Caustic Soda - no reaction

Tolsey31

Retro Guru
Hi,
I tried the caustic soda to remove a mangled seatpost but didn't get the reaction I was expecting...nothing happened. It's an alu seatpost in steel frame. I didn't have it open to the elements so I'm thinking that oxygen may be a part of the reaction? Anyone with the science chops for this please?
 
NaOH will react with aluminum, guaranteed. There are some things that will quell or prevent such reaction; oil, grease, wax, anodize coatings, paint, residual oxides, weak NaOH solution, etc.

Is there adequate accessibility to scuff the inside of the post and hit it with degreaser?
 
It's pretty mashed up inside the tube - maybe the solution wasn't strong enough - I used about 70g soda to 0.5l water.
 
Pile a load of the crystals up around the post etc and get some boiling water, poor some of that on it slowly.

Take whatever precautions you need after a few beers in the sun while you do it.
I'll leave you to the risk assessment.
 
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