it forms large flakes of a white crystal like powder that eats the aluminum battery racks.
What is it?
A very common problem is battery acid dripping onto aluminum,
it forms large flakes of a white crystal like powder that eats the aluminum battery racks.
What is it?
it forms large flakes of a white crystal like powder that eats the aluminum battery racks.
What is it?
QUOTE (paul h+Nov 9 2007, 12:04 PM)
A very common problem is battery acid dripping onto aluminum,
it forms large flakes of a white crystal like powder that eats the aluminum battery racks.
What is it?
My first guess would be Aluminium Sulfate.
Aluminium Sulfate forms by the reaction of Aluminium Hydroxide with Sulfuric acid, and matches the physical description.
Aluminium is generally protected by a thin layer of Aluminium Oxide, but I believe that the Aluminium Oxide can/does react slowly with sulfuric acid (for the same products), also, in the presence of water aluminium oxide can react to produce aluminium hydroxide, and aluminium itself, once you get past that protective oxide layer is very highly reactive - so there's possibly two or three different mechanisms occuring, all of which result in the production of Aluminium Sulfate - the white stuff you see.
it forms large flakes of a white crystal like powder that eats the aluminum battery racks.
What is it?
My first guess would be Aluminium Sulfate.
Aluminium Sulfate forms by the reaction of Aluminium Hydroxide with Sulfuric acid, and matches the physical description.
Aluminium is generally protected by a thin layer of Aluminium Oxide, but I believe that the Aluminium Oxide can/does react slowly with sulfuric acid (for the same products), also, in the presence of water aluminium oxide can react to produce aluminium hydroxide, and aluminium itself, once you get past that protective oxide layer is very highly reactive - so there's possibly two or three different mechanisms occuring, all of which result in the production of Aluminium Sulfate - the white stuff you see.
Thank you, 
I knew the hippie chemist would know what it was.
(but your to young to be a real hippie)
I have told people to hose it off and use baking soda to remove it but that only slows it down, when it gets too bad the aluminum has to be replaced. It's like termites on wood.
I knew the hippie chemist would know what it was.
(but your to young to be a real hippie)
I have told people to hose it off and use baking soda to remove it but that only slows it down, when it gets too bad the aluminum has to be replaced. It's like termites on wood.
QUOTE (paul h+Nov 11 2007, 12:09 PM)
Thank you,
I knew the hippie chemist would know what it was.
(but your to young to be a real hippie)
I have told people to hose it off and use baking soda to remove it but that only slows it down, when it gets too bad the aluminum has to be replaced. It's like termites on wood.
Yeah, and unfortunately, that's the best you're ever going to be able to do.
The only thing that's even remotely possible (AFAIK) would involve using a sacrificial metal, but all of the sacrificial metals that I can think of would probably cause more problems then they solve - for example, you could bolt a block of magnesium to the aluminium, and, essentially, the magnesium would act to preserve the aluminium by reacting itself, but, the Magnesium needs replacing (regularly) which I imagine would get expensive quickly, and not only that you have all the inherint risks of having magnesium in a hot, sometimes wet environment. Not only that, but I can't promise that the difference in reactivities between Aluminium and Magnesium is enough to do this effectively. Of course, there's also Lithium, Potassium, Sodium, and Calcium, but I know I don't need to go into detail as to why using these would be a very very bad bad bad idea...
I knew the hippie chemist would know what it was.
(but your to young to be a real hippie)
I have told people to hose it off and use baking soda to remove it but that only slows it down, when it gets too bad the aluminum has to be replaced. It's like termites on wood.
Yeah, and unfortunately, that's the best you're ever going to be able to do.
The only thing that's even remotely possible (AFAIK) would involve using a sacrificial metal, but all of the sacrificial metals that I can think of would probably cause more problems then they solve - for example, you could bolt a block of magnesium to the aluminium, and, essentially, the magnesium would act to preserve the aluminium by reacting itself, but, the Magnesium needs replacing (regularly) which I imagine would get expensive quickly, and not only that you have all the inherint risks of having magnesium in a hot, sometimes wet environment. Not only that, but I can't promise that the difference in reactivities between Aluminium and Magnesium is enough to do this effectively. Of course, there's also Lithium, Potassium, Sodium, and Calcium, but I know I don't need to go into detail as to why using these would be a very very bad bad bad idea...
Actually the aluminum is sacrificial, ( very cheap) not to mention profitable when the replacements is needed. I just didn't know for sure what the slime was. I know what causes it, (the leaking batteries) and how to prevent it, (don't over fill the batteries) and how to repair it, if they didn't heed my warnings about over filling.
BTW, A cute story. About a month ago a lady told me that she keeps forgetting to but distilled water to use to fill her batteries. but her friend told her that all she had to do was to boil a gallon of water on the stove and then put 2 tablespoons of salt in it.
I have to wonder how long those batteries are going to last. If they don't just fail to take a charge, I can see them getting so hot that they warp the plates inside and explode.
Ding bats,,, you gota love um.
BTW, A cute story. About a month ago a lady told me that she keeps forgetting to but distilled water to use to fill her batteries. but her friend told her that all she had to do was to boil a gallon of water on the stove and then put 2 tablespoons of salt in it.
I have to wonder how long those batteries are going to last. If they don't just fail to take a charge, I can see them getting so hot that they warp the plates inside and explode.
Ding bats,,, you gota love um.
In this context, sacrificial metal means something different.
In this context, a sacrificial metal is, more or less speaking, one that reacts preferentialy over another. Essentialy it's sacrificing it's electrons to protect the other metal, hence 'sacrificial'.
