Saturday, May 14, 2016

SJSU Iron Pour, 2016

This August I will have been teaching at SJSU for 14 years... but in all this time I've never participated in any of our occasional iron pours at our foundry. I've attended a lot of them as a spectator, but I haven't ever had time to contribute a mold. This time, although it was quite last-minute, I put two molds in: one ceramic shell mold, and one sand mold. Neither of them were "art" pieces per se, just things that I could come up with quickly to try out the process. Unfortunately, there was a technical problem with the furnace which prevented the iron from flowing properly and getting hot enough, so the iron "froze" in many molds prematurely. One of my molds suffered from this problem, while the other, ceramic shell mold, split open while being poured. Well, very much a learning process. I'm documenting the process here mostly for my own benefit, so I remember what I did right and wrong when I try this again next year.

A urethane mold I made 21 years ago of a tile from an abandoned train station in Gary, Indiana

The poured wax tile

The wax with gating and pour spout. The air vent is on the back side.

The wax with seven coats of ceramic shell (thanks to Steve Davis for applying most of them.) The plaster beaded up badly and rolled right off the surface. Next time: less silicone mold release on my mold.

I made a quick plywood "flask" in the wood shop.

Two industrial-size egg cartons, discarded by the bakery below my apartment. I sandwiched 1/4" of celluclay (paper maché/ paper pulp) between the two to add thickness, then sanded the edges on the edge sander in our shop. I polyurethaned the crate to protect it from moisture.

The crate in the flask box

I "clayed up" the egg carton, following the part line which was higher on two sides.

I shared a batch of resin-bonded sand with another person, and we used what the foundry refers to as "spanky tools" to ram the sand.

I was late getting back to the Foundry after my class, so one of the volunteers at the Foundry rammed up my second half when he mixed his own. This was a different batch of resin and it behaved diferently.

Many kind helpers helped me pull out the sacrificial egg carton

Steve Davis showed me how to make a pour spout

Pour spout and two air vents

I painted on a solution of graphite in denatured alcohol, then set it on fire to burn off the alcohol.

Nathan Cox demonstrated applying the mold cement.

We closed the mold and used the strapping tool to cinch it together.

My first piece being poured at the iron pour.

The day after the pour: jackhammering out the iron that had seized up in the furnace.

My poor mold, almost untouched by the iron! The iron froze barely an inch past the pour spout. It looks like the last teaspoon of waffle batter poured into a waffle iron... So sad to throw this cool mold straight into the dumpster.

The leaf and berry tile (about 3/5 of its intended length,) and the strange smidgeon of egg carton

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