That's no moon

January 29, 2013 3:25 PM

Help me create the perfect Death Star ice sphere.

My lovely fiancee bought me this kick ass Death Star ice mold for Christmas and I love it. Problem is that the iceological terrors I've constructed are insignificant next to the power of the ones posted on ThinkGeek; mine are cloudy and they have a slight vertical line running through them.

I also have no idea how much water to use. I either use too much and some will spill out the top or too little and I'll only get the super laser portion (which is the most important part but still...). The instructions have long since been discarded.

For those of you with extensive Death Star construction experience: how much water do you use and what are your tricks to get the clearest Death Star this side of Alderaan?

Help me, Metafilter, you're my only hope.

posted by Diskeater to Grab Bag (16 answers total)

Best answer: Use boiling hot water.

Really!
posted by seanmpuckett at 3:26 PM on January 29, 2013 [2 favorites]

Yup, you gotta boil the water. As for the lines, once you've removed the sphere from its mold, take a clean washcloth, dip it in warm water, and gently smooth out the seams. The warm water should gradually sand them off.
posted by These Birds of a Feather at 3:32 PM on January 29, 2013

Response by poster: Sorry, I wasn't clear in the original question. "Vertical lines" isn't accurate. It's more like a vertical sphere shape on the inside of the death star. It's not a physical seam (actually, one of the great things about this mold is the complete lack of any seam). I've taken a picture here to try and show what I'm talking about but it's a bit tricky to capture.

Boiling the water first is a great tip and I'll give that a shot tonight.
posted by Diskeater at 4:17 PM on January 29, 2013

In the amazon reviews of the same product I see a few comments saying they just had to experiment to get the quantity of water right. So I don't think the manual would offer you much guidance there. But ice is about 8.3% bigger than water. I don't remember enough math to tell you how far you have to fill a sphere to have 92% of the volume*, so just fill it all the way, measure the water with a liquid measure, and do a bit of math.

*(that's 1 / 1.083, not 1 - 0.08, though the result's the same)
posted by aubilenon at 4:23 PM on January 29, 2013

You could put some paper towels on top of it, dipping just above the top of the ideal Death Star, so if the water level rises too high while freezing, the excess gets absorbed and carried away by wicking action.

Ok ok, in reality, that'll work for a while then just freeze the paper to the death star, but it might still be easier to snap off the tip of the frozen paper inverted-pyramid, than to try to remove a large chunk of ice overfill.
posted by anonymisc at 4:39 PM on January 29, 2013 [1 favorite]

If it rises out the top then a hot towel would help melt the excess away as was suggested.

I'm no expert, but I read this when doing a search for ice sculpting...

'If you choose to use distilled water, which will make your ice sculpture clearer than regular tap water, fill the mold with the distilled water and let it sit out for a few hours, or even overnight, before putting it in the freezer.'

I want a picture when you make the next one!
posted by Youremyworld at 4:43 PM on January 29, 2013

If I'm seeing it right, that line looks like a fracture plane within the ice. You can probably reduce or eliminate it by using boiled and/or distilled water, as other people have suggested (boiling reduces dissolved gas; distilling reduces dissolved minerals, which are nucleation points). If that doesn't work, it might be because the ice freezes from the outside in and the water inside cracks the ice shell as it freezes. Perhaps agitating or flexing the mould as the water freezes would help the ice form more evenly, or perhaps inserting a heated skewer when the mould is partially frozen would give the water inside a channel of escape.
posted by Joe in Australia at 5:44 PM on January 29, 2013

inserting a heated skewer when the mould is partially frozen

Don't do this - or at least if you do, don't leave the skewer in too long or the Death Star will freeze around it, and then removal of the skewer will leave an exhaust port in the Death Star that is vulnerable to proton torpedos.
On second thoughts, do this.
posted by anonymisc at 6:24 PM on January 29, 2013 [7 favorites]

Response by poster: Using the power of science and a measuring cup, I deduced that the mold can hold about a 1/2 cup of liquid. I boiled some tap water and put a little over 1/4 cups of water into it. I'll let it set overnight and report my findings tomorrow.
posted by Diskeater at 8:32 PM on January 29, 2013

Best answer: These are the steps I have followed.

Use filtered water
Boil
Cool and boil again
Freeze

Works great.
posted by Leenie at 9:24 AM on January 30, 2013

Response by poster: First report: Only got 1/2 a Death Star with 1/4 cups of water. Maybe a little clearer but not by much. Didn't see any weird vertical sphere but it's possible there wasn't enough water to form one.

Will try a little less than 1/2 a cup of tap water, boiled twice. I'll pick up some bottled/distilled water shortly and give that a try too.
posted by Diskeater at 3:06 PM on January 30, 2013

If the whole thing is 0.5 cups (~118 ml), why not use aubilenon's formula and measure out (scales are probably best) 109 ml of water rather than trial and error with 59 ml then "a little less"?
posted by turkeyphant at 6:04 PM on January 30, 2013

Response by poster: Second report: Using water that was boiled, cooled, and boiled again seemed to do the trick! Here's a picture. It's not perfect but it's way better than before.

I only got about 70% of the mold so I still have to dial in the amount of water. Next up is using twice boiled bottled/distilled water. I'll probably get to that over the weekend.

Turkeyphant - I don't own a scale and I don't plan on getting one for this. I did find a turkey baster and I plan on using that.
posted by Diskeater at 3:50 PM on January 31, 2013

Best answer: If you don't have a graduated pyrex liquid measure, can you just fill it all the way and then take out about 2 tsp?
posted by aubilenon at 4:14 PM on January 31, 2013

Response by poster: Third report: Bottled water, boiled, cooled, boiled again: pretty much same result as tap.

I'm also leaving the mold out for a few minutes instead of running hot water over it in order to get the Death Star out and I haven't seen those vertical spheres since.
posted by Diskeater at 2:16 PM on February 3, 2013

The "vertical sphere" will have formed long before you take it out of the freezer. Speaking of which, how cold is your freezer? It might help to cool the water as quickly as possible.

If you don't have scales (not sure how people survive without) why not just use any measuring jug? In any case, I was more wondering why you tried that amount rather than trying to get closer to the correct amount...
posted by turkeyphant at 11:59 AM on February 6, 2013