Dry Cast vs. Wet Cast
In general, pieces that are structural or too large to set in place by hand, like base panels and large sills, work best using the wet cast method. Small, repetitive, non-structural pieces such as copings, bands, small sills, lintels, or ornamental pieces that can be set in place by a mason are generally dry cast. Projects can include any combination of wet or dry cast pieces.
Making Dry Cast Stone
Producing dry Cast Stone begins with making a mold. Molds are built to exact specifications from various materials. They could be made from wood, fiberglass, or rubber. The same mold can be used to produce many pieces for the same job - up to 100 per day from one mold. That ensures that each of these pieces will be identical.
Next is the mixture. We combine fine aggregates with white cement, coloring, and other necessary additives. This is all combined in turbine mixers to ensure a uniform blend. This mixture is then placed in the mold, and then intensely tamped to densely compact the mixture.
Once the piece is ready, we'll remove the mold and examine the piece for quality. If it doesn't meet our standards, we return the piece to the mix and remake the piece. No pieces leave our facility without meeting our standards.
The last production step is placing the tooled piece in a room with 100% humidity to steam cure overnight. The next day it's sanded, washed, and inspected. Once the piece passes inspection, it's marked, wrapped, and palleted for delivery.
Making Wet Cast Stone
The process to make wet Cast Stone is similar to making architectural precast concrete. The main - and critical - difference is the finish. Architectural pre-cast has multiple finishes, whereas Cast Stone focuses on a simulated limestone look. Wet Cast Stone uses much finer aggregates than architectural precast. This produces a texture similar to natural cut stone with minimal surface defects.
Just as with dry cast, the mold is set up first. Once the mold is ready, the first layer of the piece is poured, then vibrated to remove any air. Then reinforcement is added and the second layer is poured. The piece is vibrated again to remove any remaining air, and is then set aside to cure.
The piece is removed from the mold once it's cured, and the mold is set up to produce another identical piece. The final piece is washed and inspected to be certain it meets Edward's standards.
Whether dry cast or wet cast, each piece is individually inspected to ensure that it meets our quality standards and will meet the needs for your architectural project. We do this because we want you to be comfortable specifying Edwards Cast Stone for all your projects.