You could maybe try looking for Hydroflux Pumpstation on Planets Alien,Arid, and BarrenMetal in 80-150 quantity or Thermal Interactions Ltd on Barren,Barren Moons, and Deserts in 50-120 quantity.

Or maybe if you get into Rich Ice Mining you would probably get some too.

Some traders require you to do a favor for them to unlock their trades though.

Wadtelanders sell some coolant as far as i remember

I wound up just spawning some after several hours of searching, Managed to buy a Coolant Trade Frequency as well for next time I go looking. Thanks though.

The best way I've found to get Coolantt is to visit Scrapyards and slowly buy a set of Automated Ice Harvesting Turrets from the NPC there. Once you have 4 to 6 turrets--- look for Rich and Dense Ice Asteroids.

Dense and Condensed Ice melts down in a De-constructor for Coolant, Helium, Chemicals and Toxic Waste.

good luck,

Xarq