Stuck seatpost - Caustic Soda after Penetrating Oil?

Discuss light weight issues concerning road bikes & parts.
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iamalex
Posts: 215
Joined: Sun Oct 30, 2011 5:25 pm
Location: London, UK

by iamalex

For £65 I thought a Serotta built steel frameset with a stuck seatpost was worth trying to save. It's Spirit steel with an alu post. I turned upside down, plugged holes and filled the seat tube with penetrating oil and soaked for a day and a half. It's still stuck solid though did get about 5mm rotation before snapping the top of the post off. The next step would be to corrode it out using caustic soda - I've picked up goggles and overalls.

Any scientists out there - Is the heat from the caustic soda reaction likely to cause the penetrating oil residue inside the frame to combust??

Thanks
Last edited by iamalex on Sun Aug 04, 2013 7:56 am, edited 1 time in total.

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LEC135
Posts: 156
Joined: Wed Jun 08, 2005 4:29 pm
Location: London

by LEC135

There is another sort of 'caustic soda' to try first and thats Coke. Let that eat away at it for a few days. Worked for me.

by Weenie


vfb
Posts: 58
Joined: Thu Oct 07, 2010 7:35 pm
Location: Denmark

by vfb

I havent tried it my self, but i have heard that cola could do the job with a seatpost stuck in the frame. Turn the frame upside down, and fill the cola inside the frame and give it around 24 hours, and try again.

Hope it helps and good luck, and :thumbup: for trying to save a nice frame :-)
I ride for fun

Paniagua
Posts: 13
Joined: Mon May 27, 2013 8:16 am

by Paniagua

A lot of "mechanical" solutions before going Caustic, but really time and patience are your friends, re-applications of a thin penetrating oil (mineral oil for bad cases) over time (more than a couple days, maybe a week or even more) This works, something I do for all kinds of "stuck" situations.


iamalex
Posts: 215
Joined: Sun Oct 30, 2011 5:25 pm
Location: London, UK

by iamalex

Thanks for the suggestions - I think I've got plans A, B and C now!
The frame's continued to soak in penetrating oil for another night so later today I'll give it hell with a pipe wrench. (before toping back up with oil I expect).

Turned into a bigger job that I anticipated but not looking to back down now. Cranks seized to bottom bracket, bottom bracket seized in frame. Penetrating oil + old mtb handlebars attached to huge spanner for leverage + a few hours did the job on those.

The frame is a Glider Tupelo, built by Serotta for the bike shop Cycle Fit in London a few years back. I'll get some pics of mine at some point but here's a nice one from the internet.

Image

Monkeyboy3333
Posts: 632
Joined: Tue Apr 05, 2011 7:41 pm

by Monkeyboy3333

I'm sure it will be worth it , patience allowing!

by Weenie


Monkeyboy3333
Posts: 632
Joined: Tue Apr 05, 2011 7:41 pm

by Monkeyboy3333

would chucking it in a walk in freezer do anything? I'm thinking expansion and contraction here....

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