Any advice about using caustic soda to remove an aluminium seatpost from a steel frame?

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Midnight
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Re: Any advice about using caustic soda to remove an aluminium seatpost from a steel frame?

Postby Midnight » Tue Jul 09, 2019 16:04 pm

PhotoNic69 wrote:Caustic soda is really nasty stuff. I've used it quite a bit around the home. You are likely to strip the paint off your frame before the post dissolves.

Have your tried Coca-Cola? (Other brands are available). Fill tube repeatedly with this for a few days . The citric acid should dissolve a lot of the corrosion. My dad used coke on a 150 year old Spanish pistol he found buried in mud. Three days later he got the firing pins to move!!



I use 17p 1l cola from tesco for rust removal, works a treat

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The Rookie
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Re: Any advice about using caustic soda to remove an aluminium seatpost from a steel frame?

Postby The Rookie » Wed Jul 10, 2019 09:40 am

If you read Sheldon Brown he suggests ammonia, much less likely to cause life changing injuries and works really well. It dissolves the aluminium oxide that usually causes the jamming with aluminium components.

Bonzo Banana
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Re: Any advice about using caustic soda to remove an aluminium seatpost from a steel frame?

Postby Bonzo Banana » Sun Jul 14, 2019 14:39 pm

I've just got back from the hospital today. No, actually that is probably a future event. I tried the extra weight on the slide hammer and it despite the much greater impact over the standard slide hammer it still would not budge. It feels like in other circumstances that might be sufficient but not here sadly. I will try the chemical approach soon. Just building up the nerve or something.

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Alejandrosdog
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Re: Any advice about using caustic soda to remove an aluminium seatpost from a steel frame?

Postby Alejandrosdog » Sun Jul 14, 2019 17:06 pm

Make sure you live stream it and give us plenty of notice :)

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darkhairedlord
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Re: Any advice about using caustic soda to remove an aluminium seatpost from a steel frame?

Postby darkhairedlord » Sun Jul 14, 2019 19:53 pm

Why are you removing it? Apart from now its completely wrecked?

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darkhairedlord
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Re: Any advice about using caustic soda to remove an aluminium seatpost from a steel frame?

Postby darkhairedlord » Sun Jul 14, 2019 19:55 pm

gaanrowl wrote:
Franco di Banco wrote:Cut the seat post across, leaving an inch or so protruding from the top of the seat tube. Then get a hacksaw blade in a holder, or a dirty rag, and keep running that up and down inside the remaining seat post. Keep it parallel to the post/tube and eventually you will cut through the seat post. Then grab hold of the protuding bit with pliers, wrench or vice and the post should twist out.

No need for all those chemicals and the milennials protective clothing. Won't take any longer than your way. You can always make two opposing cuts and then the two halves of the post can be knocked out. Just takes a bit longer.



Recently used this method to remove a thompson Masterpiece :cry: from my Ritchey frame. once the vertical cuts were made i used a thin piece of wood and knocked it in between the frame and seatpost, this split the alloy and it came out easily.

Did it split the frame or the post?

Bonzo Banana
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Re: Any advice about using caustic soda to remove an aluminium seatpost from a steel frame?

Postby Bonzo Banana » Mon Jul 15, 2019 09:55 am

darkhairedlord wrote:Why are you removing it? Apart from now its completely wrecked?


I bought the bike off ebay for 99p auction, it's a sort of early hybrid design and want to convert it to a touring bike. It has a high quality freehub based drivetrain and strong 26" wheels and the frame seems absolutely ideal for what I want it's just the saddlepost is stuck and too high for me. Even if they had said the seatpost was stuck I would have bid for it, they did warn it hadn't been used for years but was in generally good condition for its age. It looked like a bike that had seem minimal use but hadn't been stored in ideal conditions. I'm trying to make myself a Thorn 26" wheeled style touring bike on the cheap.

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darkhairedlord
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Re: Any advice about using caustic soda to remove an aluminium seatpost from a steel frame?

Postby darkhairedlord » Mon Jul 15, 2019 11:29 am

Bonzo Banana wrote:
darkhairedlord wrote:Why are you removing it? Apart from now its completely wrecked?


I bought the bike off ebay for 99p auction, it's a sort of early hybrid design and want to convert it to a touring bike. It has a high quality freehub based drivetrain and strong 26" wheels and the frame seems absolutely ideal for what I want it's just the saddlepost is stuck and too high for me. Even if they had said the seatpost was stuck I would have bid for it, they did warn it hadn't been used for years but was in generally good condition for its age. It looked like a bike that had seem minimal use but hadn't been stored in ideal conditions. I'm trying to make myself a Thorn 26" wheeled style touring bike on the cheap.

Nice, pics soon i hope.


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