12. Molding and casting

For this exercise, various molding and casting activities were carried out at different scales.
All molding exercises were intended to be concrete.

01.concrete veneer

For this mold 3D printing was implemented in PLA material and caliber 4mm. several holes were left to make a subsequent fastening with screws and contain the mold.
For the casting, a release material was impregnated, which in this case was vegetable oil, and the concrete mixture was inserted into the mold.

02.Dishes 01

For this mold 3D printing was implemented in PLA material and caliber 4mm. several holes were left to make a subsequent fastening with screws and contain the mold.
For the casting, a release material was impregnated, which in this case was vegetable oil, and the concrete mixture was inserted into the mold.

03.Dishes 02

For this mold 3D printing was implemented in PLA material and caliber 4mm. several holes were left to make a subsequent fastening with screws and contain the mold.
For the casting, a release material was impregnated, which in this case was vegetable oil, and the concrete mixture was inserted into the mold.

Preparation of concrete mixes for pouring

To prepare concrete mixes it is necessary to consider the type of concrete to be implemented, mix well and perform several strength tests.

steps

01. The first step is to prepare the quantities in proportion to the future mold to mix correctly in an industrial mixer.

to be more in matter with the whole subject of molds, the following step consists of pouring the material in some rectangles or buckets of failure. The idea of these is to let them cure and then take them to the failure machine to determine its hardness and resistance to printing.

The molds we used were made and developed also by 3D printer converting the molds made by ourselves as part of the process. Translated with www.DeepL.com/Translator (free version)

Two types of mixes were used throughout the process, one with the traditional concrete method and a second one a little more sustainable by replacing a percentage of cementitious material with ash. This achieved very good results by reducing the amount of cement in the first mix.

04. Buda

Using concrete batching methods, a mold and formwork were designed in conjunction with the university's civil construction department. The idea was to duplicate a "Buddha" of considerable size.

Based on an existing "Buddha" figure, a mold of this figure is made according to the following process:

01

Ease Release™ 205 release agent is applied to the part to be duplicated to ensure a clean release.

02

Using fiberglass, a mold is created that covers the existing piece and this is done at the halves of the figure guaranteeing a point of union and future success in the demolding.

With this base generated by the fiberglass we proceed to use PMC-780 which is a high quality polyurethane rubber that is extremely strong, durable and abrasion resistant. By mixing two parts A with one part B, by weight or volume, PMC-780 urethane pours easily and cures at room temperature, with minimal shrinkage, to become a solid rubber with 80A Shore hardness.

When the two parts of polyurethane rubber and a fiberglass container are obtained to preserve the structure of the form to be made, the concrete mix is prepared. Once the structural strength of the mixture is guaranteed based on the above mentioned tests, the figure is poured into the polyurethane rubber by applying Ease Release™ 205, which is a release agent that was left to cure for a period of three days in an environment of controlled humidity. After reaching the expected hardness, the "Buda" formwork is stripped.