Acrylic food-safe sealer is probably the best.
QUIKRETE® Countertop Mix is a product specially formulated for casting defect-free countertops. It contains a high range water reducing agent, which makes water optimization difficult for users without experience with this type of mixture. Slight variations in bag weights can influence the water demand. We recommend against adding flow enhancers to this mixture, as the combination effect with the existing water reducing agent will yield unpredictable results, which may include excessive air entrainment, compromised compressive strength, or extensive shrinkage cracking.
QUIKRETE® Countertop Mix is a neutral gray when cured. QUIKRETE® Countertop Mix – Tint Base is a very slight off-white when cured.
The minimum thickness for QUIKRETE® Countertop Mix is 1-1/2”, but there is no maximum thickness. Please keep in mind that countertops weigh approximately 130 pounds per square foot for each inch in thickness.
QUIKRETE® Countertop Mix is available in standard gray (1106-80) and as a light colored tint-base (1106-81) for use with QUIKRETE® Liquid Colors. Add QUIKRETE® Liquid Cement Color or QUIKRETE® Stucco & Mortar Color directly to the mixing water, following the directions on the bottle. QUIKRETE® Liquid Cement Color is available in red, brown, buff, charcoal and terra cotta.
Steel reinforcement may be necessary, depending on the performance expected (ie. Cantilevers, spans, etc.) We recommend contacting the Concrete Countertop Institute online for design assistance.
We recommend using an unsanded tile grout made by Custom Building Products for your application. Available in a variety of colors, so color matching will be easier, product information can be found at https://www.custombuildingproducts.com/support/interactive-tools/grout-color-choices.aspx
QUIKRETE® Countertop Mix is a current, active product. You can contact your local Quikrete plant to determine availability in your area. Your closest plant can be found at the following website: https://www.quikrete.com/onthejob/locations.asp
Please call or visit your local Home Depot store to discuss availability of 80 lb QUIKRETE® Countertop Mix – Tint Base (No. 1106-81). If QUIKRETE® Countertop Mix – Tint Base is not a regularly stocked item at your local Home Depot store, they should be able to special order it for you. Please note that QUIKRETE® Countertop Mix – Tint Base will not achieve a pure white appearance due to the aggregate in the product.
QUIKRETE® Commercial Grade Countertop Mix is not suitable for your application; instead, we recommend using QUIKRETE® Polymer Modified Structural Repair or QUIKRETE® Quick Setting Cement for this project. Both of these products can be sculpted while setting to match the existing contours of the wall, and can be applied without the need for forming.