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darryl
09-09-2006, 02:21 PM
Something's been missing in my life lately, and this morning I realized what it was- I haven't experimented with anything for awhile, just to see if, or what, or why, -

Anyway, I came across an aluminum baseball bat and I got interested in how it's constructed, the thickness of metal, etc. I cut the handle off at the end of the tapered section, and was happy to see about a .125 or so wall thickness. Then I thought, gee, how much water would it take to fill this?- my aim really was to measure the wall thickness throughout as best I could, and I was going to do this by a water displacement method. Enaway, I ended up filling it, and with hot water as that happened to be the tap that I turned on. Ok, so it took 550 ml to fill it, semi useless information, who cares. Then I thought, gee, what if I cooled this whole thing now, the metal's going to contract and some water will spill out the top. Whooppee ding. So I'm cooling it- the surprise part was that the water level actually dropped inside the narrow neck of the bat. Now I'm thinking.

So what has happened? Did the metal expand as it cooled, allowing for a slightly increased internal volume- did the metal shrink ( as I assumed would happen) but the volume of water shrink even more? How much expansion/contraction does water go through with temperature changes? Obviously it expands as it cools past the freezing point, and it expands greatly as it heats past the boiling point, but what of the range between?

Ok, that's my thing for today.

A.K. Boomer
09-09-2006, 02:40 PM
Cant give you specs although i know who will, all i can say is my comparison with car cooling systems and the size of the purge tank, low when cold and high when hot, all the aluminum Rad. cores and the aluminum engine block (subies and honda's), yet when these parts cool in compairison to the water/ethlene glycol its the liquid that goes though more expansion and contraction, about a pint to a quarts worth...

Fasttrack
09-09-2006, 02:40 PM
I dont know any of the coeficients for it, but the water probably "contracted" more than the aluminum did. Water, in a pure state and free of oxygen will continue to shrink in volume well below 0 degrees celcius. This state of super-cooling is rare in water because it must be pure to prevent the growth of ice crystals. [<edit> and it must be under pressure! ] This is the technique behind making ice for ice sculptures - it undergoes various agitations to remove and dissolved oxygen and it is pressurized and super cooled before it is allowed to freeze to form a clear, almost glass like ice block. Anyway, even tap water will continue to decrease in volume until abot 4 degrees celcius.

A.K. Boomer
09-09-2006, 02:50 PM
I knew that but did not realize they do that for ice scuptures very "cool"

does this make the Ice colder? there is a simular discussion in the making of ice cream the old fashioned way, adding salt to ice releases colder temps or removes heat so the center cream that it surounds freezes...

Fasttrack
09-09-2006, 03:09 PM
Well technically you can cool solid ice as cold as you want it, all the way until it reaches a point of super-fluidity but you need a really really good "freezer" to be able to remove enough energy to reach that point. If you add some kind of solute to the water, like salt, and then freeze it, it will freeze at a lower temperature but it will then melt sooner. When you add salt to the old-fashioned ice cream makers you'd be adding it to the ice that is around the outside of the ice cream. Because of osmotic pressure, the water wants to mix with the salt and dissolve it but this can only happen when the water is in liquid form. To melt it requires heat so when you add salt to an ice-cube your really just speeding up the process of melting to pull more heat out of the surrounding area. In fact, you can get bad cold burns from an icecube and salt if you put some salt on an icecube and press it against your palm for a few seconds. Basically adding salt just makes the ice pull the heat out of the ice-cream much faster. Since it can pull from the ice-cream faster than it pull heat through the insulation from the outside air, the temperature of the ice-cream actually drops below the freezing point of water while the ice on the outside is melting. Just a chemical refrigerator.

John Stevenson
09-09-2006, 03:13 PM
Does the water come out when you swing at the ball ?

.

Evan
09-09-2006, 03:25 PM
I dont know any of the coeficients for it, but the water probably "contracted" more than the aluminum did. Water, in a pure state and free of oxygen will continue to shrink in volume well below 0 degrees celcius.
Waitaminute Fasttrack. You need to review your physics. Water continues to contract until just before freezing and then begins to expand before it freezes. Supercooling it makes no difference as this happens at (a moment while I look it up)... Ah yes, 4 degrees celsius. At this temperature water has minimum volume and expands as the temp goes in either direction.

Water is a very strange compound and can exist in numerous forms, gas, liquid, and many forms of ice and strange in between states.

This is an excellent web page that explains in detail the 63 anomalous properties of water.

http://www.lsbu.ac.uk/water/anmlies.html

topct
09-09-2006, 03:31 PM
Just curious. How would filling it with water, either cold or hot help you measure the wall thickness of the bat?

"my aim really was to measure the wall thickness throughout as best I could, and I was going to do this by a water displacement method."

I have always though they might make a neat exhaust pipe.

