Caustic soda on stuck BB

[Tc]

Re: Re:

managed to get a stuck xt bb out of a steel rocky last month. Caustic soda soak over a few days. worked a treat. be careful though its dnagerous stuff. all done outside, glasses gloves used. dissolved the all alu parts.

I did a seatpost recently & it was immensely rewarding & what I did learn was not to tape the paintwork up to protect it as the tape acts as lagging & combined with the chemical reaction heat damages the paint more!

 

[Rampage]

Remember it will permanently blind you if it gets in your eye!

Use safety glasses and a face mask as a minimum. I've had things splash under safety glasses before.

 

[dr nick]

Re:

And it burns your skin too! And gives off what I believe is hydrogen so use it somewhere well ventilated.

I removed a stuck seatpost and stem with the kids helping! Lots of safety kit was involved. Over two weeks we used gradually stronger and stronger concentrations. Worked a treat. Remember DO try this at home kids (but wear safety kit...)

 

[hamster]

It doesn't give off hydrogen, typically something far worse like alkali fumes which attack lungs too.

 

[kingoffootball]

Hydrogen is released, the formula for the reaction is:

2Al + 2NaOH + 2H2O → 2NaAlO2 + 3H2

But given it's not pure aluminium there will be other, probably more hazardous gases released. Having said that, I breathed them in and I'm still alive:

https://www.youtube.com/watch?v=-dYnSVVDxrE

FluffyChicken could probably be more accurate with the chemistry of it.

 

[hamster]

Oops my mistake. The hydrogen is probably the least of your problems...

Reeds manual has it as 2Al+6NaOH -> 3H2+2Na3AlO3

 

[FluffyChicken]

Re:

Reeds manual wouldn't work very well as there is no solution. That is solid. There is water in this process.

I can tell you what happens with solid sodium hydroxide and aluminium powder down a sink and then add a bit of water.


You can hardly breath and choke in the room (a quitr large one at that) either from rapid hydrogen generation of aluminium powder ejected into the air at a rapid rate.

And it's a bugger to get it out of the air and the dust lingers for quite a few hours.

Not fun.
Really your lungs feel like they lock themselves up. And that was only a small quantity.