Stuck seatpost (another) and ammonia?

[gerrymcm]

Has anybody had any success using amonia to free a seized alu seatpost in a steel frame?

I have one that is well and truly seized and before I attempt to make a reamer from a flat wood bit, as suggested by Colin531, or try cutting it out with a home made hacksaw blade holder, I'm wondering how successful ammonia is or can be?

I'm assuming that there needs to be an entry point for the amonia to work, i.e to actually get in between the seatpost and seat tube?

It's a butted frame so I'm assuming that at the bottom of the seatpost, inside the seat tube, there will hopefully be a small gap so if I inverted the frame, plugged the seat post and filled the seat tube with ammonia it would then have an entry point?

Should I just just pass on the ammonia and go straight to cutting/reaming?

Any ideas or comment or advice gratefully accepted.

** Edited to rectify my spelling

Thanks
Gerry

[mercalia]

where in fact do u get the "ammonia" from any way? that isnt bleach? or is it?

[gaz]

.

[gerrymcm]

"Ammonia" available here
http://www.robertdyas.co.uk/homecare-es ... onia-500ml
I guess there are different strengths however I'm not sure what this.

Gerry

[gerrymcm]

Thanks Gaz.

[andrew_s]

viewtopic.php?f=5&t=90380&hilit=sodium+hydroxide

Summary: ammonia isn't strong enough

[gerrymcm]

Andrew
Thanks for that link it's made up my mind that before I start cutting, probably attempting to get a better grip via stilsons is worthwhile and failing that then it's cutting/reaming.

I guess some alu seatposts and steels must react differently as I have a 531 bike from 1982 that was seriously neglected by various members of my family before it was returned to me, only recently, and the pedals, stem and seatpost all came out without an issue, pedals being the tightest.

This bike I'm tinkering with is only 6 years old and the seat post is jammed solid.

Thanks
Gerry

[Mick F]

When I first got my 531c Mercian, I thought that 531 was a steel that was fairly resistant to rust. There is none on mine at all and it's 29 years old. Not stainless of course, just rust resistant. Less iron in the steel maybe?

Therefore, I reckon that what you say could well be true. Some alu seatposts stick and seize in some frames and not others.

[Brucey]

some frames are given a phosphate finish that retards rust. But the thing that really sets them off is salty water; even a short period of winter use with no mudguards will do it.

531 tubing rusts pretty well if you give it a chance....

cheers

[greyingbeard]

I just removed one by soaking with wd40 for a week. Held it with a stilson to rotate/wiggle then mole grips to wiggle it out. Not too much force, dont want to damage the frame.
A friend has a frame part filed with his favourite mixture of wd40, diesel and parrafin. Its been a week but Ive not heard if its come free yet.
Nothing corrosive in that lot.
Even a drip of wd on the frame top edge can penetrate. Plusgas is supposed to be much better but Ive never had any to try.
Good luck !

[Mick F]

some frames are given a phosphate finish that retards rust. But the thing that really sets them off is salty water; even a short period of winter use with no mudguards will do it.

531 tubing rusts pretty well if you give it a chance....

I bow to your knowledge, but I've used my frame through 28 winters so far. Not a scrap of rust at all.
What's no mudguards got to do with anything?
Mudguards keep YOU drier, not the bike.

I'm sure 531 will rust. I was being rather naive when I thought it was rustless, but I do believe that 531 and similar steels are better than "gaspipe" at resisting rust.

[Graham O]

I tried all methods with a stuck seatpost and eventually had to use caustic soda to dissolve the seatpost. It took about 36 hours, but it came out in the end.

If ammonia works, the best would be "half mile ammonia" or 880 strength.

Why half mile? How many yards in half a mile?

[deliquium]

I've got a psychedelic orange with black Jackson Pollockesque splatter painted 1992 GT Karakoram steel frame with a very stuck aluminium seatpost. I bought it like it (and cheap) purposely to see if I could learn something new.

Two separate attempts, each lasting 7 days, of filling the inverted frame with ammonia via a bottle cage boss failed.

The saddle clamp detached itself from the seat tube in a particularly heavy vice session afterwards.

Half a dozen attempts to hacksaw it out - amounting to several hours - have also failed

Another ammonia bash for yet another 10 days failed

I've left it for a year now, whilst it hangs on the living room wall - I just so love the "inferno" splatter paint job

I'll go back to the hacksaw when I get bored and HOPE yet again? It may be forlorn though?

The chap I bought it off offered to remove it for an additional £10 - I so wish I'd have taken him up

[531colin]

You can machine ream it out with a modified flat wood bit.....http://forum.ctc.org.uk/viewtopic.php?f=5&t=93589&hilit=speedbit&start=60

But I stick by what i said here about what to try first, and in what order....http://forum.ctc.org.uk/viewtopic.php?f=5&t=16716

[gerrymcm]

Success!
I tried stilsons and scaffolding tube but no joy for me, just severely dug into the soft metal. Not an issue as seatpost is scrap but I was worried about weakening the seatpost for further attempts.

Essentially I got a stronger bolt, in fact the the saddle clamp securing bolt, and a nut and tightened up quite tight against the seatpost via the hole I'd already drilled. Previous bolt must have been made of cheese.

I clamped the BB shell in my vice and then attached 4 ft sash clamp (what was that Archimedes said) onto the bolt/nut/seatpost. This is the bit that made the difference I think, I twisted it gradually but each time twist / pushing it a bit further until it CRACKED!!!! As I wasn't I expecting it 'go' with this sort of sound I thought that's the frame gone then! But no it was the seat post free.

I then flipped it over and secured the sash clamp /seatpost in the vice and another few squirts of WD40 down seat tube from BB shell I gave a good "back and forth" twisting and it came out Phew!!!!

I'm very pleased to have accomplished this and thanks all for your input I appreciate it.

Thanks all for your input.
Gerry