caustic soda to remove stuck seatpost done to death .....

[02gf74]

... but what do you do if you have steel broken or stuck in an aluminium frame?

Useful to know about this.

If you have an aluminium frame and have stuck broken steel bolt in it, this describes how to get jiggy with (safe) chemicals and SCIENCE to dissolve it out.

And how it was done described here.

 

[Raging_Bulls]

Re: caustic soda to remove stuck seatpost done to death ....

steel post in alu frame? Caustic soda will solve that as well. You'll need a bit more soda, but in the end you'll still have a usable post.

Joking aside, alu expands more than steel. Put the frame in an oven and it'll be easier as long as you wear something to protect your hands from the heat.

 

[HypnoToad]

Re: caustic soda to remove stuck seatpost done to death ....

How long does an Alu seatpost take to dissolve to those on here that have tried it?

Using heat is a nice method, maybe a hairdryer would be a little easier than a cooker?

 

[kingoffootball]

Re: caustic soda to remove stuck seatpost done to death ....

It took a couple of hours for the aluminium seat post to be completely gone when I did it, using 1kg of caustic soda dissolved in about 2ltrs of water, adding more solution periodically.

 

[HypnoToad]

Re: caustic soda to remove stuck seatpost done to death ....

Nice, I've been mixing small amounts and so far have used around 500g or so, and its slowly doing its thing. I do find it gets pretty hot, and didn't want to risk damaging the frame but even so I'm going to try a stronger mix, thanks

 

[kingoffootball]

Re: caustic soda to remove stuck seatpost done to death ....

I've replied on the other thread, but it won't get hot enough to damage the frame. (But it does get hot enough to burn you, so that's another danger to be aware of).