So last weekend we tried to cast our two sculptures. The mold and everything went great except for the actual casting (by the way it looked terrible). So what went wrong? Since last week I have done some research on bronze casting defects. We had a lot of oxidation going on as well as very rough surface textures.
 |
| The casting defects of my chameleon sculpture. A lot of bad oxidation and a sandpaper like texture. Also note the huge sprue at the back (not good). |
The oxidation (large bubbles covering the entire sculpture) was due to the fact that we decided not to put any coal over our bronze, in other words we didn't add anything to de-oxidize our molten metal. Our gating system can probably be the blame for the rough texture.
I've done some research on effective gating sytems, I think the gating system that I've made for this weekend will be a lot better but still not entirely 100% yet. For the next attempt I would like to modify the pouring-cup a bit. I would like to give it a pouring basin for more smooth pours and to act as a way to filter any dirt. My sprue (below the pouring-cup) now go gradually thinner towards the bottom and will now act as a bronze reservoir so that the bronze will enter the mold consistently and without any pauses that could have cased the bronze to freeze.
Here is the gating system for my next attempt.
 |
| A simple sculpture of a goat. The new gating system looks a lot more promising but still not there yet. |
 |
| A close-up showing the detail on the wax sculpture. |
Comments
Post a Comment