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#209 Extra Slow Hardener, 1.45 gallons (209-SC)
Model # 372888
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Choose the right hardener to control the cure time of 105 Epoxy Resin at the temperature at which you will work.
209 Extra Slow Hardener® is formulated for use with WEST SYSTEM® 105 Epoxy Resin® or general coating and bonding applications in extremely warm and/or humid conditions or when extended working time is desired at room temperature. Provides approximately twice the working time of 206 Slow Hardener®. 105/209 forms a high-strength, moisture-resistant solid with excellent bonding and coating properties. The mix ratio is 3 parts resin to 1 part hardener by volume. Not intended for clear coating.
PROJECT USES
- Marine
- Boat Repair
- Bonding
- Fabrication
- Barrier Coating
CURE TIME
- Pot life (100 grams cupful):
- At 72°F (22°C): 40 to 50 minutes
- Working time (thin film):
- At 72°F (22°C): 3 to 4 hours
- Solid state:
- At 72°F (22°C): 20 to 24 hours
SIZES
- 10.6 fl. oz (209-SA)
- 42.2 fl. oz (209-SB)
- 1.45 gallon (209-SC)
Details:
- Best Use: Extra-Slow Hardener for 105 Epoxy Resin
- Capacity: 1.45 Gallons
- Cure Time: 20 to 24 Hours (Working Time 3-4 Hours) at 72 F
- Type: Hardener
INCLUDES
- (1) 1.45 Gallons Extra Slow Hardener
All other WEST SYSTEM products are sold separately.
For the suitability of fillers for specific applications, see the Filler Selection Chart.
For more about 105 Epoxy Resin and the complete line of WEST SYSTEM products, see the Product Selection Guide.
Additional Info:
Choosing the Right Epoxy System
WEST SYSTEM® 105 Epoxy is a professional quality, two-part epoxy system developed for high strength and good versatility. The Epoxy Selection Guide is a handy tool to help you pair 105 Resin with a choice of four hardeners to best match your working temperatures, desired cure speed, and coating clarity.
Estimating Coverage for Fabric Application
Estimating how much epoxy is required to wet out fabric is based on the fabric weight and square footage. We provide estimates of the amount of epoxy needed to apply 1 sq. ft. of fiberglass cloth. Estimate Coverage in images below.
Warm Weather Bonding
WEST SYSTEM Epoxy’s cure times are based on an ambient temperature of 72°F. In warmer temperatures, epoxy cures faster. Here is what you need to know to ensure adequate working time when using epoxy in warm conditions. Epoxy cures by a chemical reaction between the resin and hardener that releases heat, called an exothermic reaction. The larger the volume of epoxy the more heat that is generated.
Many epoxy users have seen pots of epoxy smoke and bubble due to uncontrolled exotherm. The good news is you can do to prevent this. A good rule of thumb for gauging cure speed is that for every 18°F increase above 72°F, the working time and pot life will be cut in half. To maximize the working time of the epoxy, consider how much time you need and what temperature you’ll be working at, then select the hardener accordingly. For hot temperatures, we recommend 209 Hardener.
Epoxy Pot Life vs. Working Time
The pot life listed on the WEST SYSTEM technical data sheets refers to a confined mass of 100 grams of epoxy at 72°F. Pot life is always shorter than working time because epoxy contained in a pot kicks off faster than epoxy spreads into a roller pan (thin film). Spreading out the epoxy dissipates heat, extending its working time 209 Extra Slow Hardener TDS.
An Epoxy Cooling Box
To slow epoxy’s reaction in very warm temperatures, create a foam cooling box that is glued together and sealed to hold your roller pan. Fill the inside of the foam box with tap water that will act as a heat sink and increase epoxy’s working time. An ice cube or two can be added to the water bath as long as you do not chill the epoxy too much. Chilling the epoxy too much can cause moisture in the air to condense on the epoxy. Moisture can cause the epoxy to cure at a faster rate, become cloudy and reduce its cured physical properties.
Metering Pumps: For group sizes "A", "B" and "C", 205 and 206 Hardeners are mixed with 105 Epoxy Resin in a ratio of 5:1. 207 and 209 Hardeners are mixed with 105 Epoxy Resin in a ratio of 3:1. To make sure you get the proportions right, we highly recommend purchase of the 300 Mini-Pump Kit, which meters the hardener and resin in the exact proportions you need. For group size "E" and larger sizes, we suggest use of either the 306-23 Special Purpose Resin/Hardener pump (Model 128845), which dispenses hardener and 105 Epoxy Resin at a ratio of 3:1, or the 306-25 Special Purpose Resin/Hardener pump (Model 335703), which dispenses hardener and 105 Epoxy Resin at a ratio of 5:1.
Instruction Manuals
Gougeon Brothers, Inc. offers a range of detailed epoxy instruction manuals to help you get started with WEST SYSTEM Epoxy products. All of our print publications are available as free downloads. Download Instruction Manuals
Epoxy Shelf Life & Proper Storage
WEST SYSTEM resins and hardeners do not have a strict shelf life. Certain changes may make them less effective for some jobs, but the resin and hardener will still be reactive. Because we are an ISO 9001 company, lot numbers are provided on containers and we keep retains of every batch of hardener we make up to 2 years from the date of manufacturing, and resins for 3 years. However, the actual shelf life is typically far longer.
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WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.
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