Mold Smashing

The molds sat overnight to cool down, but were still piping hot. After hoisting the smaller form out of the sandpit, I rolled her out to the loading dock with the dumpster positioned below- and the restrained smashing began. Xmas smashing- with the investment as wrapping paper. The female figure came out well, with nice dense flashing honeycombing her head and tapering in intensity on down her body. Then it was back to the sandpit for the big fellow who poured with the fire-jet-eruption. He has very little flashing, as the bronze poured so hot it shrank back into itself making a wonderful pocked surface. He came out more intact than I expected. He is missing half his sphere and one arm- I think that area was too turbulent and the gasses won out over the bronze. One of his feet is partially missing as well. They are still full of investment, although I have removed most of it from the surface.

The superheated investment was charred and sulphurous. I have never poured bronze at that extreme of a temperature, and though the wax had burned out completely there was still carbonized wax in the mold. Next time I will only use the inner burners of the kiln, and close the vents down further- I’m certain I was getting a false read on the kiln temps from the outer ring’s heat jumping up the wall and out the vents. This is what compromised the larger form, as it had 4 more inches of girth than the smaller mold- so she burned out fully, and he was just under what he needed.  On a future casting I would like to ensure the molds are fully burned out, then let them chill down further so the molten bronze shocks them harder- and pour the bronze at least 100 degrees cooler.

Then I spent quite awhile putting the foundry back in order.

The figures are both out in my shop now, waiting for me to break out the chasing tools.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s