Removing stuck or seized seatpost?

I have a tip for you all Patio cleaner

40% hydrochloric acid the thing is it will convert/eat rust back to base metal

and the aluminium it will eat away , so everything is nice and clean inside your steerer or seat tube

Once it stops working replace it with fresh and pour the rest away

Interesting... But hydrochloric acid also reacts with steel.

Got around to doing it, seatpost is half the thickness after 2 wilko bottles of soda. Think I messed up the mixing or didn't give it long enough in the tube but another £4 of soda and I should be good. Minimal paint damage so far just a bit by the top of the seatpost so I should be able to patch it up or just cover it with a sticker.

It's going well(ish) 4 bottles of wilko caustic soda down, next one should do it but I'm out again so another tomorrow. Paint damage is minimal, that slight faded orange bit on the supreme sticker and the paint above the welds feels flatted back but could I think be saved if I just lacker over it, couple of bits gone past the paint but fingers crossed I can touch it up after and it won't show so much.

It's only as thick as some card but it's fused to the frame and won't move, can't get a grip to fold it in on itself or anything.

Seems to be a bit better after some more caustic soda but I think I'm mixing it in the wrong ratio and just wasting lots of it. Getting slightly better each time but still not great. I can now bend the exposed bits easily but it's properly fused together so won't bend away, more soda.

I invented a Seatpost Extractor tool after trying all of the Sheldon Brown home remedies ---- none of which worked for me.

http://www.seatpostextractor.com

If you are selling stuff sell it in the classifieds.

Another method for unseizing a post, this time with a slide hammer, not seen this tried before so thought it might be of use to someone here...

http://youtu.be/S3ek2GeZzE0

That's very promising! Off to eBay to get me a slide hammer

If you find a reasonably priced one let me know, I looked and only found light weight ones for pulling dents out of metal work....

I've been ringing around and scouring eBay for heavy ones and they're all pretty expensive.

Decided I'm going to make one out of scrap metal. I've got the means to weld something up and I've got some nice bits of clean metal for the job so will have a go at it hopefully this week. Will make it bike specific too. If it works out I'll see about making more. I've designed it all in my head just need to go do it

Nice idea.

Nice one, keen to see what you knock up! Maybe create a thread for it on the projects thread...

This is brilliant... another method which could be applied to the dreaded stuck seatpost issue:

http://youtu.be/7GvN7w386U0

No way, I was looking at one of those ratchets today in a motor factors thinking about this. About half way done on the slide hammer btw, hopefully have a working example by the end of the week. Been really motivated by that video!

Haha, well great minds think alike.... I love that guy, you got to admire the effort he goes to. Good work on the slide hammer, when it's done I have the perfect test subject, a Charge Plug with seized aluminium post.

Same same, ive got about 3 seized seat posts, a seized stem and seized crank, all of which I intend to get out.

If this thing works you're welcome to have a go with it but I'm down in Brighton

just tried my home brew slide hammer. didnt work...

i made the weight out of concrete and it just ended up cracking and falling apart. plus the post didnt budge despite giving it enough wallop to smash up the concrete.

will try a metal weight if i can find one and try again

Yeah I was thinking the other day what to make the hammer part from and thought a couple of iron weights from a small dumbbell set would do the trick... Something like a couple of these:

1 Attachment

try PLUSGAS - brilliant stuff

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjEpLSBw6PNAhVD7xQKHT_FBocQFghMMAE&url=https%3A%2F%2Fwww.amazon.co.uk%2FEnglish-Abrasives-809-10-Plusgas-250ml%2Fdp%2FB0001P02S4&usg=AFQjCNHMjbVtb6GwqBFuvq4VjfORGL7_Cw&sig2=pRBfKJsBjCqIZs5QUnQXsw

Yeah, Plusgas or Liquid Wrench are the best, you can buy a 400ml aerosol can of Plusgas on the bay for just £5...

Any ideas how to make a diy plug for seatpost end? Post internal bore is elliptical. It's an anodized alu post galvanised in a 4130 chromoly frame by using lithium grease. Gonna try pour plusgas into the bb shell and leave it to work before attempting any damaging methods

Clingfilm over the end held in place by rubber band.

Cheers, tried that but penetrating fluid either by its intended purpose or sheer volume/pressure leaked out all over the place. Honestly feel like repeatedly bludgeoning my head against a wall would be the best option now. New frame, new post, head melted

I used Blu-Tac I think.