The Fish and The Coin

The Fish

These two castings are second generation attempts. The coin is 'pink' foam lost cast in high detail sand, and the fish in a single piece cast in high detail sand directly.






The fish casting did not completely fill the void.  In these two shots I have the casting sitting on top of the original for comparison. This is by far the most detail I have gotten to date, but is also by far the most detailed pattern I have used in casting to date. I have a few theories on why the casting did not complete. These include:

• void inside the pattern positively pressurized enough to slow the flow of metal
• metal was at melting temperature but not pouring temp (1380) so it wasn't as fluid as it should have been
• sand partially collapsed onto the void during the creation of the mold

With some close up shots you can see the kind of defects that can be expected.

 The little holes and pockmarks in the casting can mean a few things. I am theorizing they represent places where moisture was trapped in the casting sand. On contact with the liquid metal this created micro-explosions that damaged the wall of the mold and created these marks.

All in all this piece reestablishes sand casting as a good detailed option for creating parts and pieces. Even though the casting was incomplete, I consider this test a complete success.  

The Coin

The Coin was made from pink insulation foam. Petrobond sand was packed into it's face and placed in a bed of sand.  Metal was poured directly onto the coin and allowed to cool with the back exposed completely to the air.

It's really hard to get the sand to pack directly against the surface of foam completely. This piece is a great example for why we should consider refractory coatings on foam pieces with a lot of detail.

The back of the coin is pretty interesting as it's the first item we've had cool while exposed to the air. You can see the strata that formed during the crystallization of the metal while hardening.

With a little copper wire this becomes a pretty handsome piece of jewelry. Remember, copying is killing the industry.