[teyyet2004]

Hi. Can you mix isopropyl alcohol with methanol as an additive so water doesn't freeze? With both together do they have a lower freezing rate?

[P]

I think the traditional solvent to use is some form of glycol or ethylene glycol - which is the classic 'antifreeze'. It is toxic though, so maybe IPA would be better - yes, I think IPA would work. Not sure how much better it is mixed with methanol... but methanol is toxic also, so maybe just use the IPA if it is strong enough on it's own.

I do not know from the top of my head if mixing in meths lowers the freezing point further from using just IPA or Meths alone...  I wouldn't have thought it would depress it much further if there was an effect. The alcohol should work fine.

[Babcock_Hall]

What is your application? 

[P]

What is your application?

Quite - if we knew what you were doing it would be easier to prescribe a solution.

Just out of interest though, regarding the mixture  -  Would there be some kind of eutectic depression in the freezing point below that of either solvent once mixed?

[OrganicDan96]

how about propylene glycol?

[Enthalpy]

+1 for propylene glycol, which is the standard nontoxic antifreeze.
It won't evaporate away nor catch fire even when pure, and doesn't stink.