Ahh thanks to Nuplex’s customer support we’ve now been collectively enlightened about their product range.
Polyplex 3008 with its gel time of up to 100 minutes and reduced shrinkage would be superb for water effects particularly since it can be poured up to 3 litres at a time! Alas Nuplex only sell Polyplex 3008 in a 20 litre tin for $220 NZ. Ack! Twenty litres of resin would allow me to produce several tabletop oceans…
Polyplex 3089 is less desirable because it has a much shorter gel time of up to 50 minutes (with only 0.5% of hardener) and can’t be poured in more than a 5mm layer but it is sold in 1 litre tins for $27NZ. Layering is a hassle and suggests that the resin shrinks as it cures. However I guess the upside is you can apply different coloured layers with embedded items for some more interesting effects…