Marinite I

This insulation board is lightweight, non-coroding and does not disintegrate even after water immersion. The oven dried 3R4050, is used in a variety of heat insulating processes, in fire protection and as machined parts. Selections are commonly based on a balance between strength and insulating qualities.


Principal applications : oven walls and linings, welding insulation, fire doors, fire training burn buildings, cable trays, personnel protection, and as insulation for marine ships and off-shore rigs.

Back-up insulation applications : ladles, torpedo cars and tundishes in the iron and steel industry, lime and cement plant rotary kilns, and aluminium die cast holding furnaces.


Technical Data

Density lbs/ft³ (kg/m³) 46 (737)
Modulus of Rupture (Flexural Strength) psi (kg/cm²) 800 (56)
Compressive Strength
Ultimate load psi (kg/cm²) -
@ 5% deformation psi (kg/cm²) 1000 (70)
Moisture Content (normal), % of dry weight 3.0
Thermal Conductivity
Mean Temperature, Btu-in/ft², hr, °F
250°F -
400°F 0.81
600°F 0.79
800°F 0.81
1000°F 0.86
Mean Temperature, (W/m°K)
121°C -
204°C 0.12
316°C 0.11
427°C 0.12
538°C 0.12
Shrinkage 24 hours at 649°C (1200°F)
Linear (Length or width), % 0.4
Shrinkage 24 hours at 649°C (1200°F)
Thickness, % 1.4
Arc Resistance, seconds, ASTM D 495 -
Volume Resistivity, ohm-cm, ASTM D 257 9.7 X (10^7)
Dielectric Strength, m/mil, ASTM D 495 45
Screw Holding Strength
@ 7/8" penetration, lbs (kg) 200 (91)
N.B. The information, details and values indicated are to the best of our knowledge. We recommend to conduct tests according to local conditions. The data is subject to some variations without notice.