Guido
09-09-2006, 03:39 PM
As I wuz taught, the harder you apply the surface of a slider to a slidee, the harder it becomes in overcoming friction twix the two. Not so with ice. Frozen water (ice) exhibits the opposite physic, otherwise ice skates won't work.
G

LarryinLV
09-09-2006, 04:04 PM
OK...????

Sooooo....When you're up to bat, and someone throws you a slider.....The right tool is a .125 wall aluminum bat filled with supercooled liquid???

What alloy would that Al bat be to take best advantage of this phenomenon??



Never mind, I'll go back to the shop now.

topct
09-09-2006, 04:07 PM
Darnit, now I have to go and buy one the things. i see them for a couple of bucks apiece at the local Goodwill store.

I would cut the ends off and see if I could tune it to some musical note.

With a bunch of them tuned in a diatonic scale.......hmmmm.

Fasttrack
09-09-2006, 04:48 PM
Hence my line: "Anyway, even tap water will continue to decrease in volume *until* about 4 degrees celcius."

Evan - perhaps i was splitting hairs but...

My mistake earlier - i was thinking only of super-cooling under pressure. I did not make that clear; indeed i had not distinguished between the differences of super-cooling and super-cooling under pressure in my mind. Perhaps you missed this from that site:

"The result is a shift in the temperature of maximum density to lower temperatures. At high enough pressures the density maximum is shifted to below 0°C (at just over 18.84 MPa). "

As density is a measure of moles of water per volume - an increase in density when the amount of H20 molecules (i.e. moles of water) remains constant, the volume will decrease.

darryl
09-09-2006, 04:54 PM
Dang! Now I have to go back and get a few more of these elcheapo kids bats. I suddenly have a need to make an organ. :)

Far as measuring the wall thickness using water, I would have totally immersed the bat part in water in a slender container, then filled the container to some level that I marked on it. Then I would carefully remove the bat and pour all the water back into the container. Mark the level again. Then fill the container back to the first mark, then pour the water into a measuring container until the lower mark is reached. The amount of water in the container would correspond to the volume of material in the bat part. Then measure the surface area of the part, apply a correction factor based on the expected wall thickness, then some more math to get the actual average thickness.

I realise that this method is fraught with errors, but that's the way I envisioned doing it.

Fasttrack
09-09-2006, 05:01 PM
Darryl - you don't happen to be an engineer do you? :D Thats the kind of expierement i'd expect from science teachers or engineers or others who may be very brilliant. Its great in theory but not so easy in practice... :) I've had a couple of those ideas...

DICKEYBIRD
09-09-2006, 05:17 PM
Step away from the bat! Do you know how many poor, defenseless children have been hurt by baseball bats? Not to mention supercooled bats modified by unlicensed bat butcherers!

MUCH safer to teach them how to play Jarts in a responsible manner.[:)][:D]

Fasttrack
09-09-2006, 05:22 PM
"Step away from the bat! Do you know how many poor, defenseless children have been hurt by baseball bats? Not to mention supercooled bats modified by unlicensed bat butcherers!

MUCH safer to teach them how to play Jarts in a responsible manner.[][]"

lmao

Evan
09-09-2006, 06:10 PM
Fasttrack,

I missed your mention of pressurizing and I am well aware of the changes that pressure makes to the properties of water. I had not heard that they freeze the water under pressure to make carving ice as it isn't normally necessary. Water can be supercooled without being placed under pressure as long as it is pure and gas free. An easy way to remove dissolved gases is to simply boil it.

Darryl

It seems to me that you can arrive at the average thickness by weighing the bat. Then use water to figure how much of the bat is hollow by weight. This gives you a relative percentage difference between a solid bat and a hollow one. Then measure the OD and apply the percentage.

wierdscience
09-09-2006, 08:15 PM
The use of "aluminum" and "Baseball bat" in the same sentence is blasphemy:D

BobWarfield
09-09-2006, 08:37 PM
Water is a very strange compound and can exist in numerous forms, gas, liquid, and many forms of ice and strange in between states.

This is an excellent web page that explains in detail the 63 anomalous properties of water.

http://www.lsbu.ac.uk/water/anmlies.html

It's not water's fault, it's got "Dipolar Disorder".

Cheers,

BW

Evan
09-09-2006, 09:18 PM
:D

http://vts.bc.ca/pics/pixel.gif

darryl
09-10-2006, 01:33 AM
Interesting read. If I had 63 anomalous properties, I'd have bipolar disorder too. :)

tryp
09-10-2006, 02:55 AM
4 degrees, but Evan beat me to it.

IOWOLF
09-10-2006, 08:15 AM
Umm, perhaps you have too much time on your hands.

