rudy090992
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HF and a shovel
I have a piece of sand (SiO2 + impurities) that is keeping a very expensive collapsible ski shovel from collapsing. I believe the shovel is made of
stainless steel.
I have tried everything include lubricants and heating.
Heres my idea. I'm going to do everything outside.
Fill the crevice containing the piece of sand with as much toothpaste(NaF) as possible. Then soak the whole shovel in H2SO4 solution. Then try to
collapse the shovel. Once it collapses, neutralize everything with sodium carbonate solution.
Comments? Ideas?
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rudy090992
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Actually I'll just dissolve an equimolar amount of naf from toothpaste in h2so4 and then add the shovel.
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White Yeti
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There probably isn't enough sodium fluoride in toothpaste to get the job done. I would use HF directly. HF is sometimes used in rust removal
compositions. Be very careful with it though. All soluble fluoride salts are hazardous, HF is especially so, because it diffuses though skin rapidly
and painlessly. Once you're done, you may also want to precipitate out the fluoride by adding calcium carbonate. The CaF2 formed is reasonably
insoluble in water to handle safely.
"Ja, Kalzium, das ist alles!" -Otto Loewi
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rudy090992
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Quote: Originally posted by White Yeti  | | There probably isn't enough sodium fluoride in toothpaste to get the job done. I would use HF directly. HF is sometimes used in rust removal
compositions. Be very careful with it though. All soluble fluoride salts are hazardous, HF is especially so, because it diffuses though skin rapidly
and painlessly. Once you're done, you may also want to precipitate out the fluoride by adding calcium carbonate. The CaF2 formed is reasonably
insoluble in water to handle safely. |
Hmm Ill look into that. There is 0.245% F in toothpaste. a thing of toothpaste weighs about 300g. I only need to dissolve one or two grains of sand.
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Hexavalent
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Not being funny, but have you tried rinsing and shaking with good ol' water?
I can't be sure about its reaction with the other metals in stainless steel, but perhaps sodium hydroxide solution or even the molten solid would be
another idea.
[Edited on 24-11-2012 by Hexavalent]
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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blogfast25
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The amount of NaF in toothpaste is negligible. It would poison you otherwise.
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Pyro
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I think hex is onto something, shove as much NaOH into the space as you can, then melt with a torch, then put the shovel in water to dissolve the NaOH
all above information is intellectual property of Pyro.  |
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Sedit
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I think you would have much better chances with Phosphoric acid. It dissolves SO2 slowly and would handle the rust. Plus its much easier to acquire
and handle then a deadly poison.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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blogfast25
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| Quote: Originally posted by Sedit | | I think you would have much better chances with Phosphoric acid. It dissolves SO2 slowly and would handle the rust. Plus its much easier to acquire
and handle then a deadly poison. |
I presume you meant to write 'SiO2' and not SO2.
Phosphoric acid slowly dissolves SiO2??? Do you have any evidence for that? What would be the reaction products (assuming that dissolution is indeed
reactive)?
[Edited on 24-11-2012 by blogfast25]
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bfesser
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Tap on it with a rubber mallet until it comes loose, or use a aluminum pop can shim to push the sand grains out. Chemistry is not always the answer.
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bahamuth
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| Quote: Originally posted by blogfast25 | | Quote: Originally posted by Sedit | | I think you would have much better chances with Phosphoric acid. It dissolves SO2 slowly and would handle the rust. Plus its much easier to acquire
and handle then a deadly poison. |
I presume you meant to write 'SiO2' and not SO2.
Phosphoric acid slowly dissolves SiO2??? Do you have any evidence for that? What would be the reaction products (assuming that dissolution is indeed
reactive)?
[Edited on 24-11-2012 by blogfast25] |
I doubt phosphoric dissolves sand at any appreciable rate at RT or below, but it indeed does dissolve glass/quartz at elevated temps, ruined my
tabletop Schott Ceran cooking stove while using boiling phosphoric acid to remove rust. (edit)
Additionally we used it to dissolve ultra pure quartz for isotope analysis at the quartz refinery I used to work.
But to comment on the OP, use water and wriggle it loose, there will be a lot of pain to try to dissolve any sand with acid/base. Knock it with a
hammer to crush the sand grains even, better than dealing with corrosives.
[Edited on 24-11-2012 by bahamuth]
Any sufficiently advanced technology is indistinguishable from magic.
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