Pesky Stuck Seat Post

[Gravity Aided]

Hello,

Thanks for the help so far. I spent 3 hours or so this evening (plus a few hours over the past few days) trying to free this up, but have come to the conclusion its well stuck. So I will go down the caustic route. Wish me luck....

PS. Why are these seat posts so thick! My modern bike is maybe 2mm alu, this thing is probs near on 10!

Do be careful with the caustic, quite the mess maker that. Couple of YouTube video out there on it,fun to watch.

 

[lpretro1]

Send it to:
John Lee (The Seatpost Man)
JWL Design
Chorley
Lancs
UK
Email john@theseatpostman.com
Phone 07539474088
Website www.theseatpostman.com
Facebook https://www.facebook.com/theseatpostman1
Have used him several times and he is brilliant

 

[Gravity Aided]

View: https://www.youtube.com/watch?v=-dYnSVVDxrE

Sort of how I remember it going.

 

[RyanW]

Both me and my other half are trained chemists (of a fashion(Biochemists)) so hopefully we will be okay. I have used far nastier chemicals in my time then caustic (Evil Laugh).


I will try and get it on video to show the result, however the estimates are .5mm of alu per 24h and this thing is around 10mm so nearly 20 days (This is based on someone else's calcs not mine) so we will see how we go.

My fear is i can see two small cracks at the bottom of the cut for the seat post which i intend to drill ou to stop spreading. However any more physical force may make them worse.

Whats more frustrating is I managed to strip the rest of the bike in about 10 minutes as everything else had been so well lubed when made and never really ridden in 30 years.

Only thing I cannot work out is how to remove the locking washer? on the headset to get the forks off.

Ideas on a post card please.

 

[raleighnut]

If it's a standard Raleigh headset with a serrated lock ring just undo the top nut and it lifts off, but problems arise if someone has turned the bottom nut (to tighten the bearings up) without removing the serrated ring, the little tag that stops the lock ring rotating will have been forced out of the slot in the fork. what you need to do is to undo the bottom race nut until the tab lines up again with the slot and then it should lift off.
That problem is quite common on the serrated head set as people just slacken the top nut and blithely turn the bottom nut without realising that the lock ring locates into the slot on the fork, they just force it round.

 

[Gravity Aided]

I think the reaction will go faster, It took just 4-5 hours the one time I saw it done. I think it took the fellow in the video 3-4 batches to get it done. But that price is negligible, compared to saving a frame. Good luck, be safe.

 

[Plumster]

If the BB is out, seal the hole in the bottom of the seat tube, then you will only be filling that with caustic. If you just use a dob of silicon sealant, you can pull it out after

 

[RyanW]

If the BB is out, seal the hole in the bottom of the seat tube, then you will only be filling that with caustic. If you just use a dob of silicon sealant, you can pull it out after

Didnt think if the silicone. Good plan. I have just used some old inners so far.

 

[RyanW]

Just thought I would provide an update. Started it yesterday at around 1pm. I have gone for the slow and steady rather then mt Vesuvius approach (Boring I know!) so I filled the tube up with a 100mg/500ml solution and have been topping up as it goes down with a 50g/100ml~ solution (No idea where its going, its either gassing off, or filling up something else!). The control im using (The cut of seat post head) has just about lost all its marking which I make around 1mm~ deep, so I guess that's the rate I'm looking at, so hopefully this time next week it should be nearly out.

My dilemma is, do I give it a few more days (Say Wednesday) and empty it to see if it now budges, or just leave it going. I have not seen anyone else trying to get a seat post this thick out with this method.

I'm hoping as the diameter gets bigger (as its gets dissolved) the rate should slowly go up (greater surface area) so it should start to go a bit quicker, but I guess I will need to top up more. My plan is to top up each morning and each afternoon.

So far I'm not dead, so I think its going okay.

 

[RyanW]

So I thought I would give an update. This is the 1 week progress (well, 6 days really.)

The process has been fine. Empty and top up every day with a solution of roughly 100mg/500ml apart from when i cannot be bothered and I just add the 50/100 as a top up.

Only issues that I have had is that now and again the plug falls out so I lose the solution and have to come up with a new way of sealing (Normally a rubber glove with something shoved in roughly the size of the hole to keep it in(No Jokes))

As you can see the top has been eaten away quite a bit, but it has not gone all the way down, its slowly getting there. Tomorrow im getting some silicone sealant as I think this will be the best way to plug now(As it has eaten enough to now go down the top tube.

Hopefully one more week, maybe less and it will be out.

Downside so far .. I keep getting the stuff on me and its not pleasant (light splashes when moving it) and it has damaged the paint, so I will need a respray.


Cost : £7 on caustic soda, £1 on the tape.

 

[ChrisEyles]

Good work - it's gonna be *so* satisfying when you get that one out

 

[RyanW]

Might put a bottle of bubbly in the fridge to get ready to celebrate! Probably wont be able to get the cork out though

 

[DaveReading]

+1 for PlusGas (see what I did there).

 

[RyanW]

Good work - it's gonna be *so* satisfying when you get that one out

It was better then I ever imagined.

THE DAMN THING IS OUT...


Only problem now, I need a new paint job, lower headtube race, and Raleigh Badge (I could not get the badge off, it disintegrated and seems to have taken the race with it)


But


ITS OUT!!!!!!!

 

[Gravity Aided]

Congratulations , well done.