An example of this is galvanized nails - the Zinc is there to protect the Iron/steel nails, true of anything that is galvanized. Another example is in shipping, they bolt blocks of Zinc to the underside of the ship (Actually, I think it might be on the inside of the ship) to protect the steel of the ships hull from oxidation. It's a nifty little trick that uses well established technology.
Another example of this sort of chemistry is when we put an Iron nail in Copper sulfate solution - the iron of the nail reacts with the copper ions in solution to result in the deposition of copper on the nail, and the nail itself appearing to dissolve.
Again, in this case, the Iron is sacrificing it's electrons to the copper.
In this context, a sacrificial metal is, more or less speaking, one that reacts preferentialy over another. Essentialy it's sacrificing it's electrons to protect the other metal, hence 'sacrificial'.
An example of this is galvanized nails - the Zinc is there to protect the Iron/steel nails, true of anything that is galvanized. Another example is in shipping, they bolt blocks of Zinc to the underside of the ship (Actually, I think it might be on the inside of the ship) to protect the steel of the ships hull from oxidation. It's a nifty little trick that uses well established technology.
Another example of this sort of chemistry is when we put an Iron nail in Copper sulfate solution - the iron of the nail reacts with the copper ions in solution to result in the deposition of copper on the nail, and the nail itself appearing to dissolve.
Again, in this case, the Iron is sacrificing it's electrons to the copper.
QUOTE (Trippy+Nov 11 2007, 02:04 AM)
In this context, sacrificial metal means something different.
In this context, a sacrificial metal is, more or less speaking, one that reacts preferentialy over another. Essentialy it's sacrificing it's electrons to protect the other metal, hence 'sacrificial'.
An example of this is galvanized nails - the Zinc is there to protect the Iron/steel nails, true of anything that is galvanized. Another example is in shipping, they bolt blocks of Zinc to the underside of the ship (Actually, I think it might be on the inside of the ship) to protect the steel of the ships hull from oxidation. It's a nifty little trick that uses well established technology.
Another example of this sort of chemistry is when we put an Iron nail in Copper sulfate solution - the iron of the nail reacts with the copper ions in solution to result in the deposition of copper on the nail, and the nail itself appearing to dissolve.
Again, in this case, the Iron is sacrificing it's electrons to the copper.
I understood what you intended to say. ( Fire trucks use magnesium rods in the water tank to protect the steel tank, as do hot water heaters)
I was just trying to say (poorly, out of context) that the aluminum was so cheep that it would not be practical to design a way to protect it.
Any comments about the salt water in a battery? I do worry if I should have made a big deal out of it to protect her if they could explode.
Thanks
In this context, a sacrificial metal is, more or less speaking, one that reacts preferentialy over another. Essentialy it's sacrificing it's electrons to protect the other metal, hence 'sacrificial'.
An example of this is galvanized nails - the Zinc is there to protect the Iron/steel nails, true of anything that is galvanized. Another example is in shipping, they bolt blocks of Zinc to the underside of the ship (Actually, I think it might be on the inside of the ship) to protect the steel of the ships hull from oxidation. It's a nifty little trick that uses well established technology.
Another example of this sort of chemistry is when we put an Iron nail in Copper sulfate solution - the iron of the nail reacts with the copper ions in solution to result in the deposition of copper on the nail, and the nail itself appearing to dissolve.
Again, in this case, the Iron is sacrificing it's electrons to the copper.
I understood what you intended to say. ( Fire trucks use magnesium rods in the water tank to protect the steel tank, as do hot water heaters)
I was just trying to say (poorly, out of context) that the aluminum was so cheep that it would not be practical to design a way to protect it.
Any comments about the salt water in a battery? I do worry if I should have made a big deal out of it to protect her if they could explode.
Thanks
QUOTE (paul h+Nov 12 2007, 02:28 AM)
I understood what you intended to say. ( Fire trucks use magnesium rods in the water tank to protect the steel tank, as do hot water heaters)
I was just trying to say (poorly, out of context) that the aluminum was so cheep that it would not be practical to design a way to protect it.
Any comments about the salt water in a battery? I do worry if I should have made a big deal out of it to protect her if they could explode.
Thanks
Heh heh. >_>
Wow, didn't know that (about hot water cylinders, or fire trucks, but yeah, I get what you mean.
Generally speaking, I agree with you, I don't think that dumping table salt into a car battery is a good idea, but then at the same time, I'm not entirely sure that it would do any harm - you'll electrolyze the water itself to liberate Hydrogen and Oxygen before you affect the Sodium Chloride, in fact for all intents and purposes (in this case) the table salt can be considered pretty much chemically inert, the only effect I would really expect it o have, especially if it's only in small quantities would be to improve the batteries internal resistance.
But yeah, it isn't something I had ever heard of, it isn't something I'd do, and it isn't something I'd tell others to do, if you know what I mean?
I was just trying to say (poorly, out of context) that the aluminum was so cheep that it would not be practical to design a way to protect it.
Any comments about the salt water in a battery? I do worry if I should have made a big deal out of it to protect her if they could explode.
Thanks
Heh heh. >_>
Wow, didn't know that (about hot water cylinders, or fire trucks, but yeah, I get what you mean.
Generally speaking, I agree with you, I don't think that dumping table salt into a car battery is a good idea, but then at the same time, I'm not entirely sure that it would do any harm - you'll electrolyze the water itself to liberate Hydrogen and Oxygen before you affect the Sodium Chloride, in fact for all intents and purposes (in this case) the table salt can be considered pretty much chemically inert, the only effect I would really expect it o have, especially if it's only in small quantities would be to improve the batteries internal resistance.
But yeah, it isn't something I had ever heard of, it isn't something I'd do, and it isn't something I'd tell others to do, if you know what I mean?
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