Hardeners

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Catalyst for polyester, hardener for epoxy Two chemistries, two different words. Polyester and vinyl ester resin take MEKP catalyst, sold here in 2, 4 and 8 oz and dosed in cc per quart. Epoxy takes hardener: West System 205 fast and 206 slow run with 105 resin in pint, quart and gallon, and 207 special clear runs its own ratio for coating work, so check the can. Match the hardener to the resin it was formulated with. West 205 and 206 are not interchangeable with our thick epoxy hardener, which runs 1:1. Two extras live here: surfacing wax, which you add to the last polyester coat so it cures tack free, and West 405 filleting blend for thickening resin after it is mixed.