Stuck Seat Tube

[Andy R]

I cant do that because the top of the tube has broken off inside of the frame so there is nothing left to grip :S

In that case, what I would do is saw though the seatpost (ie so that it is split) and then use a slide hammer with a hooked end that will effectively drive the seatpost out from below.

If you use a bit of ingenuity you can knock one up with some 12mm threaded bar, a piece of 2" dia. bright mild bar about 4" long with a 12mm clearance hole through it (a local engineering co. will do this for the price of a few beers !) and a few 12mm nuts.

 

[Corduroyboy]

Can't believe no-one has suggested caustic soda! (Well Iwasgoodonce hinted at it!)
Get some caustic soda. Mix up a strong solution. Strip the frame down, removing as many components as possible. Turn the frame upside down after sealing off the remnants of the seatpost. Slowly (and with rubber gloves on) fill the frame with the solution. Leave for a couple of days in a place where it won't matter if there is any leakage of solution. The aluminium post will literally dissolve (you might have to experiment with the strength of the solution, but BE CAREFUL - protect your skin and eyes!) Finally when the 'post has dissolved (or slides out), rinse the frame thoroughly inside and out. Fit new 'post (with grease). Build back up & ride, secure in the knowledge that you have saved a frame and only spend a couple of quid in doing so!

 

[Calorian]

Hey guys,

This idea may actually work That is to say i can do it on a budget.
I have infront of me a selection of chemicals
Sodium hydrogren Sulphate
Sodium carbonate
Sodium bicarbonate
Sodium Silicate
Sodium Thiosulphate

Also have table salt and bleach too

any ideas which one i should use? I think either SHS or SC

 

[Andy R]

I wouldn't think any of them would be much use.

If you're going to try the caustic soda method then it's sodium hydroxide you want (won't do any paint it comes into contact with much good though....)

 

[Calorian]

I thought that. Found some i think. My girlfriend found some drain cleaner and says its lethal. Just checked and yes its the stuff.

 

[Calorian]

Well. That was an interesting experience. After covering half the place in a mixture of photo developer and drain cleaner, ive decided to go back to the drawing board.

How does one go about sealing every whole on the frame?

I stripped it down to an extent, plugged the visibly large wholes but didnt take into account the smaller wholes (Screws and wholes on the tubes by the gears)

 

[Anthony]

Well. That was an interesting experience. After covering half the place in a mixture of photo developer and drain cleaner, ive decided to go back to the drawing board.
How does one go about sealing every whole on the frame?
I stripped it down to an extent, plugged the visibly large wholes but didnt take into account the smaller wholes (Screws and wholes on the tubes by the gears)

I'm sure you're not the first person ever to do that! Persistence pays dividends.

 

[Andy R]

I still think that I'd try and saw through the remains of the seatpost to split it and then devise a slide hammer to drive it out.

What length of post remains in the frame? If it's no more than 75-100mm you should be able to cut through that relatively easily with a padsaw or even with a bastard cut three square file (more rigid than a hacksaw blade obviously !)

Clamp the frame carefully in a workmate or something so the seat tube is a a comfortable angle to work on - it's not that bad a job (and you only have to do it once anyway )

 

[Calorian]

Hey there,

Ive started to dissolve the tube now. Ive got the bike hanging from the ceiling in my cellar with buckets underneath catching the drips.

Its very hard trying to seal all of the wholes so i have duct-taped them over which is slowing them down, its now just a case of re-filtering it through every time the frame runs dry

Due to the amount of space I have it looks like ill only be able to dissolve one side, but that should hopefully be enough to weaken the other side and then it should -hopefully- fall out.

Cheers for the help and ill let you know how it goes.

 

[cherrybomb]

I hope you cellar is well ventilated!