For Woodstoves & Inserts & Fireplaces & Alternative Fuels & Outdoor Living
🧱 Castable Refractory Cement – High-Heat Masonry Repair & Custom Casting
Versatile, heat-resistant cement for fireboxes, fire pits, and custom forms.
This dry, light brown refractory mix is engineered for extreme heat applications and can be cast into custom shapes, used to fill large masonry voids, or formed into solid stone beds. Once mixed with water, it chemically sets and cures to a rock-hard finish.
🔥 Product Highlights:
- Withstands temperatures up to 2400°F
- 25 lb. tub casts a block 12″ x 12″ x 2-1/2″
- Color: Light brown when cured
- Ideal for:
- Repairing masonry fireboxes
- Casting custom firebrick shapes
- Creating solid beds for stoves or inserts
- Constructing outdoor fire pits
This cement is a go-to solution for DIYers and professionals needing durable, heat-tolerant masonry repair or custom refractory components.
🧱 Castable Refractory Cement – Dry Mix for High-Heat Masonry Applications
Dry mix in tub; light brown when cured.
This versatile, heat-resistant cement is supplied as a dry mix in a tub and cures to a light brown finish. Ideal for casting custom shapes, repairing masonry fireboxes, or forming solid stone beds. Once mixed with water, it chemically sets and dries rock hard.
🔥 Key Specs:
- Withstands temperatures up to 2400°F
- 25 lb. tub casts a block 12″ x 12″ x 2-1/2″
- Suitable for outdoor fire pit construction
- Color: Light brown when cured.
🧱 Castable Refractory Cement – Application Instructions
Ensure proper bonding, curing, and long-term durability by following these steps:
🧼 Surface Preparation
- Clean all surfaces to be cemented—remove dirt, rust, and foreign material
- Chip away loose masonry and debris from cracks or voids
- If using wooden forms or porous backup materials, waterproof them to prevent water absorption from the castable
- Dampen old refractory surfaces lightly with water to prevent them from drawing moisture out of the mix
🧪 Mixing Instructions
- Dry mix contents of the tub for no more than 1 minute to ensure uniformity
- Add 1.5 to 2 quarts of clean water per 25 lbs of dry mix
- Mix thoroughly until the consistency is firm but workable
- If the mix crumbles, it’s too dry
- If it slumps or sags, it’s too wet
- Only mix what can be used within 20–30 minutes, as the cement sets quickly
🧱 Application & Casting
- Apply into cleaned and dampened voids or forms
- Use a trowel or gloved hands to pack and shape the material
- Do not smooth to a slick finish, as this traps moisture
- For casting, ensure molds are waterproof and apply a release agent (e.g., cooking spray)
💧 Curing Tips
- Allow to air cure for 24 hours before exposing to heat
- For best results, mist the surface lightly with water during the first few days to aid curing
- Cover the patched or cast area with plastic or damp cloth to retain moisture and prevent premature drying
- Once cured, the cement is paintable and safe for outdoor use