab.  So each of my small bowls, with trimmed feet, is glazed a different color.  All these were fired to cone 10 reduction (removing oxygen in kiln for part of the firing).  This is also the first claybody we were working with... more recent pieces I've thrown have a whiter, more porcelain-like color, which does effect the glaze slightly.

From left to right:  Orange Matte, Ocean Green, Cannon Ball Blue

Top row, left to right:  Reitz Green, Tomato Red and Jade Celadon, Bernie's Satin Matte

Bottom row, left to right:  Tea Dust, Sana's Green, and Temple White

First pair:  Ocean Green.  This is a cone 6 glaze I made last semester, it behave differently in cone 10 reduction (as it is purplish blue rather than green).  I think I like it more here.

Second pair:  Antique Green and Barium Copper.  Antique Green is used on the inside and majority of the outside of the cup.  Just the bottom inch or so on the outside is dipped in the Barium Copper (because this is a toxic glaze and should not be used on the interior of a vessel you eat from).  I really like the subtleness of these colors.  I actually like all these cups!

Turquoise Oribe, Jade Celadon, and Blue Celadon

Each of these examples has white slip decoration beneath the glaze, which adds slight contrast to the darker claybody.  The cup with the blue celadon also had copper carbonate oxide rubbed to accent the design - and it went pink with the glaze!