Marinite® Calcium Silicate Insulation
— Grades, Specs, and What Comes Next

Marinite is a structural calcium silicate insulation board developed for high-temperature industrial applications. It is non-asbestos, non-combustible, and machinable — it can be cut, drilled, and fabricated with standard woodworking tools. Marinite boards are rated ASTM E84 Flame 0 / Smoke 0, and most grades carry published electrical insulation data, making them a common specification for enclosures and electrical housings operating at elevated temperatures.

Marinite is a calcium silicate board — a composite of calcium, silica, and reinforcing fibers, formed into rigid boards under heat and pressure. It contains no asbestos and no gypsum. The result is a dimensionally stable board that maintains structural integrity and insulating performance at temperatures up to 1500°F, depending on grade.

Marinite is used across industrial and commercial applications wherever non-combustible structural insulation is required. Common applications include fire door cores and assemblies, oven and kiln housings, furnace wall liners, welding and torch protection panels, marine fire insulation, electrical enclosures, and aerospace ground support equipment.

AWMCO stocks five Marinite grades sourced from BNZ Materials. All are final, non-restocking inventory — when current stock is sold, it will not be replenished.

BNZ Materials, the sole manufacturer of the Marinite product line, has permanently ceased its Marinite production operations. There is no alternative manufacturer of Marinite — the brand is discontinued. Buyers who have historically sourced Marinite from BNZ distributors or directly are now competing for a finite pool of remaining inventory.

When AWMCO's remaining BNZ inventory sells through, Marinite will no longer be available from any source. Buyers who need ongoing supply of calcium silicate board in the same density and temperature range will need to qualify a replacement product. AWMCO recommends Super Firetemp as the primary ongoing alternative — it is stocked monthly and covers most Marinite application requirements.

AWMCO cannot guarantee how long current Marinite inventory will last. Demand has increased significantly since BNZ's production facility closure announcement. Buyers who have immediate or near-term project requirements should order now. For long-term or recurring supply, transitioning to Super Firetemp or another calcium silicate insulation is strongly recommended.

AWMCO is currently working to publish detailed specification comparisons for each Marinite grade against its closest Super Firetemp equivalent.