Cure system
Hardeners & Accelerators for Polyester Cure
Room-temperature polyester cure is a redox pair, not a single additive. A cobalt salt decomposes the peroxide catalyst at ambient temperature to generate radicals, and styrene then crosslinks the polyester into a rigid network. Samrat Poly Resins supplies both halves: MEKP as the catalyst and cobalt octoate as the accelerator.
These two are not alternatives to each other. A resin that is already pre-accelerated needs only the peroxide; one that is not needs both, added separately and in the right order.
Products
Choosing between them
Catalyst and accelerator do different jobs
Catalyst / initiator
MEKP Hardener
Methyl ethyl ketone peroxide. It is the radical source, used at a low percentage and not consumed stoichiometrically, so adding more does not give a harder cure — it gives a faster, hotter one, with the defects that follow.
View MEKP HardenerAccelerator / promoter
Cobalt Octoate
The cobalt salt that lets MEKP decompose at room temperature at all. Without it a cobalt-dependent system will not cure at ambient. Many resins arrive pre-accelerated, in which case this is already in the drum.
View Cobalt OctoateThe one rule that matters more than any other on this page: never bring MEKP and cobalt accelerator into direct contact. Mixed together undiluted they can react violently. The accelerator goes into the resin first and is stirred in, then the peroxide goes in separately. Peroxides also lose activity in storage and have real temperature limits, so check the age of stock before blaming a resin for a slow cure. Dosage belongs to the resin grade and the shop temperature, so confirm it against the grade's own data sheet rather than carrying a figure across.
Guides
Read before you specify
Enquiry
Request a quote for hardeners
Tell us the finished product, the service condition and the quantity, and the right grade can be matched to it. Samrat Poly Resins manufactures at Doraha, Punjab.