Bike Forums - View Single Post - caustic lye and alloy (last time I ask this, I swear)

10-20-07, 05:41 PM

#10

cyccommute

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Quote:

Originally Posted by tcpasley

I wouldn't even think of trying to dissolve the seat post out of the seat tube. As cyccomute says, keeping the base solution in contact with the seat tube would be difficult unless you wanted to dip the frame upside down in a tub of strong base.

The reaction equation posted by cyccomute appears to be an overall equation for a multistep process, with base and acid steps. Strong bases like KOH by themselves will react with aluminum metal without the acid (the H2SO4 in the equation) to make, for example, KAl(OH)4, which is soluble.

Oops

I gave the reaction for making alum from aluminum. KOH reaction with the aluminum is the first step and it's the one that makes hydrogen. The sulfuric acid isn't needed at all. Sorry.

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