Why it spins.
by
CryptoEngineer
·
· Score: 5, Interesting
As to why the rosin separates from the solder, I don't know. But I think I know why it spins.
Heat is being conducted into the rosin ball from the molten solder. The rosin is boiling or vaporising. Initially, this is symettric, but if only a small jiggle occurs, one side of the blob gets cooled by the air, and starts to vaporize at a lower rate. The other, trailing side vaporizes at a higher rate, and in reaction of the ball experiences a push from that side. The movement increases the cooling effect on the upwind side, and the process feeds on itself. Since the rosin blob touches only the liquid solder, there is little or no friction , and these tiny effects can build up.
The astronaut was lucky the rosin ball didn't come right off and hit him in the eye.
Re:Why it spins.
by
RobertB-DC
·
· Score: 4, Interesting
The astronaut was lucky the rosin ball didn't come right off and hit him in the eye.
I noticed, though, that the smoke from the heated ball of solder and rosin was clearly "rising" away from the astronaut. I'm guessing that they were using a fan or something similar to blow gases away. I'd be curious to know what happens when you melt this sort of solder without a breeze -- I'll have to google "zero gee flame" to see what the latest combustion experiments have yielded.
Also interesting... at 0:43 or so (in the Windows Media version), it looks like the guy holding the fan got distracted as the rosin bubble started spinning. The smoke starts moving in other directions, and a small chunk of... something... goes flying off to the upper right of the frame. Wonder what that was?
-- Stressed? Me?
Of course not.
Stress is what a rubber band feels before it breaks, silly.
If you don't use rosin...
by
angelrae
·
· Score: 2, Interesting
... wouldn't that prevent the problem of circling solder? It seems to me that the rosin wouldn't be necessary in space because oxidation doesn't need to be prevented. NASA says that
"hydrogen and helium are the prime components and are only present at extremely low densities" in space. Thus, the only reason I could see rosin being necessary is if the soldering would take place inside the space vessel. Otherwise, it seems to me that rosin could be removed from solder that is to be used on the space-side of these vessels.
Re:If you don't use rosin...
by
nusratt
·
· Score: 2, Interesting
"the only reason I could see rosin being necessary is if the soldering would take place inside the space vessel"
I think that was the general idea: the behavior of solder when lacking *gravity*, not when lacking *oxygen*.
I don't imagine that a lot of EVA repair work would involve soldering: anything *outside* the capsule had better use stronger connections than solder.
I wonder if soldering EVA would also run into a problem in maintaining the necessary heat.
Re:If you don't use rosin...
by
cmowire
·
· Score: 2, Interesting
I thought that maintaining heat would be a problem, too.
Then it was pointed out by another slashdotter that vacuum is an insulator. As demonstrated by the Thermos container.
Soldering *might* be useful outside of one's spacecraft eventually. I'm mostly thinking of plumbing solder for running piping, however. But I imagine that doing relatively precise soldering while wearing spacesuit gloves wouldn't be the world's easiest task. But yeah, they'll probably be more interested in space welding than anything else.
containing the smell?
by
smaksly
·
· Score: 2, Interesting
Wouldn't the smell of the solder pose a problem in the spaceship?
I remember reading a story about how strong fumes affect astronauts and that everything that goes into a spaceship gets sniffed to make sure its not emitting any unpleasant odors.
Re:Yes but what about the ants?
by
AKAImBatman
·
· Score: 3, Interesting
Believe it or not, this type of thing could be very useful to know. Sure, it's just a simple solder now, but what about other melted metals? For example, take 3D printing. Gravity tends to limit the types of shapes you can make, and the materials you can use. But what if we could 3D print steel? We could build a spaceship in record time! All we'd need are some "printer" robots and CAD software to control them!
Slashdot Mirror
As to why the rosin separates from the solder, I don't know. But I think I know why it spins.
Heat is being conducted into the rosin ball from the molten solder. The rosin is boiling or vaporising. Initially, this is symettric, but if only a small jiggle occurs, one side of the blob gets cooled by the air, and starts to vaporize at a lower rate. The other, trailing side vaporizes at a higher rate, and in reaction of the ball experiences a push from that side. The movement increases the cooling effect on the upwind side, and the process feeds on itself. Since the rosin blob touches only the liquid solder, there is little or no friction , and these tiny effects can build up.
The astronaut was lucky the rosin ball didn't come right off and hit him in the eye.
... wouldn't that prevent the problem of circling solder? It seems to me that the rosin wouldn't be necessary in space because oxidation doesn't need to be prevented. NASA says that "hydrogen and helium are the prime components and are only present at extremely low densities" in space. Thus, the only reason I could see rosin being necessary is if the soldering would take place inside the space vessel. Otherwise, it seems to me that rosin could be removed from solder that is to be used on the space-side of these vessels.
Wouldn't the smell of the solder pose a problem in the spaceship?
I remember reading a story about how strong fumes affect astronauts and that everything that goes into a spaceship gets sniffed to make sure its not emitting any unpleasant odors.
Believe it or not, this type of thing could be very useful to know. Sure, it's just a simple solder now, but what about other melted metals? For example, take 3D printing. Gravity tends to limit the types of shapes you can make, and the materials you can use. But what if we could 3D print steel? We could build a spaceship in record time! All we'd need are some "printer" robots and CAD software to control them!
:-)
So be careful about what you rag on.
Javascript + Nintendo DSi = DSiCade