Temperature/Dry/Cure

Fabrication of XS Precast Mix should be inside a shop. Casting should take place when shop temperature and all materials are maintained between 50°F (10°C) and 90°F (32°C) throughout all fabrication and curing.

Product will dry and cure slower at cool temperatures and conversely, faster at warm temperatures. Full cure is reached at approximately 30 days, like concrete. Although rare, at high altitudes and dry climates, some pieces may require covering with plastic to slow the cure and avoid curling.

Mixing

Single Bag Batches

1. Utilize a handheld concrete mixer with a helical (spiral) mixer blade, such as an Collomix Xo-55 Dual Shaft Mixer or similar.
2. Thoroughly mix XS Precast Modifier.
3. Add 1 gal (3.8 L) XS Precast Modifier to a clean 5 gal (18.9 L) pail or similar mixing vessel.
4. Add Color Packs to XS Precast Modifier (if desired) and mix.
5. While mixing add approximately ¾ of the XS Precast Mix bag.
6. Continue mixing until all dry powder is incorporated.
7. Scrape sides of pail with margin trowel to prevent dry pockets from forming.
8. Add 16 oz (0.5 L) water, mix into a looser consistency.
9. Add remaining XS Precast Mix and continue to mix for 2 – 3 minutes.
10. Up to an additional 16 oz (0.5 L) water may be added for a more fluid mix.
11. With multiple single bag mixes, where color match is of concern, box multiple pails.

Multiple Bag Batches

1. Utilize a mortar mixer (preferred with a horizontal helical [spiral] shaft) or a concrete mixer of sufficient size to allow the free vertical fall of product while mixing.
2. Maintain the ratio of 1 gal (3.8 L) XS Precast Modifier to 1 - 50 lb (22.7 kg) bag XS Precast Mix.
3. Thoroughly mix XS Precast Modifier.
4. Place total amount of XS Precast Modifier for the entire mix into the mixer.
5. Add all Color Packs to the modifier (if desired) and start mixer.
6. Slowly add one XS Precast bag at a time to the mixer to prevent material from forming dry fiber pockets.
7. Additional water may be added, not to exceed 16 oz. (0.5 L)per bag of XS Precast Mix
8. After last bag is added, allow all material to thoroughly mix for 2 – 3 minutes. Visually inspect entire load to ensure that all fiber is blended.

Application

Although not limited to it, the most common method of placement simply involves pouring XS Precast Mix directly from the pail or mixing vessel into the form or mold.

Demold

In warm weather 4-6 hours may be appropriate to de-mold. Cool temperature or pieces with extreme texture will require overnight drying. XS Precast Mix should not be left in the mold past a 24 hour period, as curling of the piece is likely. A freshly de-molded sample should be handled similar to granite or natural stone, and should be well supported above the work surface to allow the free flow of air around the piece.

Cleaning

All XS Precast Mix samples require cleaning, except those that are to be polished. SCR diluted with water 3:1 (3 parts water to 1 part SCR) is recommended.

For specific directions on SCR refer to its TDS.

Slurry

XS Slurry fills pin holes and voids to create a smooth surface. For specific directions on XS Precast Slurry refer to its TDS.

Grind/Polish

If additional decorative aggregate was added to the XS Precast Mix or if the desired appearance demands it, the product may successfully be polished.

1. Grind casting sample as soon as practical. Allow a minimum of 8 hours cure time.
2. When decorative aggregate is added, begin wet grinding with 50 grit diamond pad to expose aggregate. This step may be skipped if no decorative aggregate was added.
3. Proceed to wet grind with 100 grit diamond pad.
4. LD1800 may be utilized with wet 100 grit grind to densify and fill pinholes with resultant color match slurry. For specific directions on LD1800 refer to its TDS.
5. Allow LD1800 and slurry to dry. Proceed with 200 grit and if any pinholes are still present add more LD1800 and continue grinding.
6. Remove any excess dried slurry with the 200 grit.
7. Proceed through 400 grit polish. If stain and / or sealer is to be used do not polish past 400 grit, as a measure of profile must be maintained for stain penetration and sealer adhesion.
8. If desired and sealer is not used, one can continue polishing through 800 grit and beyond, however, such a piece is subject to staining.

Staining

XS Precast Mix accepts most concrete stains. Eco-Stain adds a desirable design element to any XS Precast Mix piece and is eco-friendly and UV stable. Staining customarily follows slurry. For specific directions on Eco-Stain refer to its TDS.

Sealing

XS Precast Mix pieces are completed by sealing. Two distinct sealers have been created for XS Precast Mix:

• XS-327 - hybrid water based polyurethane available in matte and gloss finish.
• XS-PC12 - hybrid solvent based polyurea, color enhancing, high gloss mirror finish.

For specific directions on sealing refer to the appropriate TDS.

Seaming/Adhesion

100% silicone caulk provides an excellent seaming and adhesive fastening material, as it allows for movement of the precast piece. XS Precast Mix like any other concrete will undergo slight dimensional variations based upon its environment (e.g. shrinkage or expansion).

Do not use caulking or adhesive that could “bleed” through the finished surface, such as petroleum based products. Large pieces and under-mount sinks will require mechanical fastening.

Suitability Sample

Always prepare an adequate number of test samples for suitability for products’ intended use.

Clean Up

Before XS Precast Mix dries; spills and tools can be cleaned up with water.

Disposal

Contact your local government household hazardous waste coordinator for information on disposal of unused product.