McGuire Sculpture Studios
Bronze Casting Process


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Patrick McGuire pouring molten bronze into a plaster mold at the foundry.


Beginning with the Greeks in 1500 BC, the process to cast a sculpture in bronze has remained relatively unchanged over the years.

Many of you may have seen a sculptor working in clay create a sculpture, but once the sculpture is completed, the steps required to turn it into bronze require a different art form all its own.

  1. First the sculpture is completed in clay.

  2. The sculpture is covered with a liquid rubber that hardens to make a flexible rubber mold that holds all detail from the original sculpture.

  3. Next the rubber mold is covered in plaster. When the plaster hardens, both the rubber and plaster molds are removed from the clay mold. In many cases, they are cut into several pieces.

  4. With the rubber mold still lying in the plaster mold, hot wax is brushed in the rubber mold. When the wax hardens, it is removed from the rubber mold and is reassemble into the form of the original sculpture.

  5. The wax is checked for any problems which must be corrected before the process can go any further. This is referred to as chasing wax.

  6. The wax sculpture is then cut into pieces no larger than approximately 18" squares.

  7. Sprews and a cup are then applied to each wax pieces. A sprew looks similar to a straw and is attached to the wax pieces so that air can escape when bronze is poured into the slurry molds thus resulting in the bronze reaching the low portions of mold. A cup is attached to the sprew so that the molten bronze can be poured easily into the shells. (See step 10)

  8. Each wax piece is then dipped into a slurry (mixture of sand and plaster) twelve times. Each dip takes 24 hours to dry and harden.

  9. Once the 12th dip has hardened, the plaster shell is heated to high temperatures and the wax is removed. This is referred to as the loss wax process.

  10. The plaster shells are buried in sand with only the top of the cup sticking out.

  11. Bronze is poured into the plaster shells.

  12. Once the bronze has cooled and hardened, the plaster shells are chipped away, thus leaving only the bronze.

  13. All sprews and cups must be cut off.

  14. All remaining bronze pieces are then reassembled and welded back together.

  15. The bronze welds are then ground down.

  16. The reassembled piece is then sandblasted to a smooth finish.

  17. The final step is to patina (or paint) the piece. Acid mixtures are heated with a blow torch and applied to the bronze to add color.

Contact Information

For more information on Patrick McGuire or his artwork, please contact:
McGuire Sculpture Studios
Attention: Natalie McGuire, Art Representative
13811 Starhill Court
Houston, Texas 77077 U.S.A.
281-597-0541 (Monday through Friday, 8:00am to 6:00pm CST)
Electronic Mail
For general information or to place an order:
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Last Updated: 05 Apr 2000 19:37 CDT

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