Lye does it change water freezing point

[AndrewK]

Does lye change waters freezing point at all being that it is a derivative of sodium and salt changes it.

 

[SpurgeonH]

Sodium hydroxide does change the freezing point based on the concentration. It is not a linear graph.

Here are the freezing points at common concentrations:

5% NaOH -4°C / 25°F
10% NaOH -10°C / 14°F
30% NaOH 1°C / 34°F
50% NaOH 12°C / 53.6°F

The lye solution recommended on this site is one pound of sodium hydroxide (100%) per five gallons of water. I believe that would be around a 2.3% solution. I'm not sure what the freezing point would be for that particular concentration.

 

[W. Hilditch]

Extrapolating the above it should be about -2° C or 29° F if it’s clean.

Hilditch

 

[AndrewK]

I know mine is still on the back porch and some snow from last night froze but the lye water is no where near freezing

 

[KevinE]

Here's a graph.

http://www.havilandusa.com/downloads/Caustic_Freezing_Point.pdf

 

[Doug D.]

So, the answer to the original question would be yes, but not by much. At the concentration and temperature range with which we're actually concerned, anyway.