West System 209 Extra Slow Hardener

40 to 50 min pot lifeMixed 105/209: 650 cps @ 72°F

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West System

West System 209 Extra Slow Hardener

SKU:SWES-209-SA

$57.83 USD

$57.83 USD ~~USD~~

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Size: 10.6 fl oz (209-SA)

10.6 fl oz (209-SA) 42.2 fl oz (209-SB) 1.45 Gallon (209-SC)

Quantity

Key Specs

Mix Ratio: 3 parts 105 resin : 1 part hardener by volume
Pot Life: 40-50 min (100 g @ 72°F)
Viscosity: Mixed 105/209: 650 cps @ 72°F
Full Cure: Solid in 20-24 hr; maximum strength 4-9 days
Max Service Temp: HDT 117°F (cured 105/209)
Resin Type: Epoxy hardener - extra slow, for heat & long working time (for 105 Resin)

209 is the extra slow hardener for West System 105 resin: 3:1 by volume, 40 to 50 minutes of pot life in a 100 g cup at 72°F (22°C), about twice the working time of 206. It is the hardener for hot, humid shops and for big layups and glue-ups where 206 still kicks before you are done.

In a thin film you get 3 to 4 hours of working time at 72°F; it goes solid in 20 to 24 hours and reaches maximum strength in 4 to 9 days. Keep the work at 70°F (21°C) or warmer: below that the cure drags and 206 slow is the better pick. It is not a clear-coating hardener; for bright wood use 207 special clear.

105/209 bonds, laminates and builds barrier coats on fiberglass, wood, foam and metal, and it thickens with any West System filler. It meters with the 207/209 hardener pump in the 300 Mini Pump Set, and the 209-SC jug comes with the Group C extension tubes.

Specs

Ratio	3 parts 105 resin to 1 part 209 by volume (3.68:1 by weight); meters with the 207/209 pump in the 300 Mini Pump Set
Mixed viscosity	650 cps at 72°F
Pot life	40 to 50 min (100 g at 72°F)
Working time	3 to 4 hr in a thin film at 72°F
Cure	solid in 20 to 24 hr; maximum strength in 4 to 9 days; minimum temperature 70°F
Cured strength	tensile 7,300 psi (ASTM D-638); flexural 12,500 psi (ASTM D-790); HDT 117°F (105/209)
Sizes	209-SA 10.6 fl oz, 209-SB 42.2 fl oz (0.33 gallon), 209-SC 1.45 gallon

Buy 209 when heat or the size of the job is what beats you. In summer heat 206 can kick in the cup before a long layup is wet out; 209 roughly doubles that window. Match the size to your resin, 209-SA with the 105-A quart, 209-SB with the 105-B gallon, 209-SC with the 105-C jug, so the pumps meter right from both cans. See the full West System lineup.

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Technical Specifications

Made in USAMix 3 parts 105 resin : 1 part hardener by volume

Resin TypeEpoxy hardener - extra slow, for heat & long working time (for 105 Resin)

Mix Ratio3 parts 105 resin : 1 part hardener by volume

ViscosityMixed 105/209: 650 cps @ 72°F

Pot Life40-50 min (100 g @ 72°F)

Full CureSolid in 20-24 hr; maximum strength 4-9 days

Cured ColorNot for clear coating natural wood (use 207)

Max Service TempHDT 117°F (cured 105/209)

UV ResistanceTopcoat exterior work with paint or UV varnish

Tensile Strength7,300 psi (cured 105/209, ASTM D-638)

Best ForHot or humid shops & long layups; minimum 70°F

Country of OriginUSA

Compare Resins

Product	West System 209 Extra Slow HardenerYou're viewingfrom $57.83	West System 206 Slow Hardenerfrom $34.61	West System 207 Special Clear Hardenerfrom $63.15
Type	Epoxy hardener - extra slow, for heat & long working time (for 105 Resin)	Epoxy hardener - slow (for 105 Resin)	Epoxy hardener - special clear, blush-free (for 105 Resin)
Mix Ratio	3 parts 105 resin : 1 part hardener by volume	5 parts 105 resin : 1 part hardener by volume	3 parts 105 resin : 1 part hardener by volume
Viscosity	Mixed 105/209: 650 cps @ 72°F	Mixed 105/206: 725 cps @ 72°F	Mixed 105/207: 760 cps @ 72°F
Pot Life	40-50 min (100 g @ 72°F)	20-25 min (100 g @ 72°F)	20-26 min (100 g @ 72°F)
Full Cure	Solid in 20-24 hr; maximum strength 4-9 days	Solid in 10-15 hr; working strength 1-4 days	Solid in 10-15 hr; working strength 1-4 days
Cured Color	Not for clear coating natural wood (use 207)	Amber-tinted; not for clear coating	Exceptionally clear - won't cloud in humidity (blush-free)
Max Temp	HDT 117°F (cured 105/209)	HDT 123°F (cured 105/206)	HDT 117°F (cured 105/207)
UV	Topcoat exterior work with paint or UV varnish	—	Contains a UV inhibitor; topcoat with UV varnish for lasting bright finishes
Best For	Hot or humid shops & long layups; minimum 70°F	Extended working time & warm shops; minimum 60°F	Clear-coating natural wood & carbon fiber; minimum 60°F
	Selected	View	View

When should I use West System 209 instead of 206?

Use 209 when heat or the size of the job is the problem. It gives about twice the working time of 206: 40 to 50 minutes of pot life in a 100 g cup at 72°F and 3 to 4 hours in a thin film. That suits hot, humid shops and big layups or glue-ups. Below 70°F it cures too slowly, so stay with 206, or 205 in the cold.

What is the mix ratio for West System 105 and 209?

3 parts 105 resin to 1 part 209 hardener by volume, or 3.68 to 1 by weight. The 300 Mini Pump Set meters it at one full stroke of resin to one full stroke of hardener with its 207/209 hardener pump. Match group sizes: 209-SA with 105-A, 209-SB with 105-B, 209-SC with 105-C.

Can I use 209 Extra Slow Hardener for clear coating wood?

No. West System says 105/209 is not intended for clear coating natural finished wood. For bright work and clear finishes use 207 Special Clear Hardener. 209 is for bonding, laminating and barrier coating where the epoxy will be painted or covered.

How long does West System 105/209 take to cure?

At 72°F a thin film goes solid in 20 to 24 hours and reaches maximum strength in 4 to 9 days. Heat and thicker applications speed it up. Keep the work at 70°F or warmer; below that the cure slows down a lot.