Hardeners & Catalysts

These are consumables rather than one-off purchases, and they are bought as a working pair. In a polyester system the catalyst starts the reaction, while the accelerator allows it to proceed at workshop temperature — separate products doing separate jobs. Which you need, and whether you need both, depends on whether the resin you are using is already pre-accelerated.

Accelerator and peroxide catalyst are dispersed into the resin separately and are never combined directly with each other. Gel time in practice moves with ambient temperature, resin temperature and mix volume, so figures from another site or season rarely transfer. For background on how the accelerator functions in a cure system, see theCobalt Octoate guide.

Documentation differs between the two products, and the difference is worth knowing. MEKP Hardener carries a supplier TDS and SDS, which identify it as an organic peroxide initiator listed for unsaturated polyester, vinyl ester and gelcoat systems. Cobalt Octoate has no supplier document on file with us, which is why its product page publishes no technical values — the accelerator is supplied, but we are not in a position to state figures for it. If your process needs documented accelerator data, raise that in the enquiry so it can be requested from the supplier rather than assumed.