All Jesmonite products including Jesmonite AC100 are classed as porous and would need to be sealed with a top coat sealer to achieve a waterproof surface.
Jesmonite AC100 is an Acrylic Modified Gypsum Composite compared to Jesmonite AC730 which is an Acrylic Modified Cementitious Composite. Jesmonite AC100 contains gypsum and is designed to replicate very fine surface detail and Jesmonite AC730 contains decorative aggregates and is designed to replicate concrete and stone surfaces.
https://www.youtube.com/watch?v=al40TXLQG2o
For casting Jesmonite AC730, every 1,000ml of mould volume will require 1,850g of complete mixed Jesmonite AC730 (1,850g Jesmonite AC730= 1000ml).
You can use this Jesmonite Calculator by RazzoStudio.
Jesmonite AC730 cured surfaces can be sanded using a variety of sandpaper grades to reveal decorative aggregates and achieve a range of different surface appearances and textures. Most users will start with a coarse sandpaper and then move onto a fine sandpaper grade for finer finishing. The sanding process can be done by hand or with a power sander.
The most appropriate Jesmonite material for a decorative splash is Jesmonite AC730. Jesmonite AC730 achieves an A2-s1-d0 EN13501-1 (non-combustible) Fire Classification.
Jesmonite Flexiguard Sealer is the most appropriate Jesmonite sealer for Jesmonite AC730 surfaces. The Jesmonite Flexiguard Sealer is a solvent-free, nano based technology. This sealer is designed for stain resistance and offers an invisible surface effect. The Jesmonite Flexiguard Sealer achieves a protective layer less than 100-nm thick which bonds with the inner pores of the AC730 substrate.
Jesmonite AC730 can be used for water features and within wet environments.