Evan
09-10-2006, 08:23 AM
It's actually 3.984°C. :)

[edit]

That's really an important property of water. It means that a body of water can't freeze on the surface until the entire body has cooled to near that temperature. When the water near the surface cools and becomes denser but not frozen it sinks to the bottom pushing the warmer water up. I'm sure that Tryp has seen the effect. When we get a real cold snap before the lakes have frozen they "turn over". For a few days or a week the entire lake will look like it is almost boiling as warm water comes to the surface and releases large clouds of dense mist from random areas of the surface. Then, fairly suddenly it stops and the surface skims over with ice.

RobDee
09-10-2006, 08:53 AM
To determine volume both the water and bat must be at relatively the same temperature. That also includes the vat of water you use to measure the bat displacement.

Either way the wall thickness of the bat may very well vary along its length.

Rob Dee

Millman
09-10-2006, 09:08 AM
Yesterday while dumping my ice cube trays, I noticed they had sand and oil in them. Got me thinking that had something to do with that episode of 'Superman' in the 50's where alien underground creatures were crawling up through oil well casings. Have to go outside and start looking around. Did they have alum. bats in that episode?

dicks42000
09-10-2006, 02:37 PM
Robdee partly beat me to it. After all the Archimedes-like measuring of water volumes, you'll end up knowing the volume of aluminum that makes up the bat.
The shape is likely rotary-swaged (almost like a slow, graunching spinning process) or forged over a mandrel so the wall thickess may vary at changes in dimension.
Why not use a d-meter or similar ultra-sonic means to measure the wall thickness at various "stations" and map them. Or just fire up the bandsaw & cut sections out of the thing....Then make napkin rings to please SWMBO.
Recycling and experimentation at it's best.
Rick

Hexhead
09-10-2006, 11:12 PM
Ahhhhhhhhhhhhh!!!!!

Evan
09-11-2006, 12:51 AM
Drill a small hole in side of the bat and look.

TECHSHOP
09-11-2006, 02:53 AM
Didn't you and I have a disscusion on this water thing a while back, I don't remember why or what the finial result was (who keeps score?). The inclusion of a baseball bat is an interesting addition. I prefer the wooden ones, as I can burn them during the off season for heat. I think I would just cut the bat the "long" way and get out my mic and collect several thousand "data points" and then plot them in a CAD program.

darryl
09-11-2006, 03:06 AM
Water certainly is an amazing substance. I was just thinking about what would happen to supercooled water as it began the transition to ice. Has it already expanded to the size it would be when frozen, or does the act of freezing correspond to the ten percent or so increase in size? If it's supercooled and then could suddenly transform into ice, that could be an almost explosive event.

Anyway, back to the bat. It appears to have been cast, maybe spun cast, though I am not yet seeing how the end gets formed so it becomes one piece. The knobby end of the handle is welded on, and there's a tiny hole there to relieve whatever pressure variations would be occuring during manufacture.

The whole idea of measuring the wall thickness was to determine whether it was fairly uniform or whether the fatter part got thinner. This would probably make a difference to whether it could be used for some other particular application. An example of using this knowledge would be ordinary aluminum pipe. Much of the time, it won't have an equal thickness wall, one side might be thicker than the other. As such, my test would have been fatally flawed, since it wouldn't show this up.

topct
09-11-2006, 07:53 AM
http://www.aluminumbats.com/index.asp?PageAction=Custom&ID=4

Paul Alciatore
09-11-2006, 10:08 PM
OK, the linear thermal expansion of aluminum is in the range of 21 to 25 parts per million, per degree C. The volumetric coefficient is generally taken to be three times the linear coefficient so for aluminum that would be 63 to 75. This will vary with different alloys and also with temperature.

The volumetric coefficient for water varies even more with temperature and at the 4 degree point it is actually zero, but in the 20 to 30 degree C range, it varies between 210 and 290, again in parts per million per degree C. It is even higher at higher temperatures.

So common "hot" water has a far higher coefficient than aluminum. Since the aluminum of the bat is in intimate contact with the water the two are likely at or very close to the same temperature. As the water and bat cool down, it would be expected that the water would lose more volume than the bat.

So there's the numbers.

darryl
09-11-2006, 10:26 PM
That's interesting, Paul. I wouldn't have thought water would change that much at 'normal' temperatures. Hmm. Learn something everyday.

hughman
09-11-2006, 10:38 PM
You could try measuring the density and quantity of aluminum in the bat electrically. You'd need to determine the alloy, and it's electrical resistance to a current, but that can be looked up. since it's a fairly large piece of metal, you'll need a fairly large current: 120v won't cut it, and wouldn't be much fun anyway. Tap into the local 30KV transmission line for the power (Oh, yeah, you'll need to get an accurate measurement of the current, and the ohms, so borrow a line truck for the experiment)

a simple extrapolation will yield perfect results!

You won't need the bat afterwards, will you?