UraGel 751 FR consists of two thin liquids, part (amber) and part B (blue). After mixing, Uragel 751 FR immediately thickens to a buttery non-sag paste, which forms a high strength rigid bond. UraGel 751 FR is especially well suited for bonding cast or pultruded fiberglass parts and surfaces. When fully cured, UraGel 751 FR (Fire Resistant) forms a rigid "fiberglass like" polymer that is easily sanded or machined into final form. UraGel 751 FR can also be used as rigid mother mold back up for flexible molding compounds.

Application and Mix Ratio

Carefully measure out equal parts component A and component B in separate container. Do not mix more than one quart of finished material per batch to insure proper mixing and adequate working time. Pour all of component B into component A and mix by hand with flat spatula. Take care to carefully scrape sides and bottom of container to insure all of both components are include in the mixture. Mixture will change color to a lighter green and thicken to a creamy paste and become slightly warm to touch. Apply thickened mixture to surface.

Once mixed, UraGel 751 FR self-thickens to a gel within one minute and remains trowable for 10 minutes. Full cure is achieved in 24 hours at 72°F.

Parts to be bonded must be absolutely dry and free of any oil film. Degassing can be done with acetone or methyl ethyl ketone, frequently changing wipe cloth. After parts have been thoroughly cleaned, bonding surfaces should be abraded using grinding stone and electric drill. All power created during the abrading using process should be removed by again wiping with acetone or methyl ethyl ketone. After parts have been thoroughly dried (usually about 10 minutes) apply UraGel 751 FR to both surfaces. Press parts together using automatic press or clamps.

The thixotropic (self-thickening) nature of UraGel 751 FR allows for easy application to difficult overhead and vertical surfaces. UraGel 751 FR gives maximum water-weight adhesion when applied to concrete, metal, wood, asphalt or masonry. Styrofoam insulation can easily be bonded to vertical walls and ceilings. UraGel 751 FR contains no solvents or fumes thereby avoiding fire and worker health hazard in contained work environments.


Working Properties

Mix Ratio By Weight

100 parts A/ 88 part B

Mix Ratio By Volume

100 parts A/ 100 parts B

Viscosity @ 72°F (Component A)

450 cps

Viscosity @ 72°F (Component B)

600 cps

Viscosity @ 72°F (Mixed)

500,000 cps


Part A:



Part B:





Working Life @ 72°F

10 minutes

Full Cure Time* @ 72°F

24 hours

*Full Cure time depends on temperature and relative humidity.


Physical Properties

Specific Gravity: (Part A)


Specific Gravity: (Part B)


Specific Gravity: (Mixed)


Weight/Gallon Part A

10.03 lbs.

Weight/Gallon Part B

8.82 lbs.

Weight/Gallon Mixed

9.43 lbs.

Cubic inch per lb. of product

24.49 in3

Hardness @ 72° F

ASTM 2240-85

75 Shore D

Tear Strength

ASTM D-624

900 lb/in

Tensile Strength

ASTM D-412 die C

2750 psi


ASTM D-412 die C



Clean Up

Dispose of all empty UraGel 751 FR component containers in accordance with local, state and federal regulations. Empty component containers can be rendered non-hazardous by rinsing the containers with a small amount of mixed material and allowing material to cure for 24 hours. The containers will then contain non-hazardous cured urethane.

Storage and Shelf Life

UraGel 751 FR is shipped from the factory in sealed containers. The containers should be stored in a cool dry area that is protected from direct sunlight and moisture. Storage temperatures should not exceed 80°F. The shelf life of factory sealed containers stored under these conditions is six months. Containers that have been opened should be resealed immediately after material has been removed in order to prevent solvent evaporation.


Shipping Class: Class 55 Non-hazardous