1401-21T / 4101-21

Thixotropic Epoxy System for Hand Layup – 

Multifunctional epoxy and cycloaliphatic-amine blend hardener for high performance composite parts. Thixotropic 1401-21“T” resin helps to prevent drainage in laminate on vertical surfaces. Two curing agents (4101-21 fast and 4101-21 slow) provide a complete range of working times from 40 minutes to 6 hours, and by blending the curing agents, any point in between. 

_images/medium/12231146351401-21T - 4101-21 380x308 template.jpg


Rhino 1401-21T with 4101-21 provides for ample pot life with fast cure development at standard process temperatures. Rhino 1401-21T also provides good thermal resistance, excellent fatigue and inter-laminar shear strength with rapid wetting of E-glass fiber reinforcements. Rhino 1401-21T Epoxy Resin is formulated for highly increased E-glass fiber compatibility with zero VOCs and 100% solids.

Suggested Uses

Hand Lay-Up of fiberglass reinforced parts and tooling.

System Liquid Properties

System Liquid Properties1401-21T / 4101-21
Viscosity 1401-21 Resin, 77°F:2,300 - 2,700 cps (thixotropic)
Viscosity 4101-21 Slow Hardener, 77°F:20 cps
Viscosity of 4101-21 Fast Hardener:50 cps
Mix Ratio, Resin to Hardener:100:30 by weight
Weight Per Gallon, 1401-21 Resin:9.5 - 9.6 lbs
Weight Per Gallon, 4101-21 Hardener:7.9 - 8.1 lbs
Weight Per Gallon, Mixed:9.2 lbs
Mixed Viscosity, 77°F:350 - 550 CPS (thixotropic)

Gel Time Recipe Table

Rhino 1401-21 Resin, 100 parts / Rhino 4101-21 (all), 30 parts:


Get Time, 150 grams at 77°FPercent of 4101-21 SlowPercent of 4101-21 Fast
360 minutes100%  (30PHR)-
240 minutes90%  (27PHR)10%  (3PHR)
100 minutes75%  (23PHR)25%  (7PHR)
70 minutes60%  (18PHR)40%  (12PHR)
40 minutes-100%  (30PHR)

Resin Mixing Basics

Condition epoxy resin and hardener to between 20ºC and 35ºC (68ºF to 95ºF) to ensure proper mixed viscosity. Introduce mixed material onto part or reinforcement(s). Curing temperature(s) between 40ºC and 65ºC (104ºF to 149ºF). Hold at this temperature for between 4 and 6 hours. Cure temperatures may be from 50°C to 85°C to accomplish maximum HDT. Optimum cure time(s) versus temperature(s) will depend on parameters such as part thickness or size.

Reinforcement Types

Rhino 1401-21T Epoxy Resin is specially formulated for compatibility with E-glass and carbon fiber reinforcements.

Advantages of Rhino 1401-21 Epoxy Resin

Due to the highly thixotropic nature of 1401-21T epoxy resin, it is possible to laminate thick sections without vertical drainage of the epoxy resin. Rhino 1401-21T Epoxy Resin is formulated to improve the intimate bond between the epoxy resin and E-glass or carbon fiber reinforcements. This formulation technique results in increased physical properties as follows:


• Fiber Pull-Out Strength• Tensile Strength and Modulus
• Flexural Strength and Modulus• Compressive Strength
• Impact Resistance• Inter-Laminar Shear Strength


Of equal, if not greater significance is the retention of the above properties after exposure to heat, cycle fatigue, water, expected adverse environmental reagents such as salt spray, acid rain, etc. The formulation of 1401-21T Epoxy Resin results in minimal degradation of the cured composite’s physical properties as compared to epoxy resin systems not containing the proprietary formulation constituents of 1401-21T Epoxy Resin. The benefit to the composite fabricator is obvious and clear: Increased product life and confidence!

Cured Physical Properties of Composite

A-260 unidirectional E-glass (epoxy compatible rovings) with Rhino 1401-21T Epoxy Resin and 4101-21 Epoxy Hardener (70:30 glass to resin ratio). Cure schedule - 2 hrs at 35ºC (infusion) / 4 hrs at 65ºC (basic cure) / 2 hours at 85ºC (final cure).


PropertyResultTest Method
Tensile Strength:83,000 psiASTM D-638
Tensile Modulus:5,250,000 psiASTM D-638
90° Tensile Strength:6.05 ksiASTM D-3039
In-Plane Shear Strength (4 plies + 45°)9.14 ksiASTM D-3518
Flexural Strength:86,000ASTM D-790
Flexural Modulus:2,490,000 psiASTM D-790
Izod Impact:44.5 ft/lb/inASTM D-256-A
Water Absorption:0.09%ASTM D-570
Barcol Hardness:64-

Cured Physical Properties of Neat Resin

Rhino 1401T-21 Epoxy Resin, 100 parts, Rhino 4101-21 Epoxy Hardener, 30 parts. Cured 2 hrs at 35ºC (infusion) + 4 hrs at 65ºC (basic cure).


PropertyResultTest Method
Tg (DSC):194°F (90°C)IPC-TM-650, 2.4 - 2.5
Shore D Hardness:90DRhino
Tensile Strength:10.30 ksiASTM D-638
Ultimate Elongation:7.4 - 7.5%ASTM D-638
Tensile Modulus:465 ksiASTM D-638
Ultimate Compressive Strength14,500 psiSandia Labs Method
Flexural Strength:18.65 ksiASTM D-790
Flexural Modulus:430 ksiASTM D-790

How Supplied

Rhino 1401-21T/4101-21: Supplied in 5 Gallon Pails, 55 Gallon Drums and 250 Gal IBC’s.


Rhino Equipment
Civil Engineering
Resins - 908 - 1315
Resins - 1316 - 1409
Specialty Products