Hardener W 300 (300 min)

Hardener for Epoxy Resin L and Epoxy Casting Resin "water-clear"

• Very low viscosity (± 300 mPa•s, bei 25 °C)
• Fast impregnation of glass, aramid and carbon fibres
• Also suitable for casting (up to 2 cm layer thickness in one operation)
• High transparency
• Largely lightfast and colourfast
• Adhesive-free hardening (hardening from +15 °C)
• Heat deflection temperature approx. 65 °C
• Very good impact strength

Epoxy resin L with hardener W 300 is a frequently used laminating, coating and casting resin system from the R&G product range. Due to its low surface tension, good adhesion and low curing shrinkage, it is also very suitable for bonding wood, metal and PS rigid foams such as Styropor®. It can be processed in all common processes such as hand lamination, pressure and vacuum impregnation as well as pressing and winding.

Mixing ratio:
100 : 35 parts by weight of resin to hardener

Pot life (135 g / 20 °C (68 °F)): approx. 300 minutes
Curing time: approx. 24–72 h (depending on volume, layer thickness and temperature). If the system is processed in thin layers / laminates, the curing temperature should not be less than 22 °C (72 °F).

Processing:
For optimum results, resin and hardener should be dosed by weight. (Mixing ratio by weight is not equal to mixing ratio by volume due to different specific weights of resin and hardener.)

After mixing the resin and hardener, the casting resin must be poured into the mould as quickly as possible to avoid an exothermic reaction in the mixing vessel. This is especially true when larger quantities are processed.

The reaction heat (exothermic) generated during hardening limits the maximum quantity to be poured in one operation and the layer thickness.
The higher the temperature and/or layer thickness and/or volume, the shorter the processing/gelling time.
If a certain limit is exceeded, the resin system heats up exponentially until undesired reactions finally occur: The casting discolours completely or in places, from light yellow to dark brown, cracks appear and increased shrinkage occurs. Furthermore, a restless, wavy surface is formed. In extreme cases, the casting can "boil" completely or partially. Temperatures above 100 °C then occur.

Layer thicknesses up to 5 cm for small volumes up to approx. 500 ml and layers from 1-2 cm for large volumes up to approx. 30 liters can be cast.

Large moulded parts ("rivertables" etc.) with layer thicknesses of more than 20 mm should be cast in two or more work steps/layers one after the other at intervals of about 12 hours.

At temperatures above 25 °C (77 °F), we strongly advise against casting larger layer thicknesses and/or larger volumes in one operation.

Please order Epoxy Resin L or Epoxy Casting Resin "water-clear" separately.