Slow Hardener

5:1 Slow Hardener


Slow Hardener is a low-viscosity epoxy curing agent for use with 5:1 Epoxy Resin. Extends working time and slows curing time in warmer temperature conditions. Not intended for clear coating applications.

Note: 5:1 Slow hardener is also available in a 10.4 gallon container for use with drums of resin. Please contact us for pricing.

SKU: N/A Category:


  • In warmer temperatures (maximum 95°F), the 5:1 Epoxy Resin/Slow Hardener mixture remains workable longer, extending application time
  • Cures to a moisture-resistant, high-strength, light amber finish when mixed with TotalBoat 5:1 Epoxy Resin
  • Viscosity is preferred for ease in wetting out fiberglass and other fabrics
  • Makes a strong filleting or fairing compound, or adhesive when combined with 5:1 Epoxy Resin and various thickening agents
  • Excellent thin-film characteristics provide smooth flow-out and self-leveling ideal for coating and laminating
  • Easy to measure and mix using pre-calibrated 5:1 Epoxy Pumps (sold separately), or, if preferred, by weight or volume
  • Compatibility: TotalBoat 5:1 hardeners can be used interchangeably with other traditional 5:1 marine epoxy systems
  • Sizes: Size A 6 fl. oz., Size B 25 fl. oz., and Size C 127 fl. oz. Note: Hardener sizes correspond to sizes of TotalBoat 5:1 Epoxy Resin
  • 5:1 Slow Hardener is also available in a 10.4 gallon container, for use with drums of 5:1 resin. Please contact us for pricing

Stays workable longer so you have more time to get the job done

TotalBoat 5:1 Slow Hardener buys you a little more working time in warmer temperatures that tend to reduce working time and speed cure time of epoxy resins. You get a little more time to apply it because it won’t kick as fast. To get started, measure the mix of epoxy resin and hardener precisely, which is easy to do–especially with the pre-calibrated 5:1 Epoxy Pumps (sold separately). Combine 5:1 Slow Hardener with 5:1 Epoxy Resin in a five-part resin to one-part hardener ratio. Then spend about two minutes mixing thoroughly. The epoxy resin/hardener mixture can be used for wetting out fiberglass and other fabrics, coating, and bonding. The cured result is exceptionally strong and very moisture resistant.

Note: Epoxy pumps may not be compatible between brands. If using TotalBoat 5:1 Fast Hardener with a different brand of traditional 5:1 marine epoxy resin, be sure to confirm accurate mixing ratios based on the exact quantity each pump will yield. For best results, use either the TotalBoat Epoxy Pumps in the resin and hardener or the other brand’s pumps.

5:1 Slow Hardener Specifications

  • Mix ratio by volume: 5 parts epoxy resin to 1 part hardener
  • Application temperature (5:1 Epoxy Resin and Slow Hardener): ~ 70-95°F
  • Minimum recommended temperature: 60°F
  • Recommended temperature for dispensing via pump: 60-70°F
  • Pot life @ 75°F: 20 minutes
  • Set time @ 75°F (thin film): 10 hours
  • Cure time @ 75°F (thin film): 1-4 days
  • Color: 5:1 Epoxy Resin (clear), Fast Hardener (amber); cures to a light amber color
  • Note: Not intended for clear coating applications. For clear coating applications, use TotalBoat Crystal Clear Hardener.
  • For twice the working time in warmer temperatures, use TotalBoat Tropical Hardener

WARNING: The TotalBoat 5:1 Slow Hardener can expose you to chemicals including bisphenol A, which is known to the State of California to cause female reproductive toxicity. For more information, go to

Important Safety Information

Always wear protective clothing and equipment to protect your eyes, skin, and lungs when working with TotalBoat Traditional Epoxy Resin and Hardeners. Personal protective clothing should include appropriate gloves, safety glasses or goggles, a proper respirator, and a proper apron or similar protective clothing.

TotalBoat Traditional Epoxy System Technical Data

TotalBoat 5:1 Epoxy Pumps Instruction Sheet

Which Epoxy Should I Use for My Project?

Maximum Pour Depths for TotalBoat Epoxy Systems

Recommended TotalBoat Epoxies Listed by Project Type

5:1 Epoxy Slow Hardener SDS

You may also like…