1. General Installation Principles
Surface Preparation
Ensure the substrate (steel shell, existing refractory, or structural frame) is clean, dry, and free of oil, grease, loose rust, and debris. For steel shells, verify that all studs are welded in place and pass a ring-test for weld integrity before board installation begins. Any surface irregularities that could prevent flat board contact should be addressed.
Layout Planning
Plan board layout to minimize waste cuts. Stagger joints between adjacent boards and between layers -- offset each layer's joints from the previous layer by at least 150 mm. This eliminates direct heat leakage paths through continuous joints. Mark cutting lines clearly on the board surface before cutting.
Expansion Joints
Leave expansion gaps as recommended for the operating temperature. For applications above 800°C, allow 2–3 mm per linear meter of board length. Pack expansion joints with ceramic fiber blanket or compressible refractory felt -- do not fill with rigid material which would defeat the purpose of the joint.
2. Board Cutting & Shaping
Tool Selection
Use carbide-tipped circular saws for straight cuts. Jigsaws with carbide blades handle curved cuts and cut-outs. Band saws are ideal for workshop preparation of complex profiles. For boards up to 25 mm thick, score-and-snap with a heavy-duty utility knife and straight edge works for straight cuts.
Cutting Technique
Support the full board on a flat work surface. For circular saw cuts, set blade depth to just exceed board thickness. Feed rate: moderate and steady -- forcing the cut can cause edge chipping. For jigsaw work, use a fine-tooth carbide blade and reduce orbital action to minimize edge breakout.
Drilling & Shaping
Holes for pipe penetrations and anchor bolts are drilled with standard twist drills or carbide-tipped hole saws. Pre-drill holes slightly larger (1–2 mm) than the stud or bolt diameter to prevent cracking during installation. For complex shapes, CNC machining with carbide tooling produces the cleanest results. Manual routing with carbide bits works for field adjustments.
3. Fixing Methods & Accessories
Mechanical Fixing with Stainless Steel Studs & Washers
This is the standard method for furnace and kiln backup insulation. Stainless steel (304 or 316 grade) studs are welded to the steel shell on a grid pattern. Boards are impaled over studs through pre-drilled holes. Stainless steel washers (minimum 40 mm diameter) and nuts are then applied. Torque specification: hand-tight plus quarter-turn -- over-torquing crushes the board and creates a thermal short circuit. For horizontal (overhead) installations, use self-locking nuts or tack-weld the nut to the stud.
Adhesive Bonding
High-temperature inorganic adhesive (sodium silicate or phosphate-bonded) can be used alone or in combination with mechanical fasteners. Apply in a continuous bead around the board perimeter plus diagonal cross-beads across the face. For vertical walls, adhesive alone may suffice for boards up to 25 mm thick. For thicker boards, overhead installations, or applications with vibration (e.g., ladles, transfer cars), always use adhesive plus mechanical fasteners. Follow adhesive manufacturer's curing schedule before exposing to heat.
4. Joint Treatment
Single-Layer Installations
Butt boards tightly together. Fill any gaps exceeding 2 mm with compatible high-temperature sealant or ceramic fiber paste. Pay particular attention to corners, penetrations, and transitions where heat leakage is most likely.
Multi-Layer Installations
Fill and seal joints in each layer before applying the next. The joints of each successive layer must be staggered from the layer below by at least 150 mm. This staggered pattern is critical -- aligned joints create a direct thermal short circuit through the entire insulation system.
5. Weather Jacket & Protective Cladding
Calcium silicate insulation tolerates occasional moisture but is not waterproof. All outdoor installations and any indoor installation exposed to water spray, wash-down, or condensation require a weather barrier.
| Jacket Material | Typical Thickness | Application |
|---|---|---|
| Aluminum (3003 or 5052 alloy) | 0.5–0.8 mm | General outdoor service. Corrosion-resistant. Formable on site with hand tools. |
| Stainless Steel (304 or 316) | 0.4–0.6 mm | Chemical plant, food grade, marine, or where aluminum is prohibited. 316 grade for coastal/chloride exposure. |
| Galvanized Steel | 0.5–0.8 mm | Economical option for dry or low-corrosion environments. Not recommended for chemical or coastal exposure. |
| PVC / GRP | 1.0–2.0 mm | Low-temperature service (below 80°C). Chemical resistance. Not suitable near hot surfaces. |
| Mastic / Vapor Barrier Coating | 2–3 mm applied | Secondary vapor barrier under metal jacket for cold/cryogenic service. Prevents condensation within the insulation. |
6. Safety Precautions
Important Safety Notice
Calcium silicate board contains synthetic mineral fibers and crystalline silica. While Mingfa products are 100% asbestos-free and have never contained asbestos, the dust generated during cutting can be an inhalation irritant. Follow these precautions and all site-specific safety regulations.
Respiratory Protection
Wear a minimum N95 (or FFP2) dust mask during all cutting, drilling, grinding, or sanding operations. In confined spaces or during prolonged cutting, use P100 (FFP3) respirators with local exhaust ventilation. These are standard industrial hygiene precautions applicable to all mineral-based insulation boards.
Eye & Skin Protection
Safety glasses or goggles during cutting and drilling. Cut-resistant gloves when handling boards -- edges can be sharp. Long sleeves and pants to minimize skin contact with dust. Wash exposed skin with soap and water after work. Do not use compressed air to blow dust off skin or clothing -- it aerosolizes fine particles.
Work Area Controls
Cut in well-ventilated areas. Use dust collection attachments on power saws where available. Wet-cutting methods reduce airborne dust. Vacuum clean-up preferred over dry sweeping. Dispose of cutting waste in sealed bags or covered containers per local regulations.
Material Handling & Storage
Store boards flat on pallets in dry, covered conditions. Protect from rain, snow, and standing water before installation. Boards that have become saturated with water must be fully dried before installation -- wet calcium silicate has reduced insulation value and can cause steam pressure damage during heat-up. Lift boards from pallets; do not slide across edges which causes corner damage.
Adhesive & Sealant Safety
Inorganic high-temperature adhesives and sealants may be alkaline (pH 10–12). Avoid skin and eye contact. Wear chemical-resistant gloves when applying. Ensure adequate ventilation during curing as water vapor is released. Follow the specific instructions on each product's Safety Data Sheet (SDS).