Removing stuck or seized seatpost?

Don’t know what @Scrabble used but I went with a whittled down wine cork

Hmmm, can't remember if i'm honest. Perhaps some tape and then supported by an old rag stuffed in the BB shell. Do remember that i was worried it would all just leak out, but in the end whatever I did was fine.

I got this when I was a teenager from someone. Thought I’d see what they had to say about seatposts.

2 Attachments

Finally. Bastard.

2 Attachments

Has anyone tried a hammer drill on a seat post?

I have but it didn’t do anything. If anything it would push it in. Tried an sds drill with a chisel to push a seized post out. Wouldn’t budge though. Only drill thing I’ve had work is to simply drill it out. It takes ages and gets hot easily. Do was lots of short sharp bursts with the drill. Slow speed high pressure for about 5 seconds. Cutting fluid and a wet towel wrapped around the seat tube as paint was burning. Helps to draw the heat away. It’s like a last ditch attempt but never fails. Takes hours, usually need to hook the last bit out, and need to clean swarf out of the frame. Not ideal but gets the job done.

An insight from my recent NaOH experience is that to really make things happen you need to mix the stuff up and use it right away while it’s still hot, this will produce the volcano effect visible in @Scrabble ‘s gif from last page and will also heat the seattube to the point where water sizzles when you pour it on the outside of the frame. In my case the bright yellow paint turned orange for a bit but paled to yellow again once it cooled down.

Would be very interested to see the paint cleaned up post sizzle please? I'm tempted to go down this route to remove a firmly stuck seatpost but I really dont want to lose any paint.

I was very cautious at first but lost patience when it took so long and decided to just make the solution as aggressive as possible to get the damned post out. You can see where the lye ran and ate through the paint. I suppose a careful masking/plastic film job could have saved the paint.

Or send it to a 'seatpost man' to get it out clean as a whistle...£80 + postage though

Thanks, looks like you did a top job paint really not that bad, could be touched up quite easily! 👍

Yeah thanks for the suggestion have seen some videos of custom seat post pullers that would make quick work of the job! Would prob be £30 postage each way on top of the £80 so I have ordered some caustic soda for £7 🤞

I’m no chemist but temperature seemed to be the controlling factor. When it got violent I’d spray some water on the seattube and everything would calm down a bit. I think if you’re willing to spend all day watching over it you might be able to keep it bubbling at just the right level without spilling over.

Have watched Facebook videos of people using hammer drills, on the hammer setting, with a modified bit with a socket on the end to vibrate seized nuts or Then this frees the nut/bolt to be unscrewed.

Hence the idea that forcing the seat post to move down will break the corrosion so I can remove the seat post by twisting or pulling.

My a level chemistry, from more than 2 decades ago, say the reaction is exothermic. So reducing the temperature impedes the reaction.

I liked the idea, but in my head it said impact drive with modified socket to latch onto a bar drilled through the post (with pulling leverage from the bar with rope), if it's a 1/2" mechanic's impact driver then it may stress the seat cluster but it's all a game of risk

It may well work. I guess it just depends how much post is stuck in the frame and seized it is. If you can get it to move even a tiny bit then you can get it out, in my experience. Good luck with it.

Have tried something similar with a stem stuck in a fork and a 12v wheel bolt gun and bolt remover. Just twisted the forks.

Be afraid to damage the frame.

Well if no one has tried I'll give it a go with an shitty socket and the seat post.

Dolly says it’s not coming out, but being carbon it will drill out easily.

1 Attachment

I've never seen a more sincere dog

Haha! If you listen carefully you can hear she is saying “well you’ve fucked that”

Isn't it you made a dog's dinner of that.

rep

Have to say I found the caustic soda route disappointing, partly due to my own inability to stop the solution running out of the frame and once I did keep it contained seemed to have limited impact on the seat post despite bubbling & smoking like a chimney at times.
I even left it over night. I’m sure if I kept going it would eventually dissolve but probably just as cheap to take it LBS and burn it out.