MEKP Catalyst Hardener — Fibreglass Resin Activator

MEKP catalyst hardener is the liquid activator that triggers the curing process in polyester resins, topcoats, and gel coats used in fibreglass pool lining. Without catalyst, the resin stays liquid and never sets. Add the correct percentage of catalyst to your resin mix and a chemical reaction begins that hardens the resin within 15 to 30 minutes depending on temperature. This is Arkema Luperox K1SN E, an industry standard methyl ethyl ketone peroxide catalyst used by fibreglass applicators across South Africa.

Dosing — How Much Catalyst to Use

Use between 1% and 3% catalyst by volume of resin. In hot weather, use less catalyst because heat accelerates the curing reaction. In cold weather, use more to ensure the resin cures properly. As a starting point, 10ml per litre of resin in summer and up to 30ml per litre in winter. Too little catalyst and the resin stays soft or tacky. Too much and the resin cures too fast, generates excessive heat, and can crack or discolour. Always measure accurately — do not guess.

Safety

MEKP is an organic peroxide and must be handled with care. It is flammable, harmful if swallowed, and causes severe skin burns and eye damage. Always wear gloves, eye protection, and work in a well-ventilated area. Store in the original container in a cool place away from heat, sparks, and direct sunlight. Never mix catalyst directly with accelerator or cobalt — this can cause a violent reaction. Always add catalyst to resin, never the other way around. Keep out of reach of children. UN 3105 classified.

Specifications

Product: methyl ethyl ketone peroxide (MEKP). Brand: Arkema Luperox K1SN E. Type: organic peroxide catalyst hardener. Available in 1kg and 5kg. For use with polyester resins, topcoats, and gel coats. Store cool and away from heat sources.