Eutectic tank solution

[RaymondR]

I was looking for my copy of "Refrigeration For Pleasure Vessels" to refresh my memory of why one should not use antifreeze as a eutectic fluid but have not been able to find it.

However I think the reasoning went something like;

Antifreeze solutions are not true eutectic fluids and progress to freezing over a broad range of temperatures as the glycol portion tends to separate out thereby changing the solution concentration and freezing point.

I'm working with a 75 year old memory here but I think that's pretty well what it said.