Horny ice question

Factual Questions
1

(Maybe ice handles would be a better description. Maybe not.)

At work we make ice with water from a 5-gallon dispenser. Sometimes half or more of the ice forms these protrusions, which look very like the gnomon on a sundial - pointed ‘horns’ sticking up at somewhere between 30 and 45 degrees. There’s no predicting when it will do it.

I’ve asked around and mostly gotten shrugs. The one explanation I got was that the ice forms from the outside in, with the center under pressure as the last bit of water expands into ice (This part I buy). And that the pure water makes ice that is more slippery so that the expanding water can escape from the center rather than just causing a bulge, like cubes made with less pure water (this part looses me).

Even if the water can escape, how does it shoot up half an inch or more and freeze fast enough that the protrusion does not fall over? It’s ice first and then it protrudes? And what about pure water makes ‘more slippery’ ice.

Hope someone out there has an explanation. Thanks ahead of time.

Hope someone out there has an explanation. Thanks ahead of time.

2

A previous discussion. You might also want to try a Google search using terms like “ice stalagmite” to see if anything more recent has turned up.

3

I wouldn’t have thought to use the keyword stalagmite. Thanks. I’ll check it and the link out.

4

ice stalagmites googled nicely with a good theory and a bunch of links here:

caltech snowcrystals site

It looks like the term “ice spike” is used in the serious literature, but it would be a messier google. According to experiments, the factors favoring spike formation are: temperature just below freezing, air currents in freezer, pure water (salt especially inhibited spikes), and plastic ice cube trays.

As for the explanation, I won’t try to summarize it.

Thanks again Hunter Hawk