Entropy Clear Slow Hardener (CLS) is used to extend working properties and cure time when mixed with Entropy Clear Laminating Epoxy Resin (CLR) or Optically Brightened Laminating Epoxy Resin (BRT) for laminating wood, fiberglass, carbon fiber, or Kevlar. These premium resins are used for hand layup, room-temperature processes, or infusion laminating.

This biobased resin system exhibits low color, excellent air release, and exceptional UV and color stability. Use with CLR resin or BRT resin for long pot life and low exotherm lamination and coatings. Resin and hardener combined have a bio-content greater than 30%, and can be modified with epoxy compatible colorants and fillers.

Requires corresponding size of Clear Laminating Epoxy Resin (CLR) or Optically Brightened Laminating Epoxy Resin (BRT - bright white) for use (2:1 mix ratio). See chart below.

Tech Specs

Specifications & Mechanical Data	Entropy CLR/CLS Admixed	Entropy BRT/CLS Admixed
Color	Clear	White
Mix Ratio by Volume	2:1 (resin:hardener)	2:1 (resin:hardener)
Mix Ratio by Weight	100:47 (resin:hardener)	100:47 (resin:hardener)
Mixed Viscosity @ 77°F	800 cPs	800 cPs
Pot Life @ 77°F	43 minutes	43 minutes
Tack-Free Time @ 77°F	8 hours	8 hours
Ideal Working Temperature Range	Optimal - 70-85°F; Extended - 60-95°F	Optimal - 70-85°F; Extended - 60-95°F
Ideal Working Humidity Range	Optimal - 0-40%; Extended - 0-85%	Optimal - 0-40%; Extended - 0-85%
Recommended Full Cure	7 days @ 77°F; post cure recommended	7 days @ 77°F; post cure recommended
Tensile Strength	9,800 psi	9,800 psi
Elongation	6%	6%
Flexural Strength	14,580 psi	14,580 psi
Compression Strength	12,520 psi	12,520 psi
Tg Ultimate	171°F	171°F
Hardness, Shore D	70-80	70-80

Entropy CLR or BRT Laminating Epoxy Resin Quantity	Clear Slow Hardener (CLS) Quantity	Mixed Quantity
32 oz.	16 oz. hardener	48 oz.
1/2 gallon resin	1 qt. hardener	3 qt.
1 gallon resin	1/2 gallon hardener	1.5 gallons
2 gallons resin	1 gallon hardener	3 gallons
5 gallons resin	2.5 gallons hardener	7.5 gallons

Info & Guides

NOTE: Exact fill weight of 5 Gallon CLS Hardener is 5.139 gallons.

Technical Information

Features of Clear Slow Hardener (CLS) Combined with CLR Resin or BRT Resin

Slow hardener for Entropy's high-performance, CLR clear epoxy resin, or bright white BRT epoxy resin.
Green epoxy resin with longer pot life and a slower room temperature cure than CLF (fast) or CLX (Extra Fast) hardeners.
Excellent composite laminating resin ideal for hand layup and vacuum bagging.
Great for high-color applications requiring a clear, non-yellowing resin system.
UV-stable formula with relatively low viscosity.
First USDA BioPreferred Certified liquid epoxy resin system.
CLS requires corresponding size of Entropy CLR Epoxy Resin or BRT Epoxy Resin for use (2:1 mix ratio). See chart below.

Entropy Clear Slow Hardener (CLS)/Clear Laminating Epoxy Resin (CLR) System Best Uses

Surfboards, SUPs (stand up paddleboards), handplanes
Adhesives and sealants
Fiberglass boat repair
Clear coating applications
Natural fiber composites
Carbon fiber composites
Fiberglass composites

Entropy Optically Brightened Laminating Epoxy Resin (BRT)/Clear Slow Hardener System Best Uses

White surfboards
Bright white cosmetic marine laminating applications

Safety and Handling Information

Despite the natural derivation of Entropy resin products, exposure to these materials represents hazards typical of all epoxy resins. Exposure should be minimized and avoided through the use of proper personal protective clothing & equipment, and appropriate manufacturing controls. All persons who use, store, or transport these materials should understand proper handling precautions and recommendations, as stated in the SDS (safety data sheets).

Data Sheets

Clear Laminating Epoxy Resin (CLR) System Tech Data

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CLR/CLS Application Tips

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Optically Brightened Laminating Epoxy Resin (BRT) System Tech Data

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BRT/CLS Application Tips

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