Hardener K-25

Catalyst to no-bake resins



Package Size Product Code
Kovete K-25 kontti 2" u T8060.985

Mixture of para-toluene acid and phosphoric acid

Density/specific weight

1290...1320 kg/m³

Package sizes

1000 l container


Can be stored unopened in a well ventilated, cool place for 12 months.

Instructions for use

A typical mixing ratio is 1 – 1.5 % of resin to the amount of sand. The suitable amount of catalyst is 30 – 50 % of the resin amount used.
The final mould strength depends on the binder, dosage, sand quality and curing conditions. A higher binder dosage is recommended for core moulding.
Different types of catalysts and dosage are used for adjusting curing speed. A higher catalyst amount speeds up the curing process, even though to some extent will reduce the final strength. Catalyst overdose (over 60%) will result to longer stripping time.
The sand must be free from alkaline impurities, preferably washed, cooled and dry. The sand temperature must not exceed 35 °C, otherwise the sand will cure in the mixer or in too early stage. The higher the sand temperature, the less catalyst is needed and correspondingly, the lower the sand temperature, the higher dose of catalyst is needed. No-bake resin can be used as such without any extra measures with neutral and acidic sand (quartz, chromite, zircon etc.)

Additional information

The information given in this product data sheet is based on our tests and our practical knowledge. The technical data is defined in standard conditions. Variations in local working conditions and methods will affect the product performance and result. The result is also strongly affected by working methods. We guarantee the high quality of our products according to our Quality Management System. No liability can be accepted from incorrect use of the product or prevailing conditions, over which we have no control. Thus, we cannot be held responsible for the final result. The user of the product must test the product’s suitability for the intended application.

Environment and safety

NOTE! When mixed together, resin-catalyst compound generates an intensive, heat-producing explosion-like reaction. DO NOT MIX WITHOUT SAND! Should this happen, add immediately plenty of water in the mixture. Ensure efficient ventilation in the working premises
Avoid unnecessary skin contact and exposure with the fresh product, use safety gloves, safety glasses and protective clothing.
Refer to a product specific material safety data sheet.
For more information on product and package disposal, visit www.kiilto.com.

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