Seatpost stuck - where would I get Caustic soda from?

hose pipe through the BB ?

nope i meant full dry out the seatube?
wd40?

@damo, tried that

anyone else, successfully used it?

Yes.

It took several goes, over a few days, plugging all the frame's holes and leaving it to bubble inside the tube.

good man, how did you clean out the tube afterwards?
my frame is tig welded, so there is no holes to the b/b or stays.

EDIT More cold water. Then hairdryer? Srsly.

i wouldnt recommend it, i did it twice a day for 2 weeks and nothing much happened except it stripped the paint off the frame down to bare metal. seatpost was still in there

http://yfrog.com/0wdsc01101aqj

good man, how did you clean out the tube afterwards?
my frame is tig welded, so there is no holes to the b/b or stays.

flushed it out with detergent and warm water, then gt85 then wd40 then ub40

cheers, Rob

flushed it out with detergent and warm water, then gt85 then wd40 then ub40

*

*does one exist? It ought to.

Let us know if the caustic soda thing works, I have got a post stuck in my racer.

how you gonna get it inside your frame though to the stuck part? do you have to take your bb out? will the caustic soda fuck up your paint?

Yes, eventually; through the BB shell; exactly; yes, definitely.

I used water and vinegar to clean my frame out.

Did this to an old frame, it took over a week, ruined a decent paint job and gave me a couple of alkalai burns but got the job done eventually.

took me 24 hours, all good.

How did you get it out in the end?

i wouldnt recommend it, i did it twice a day for 2 weeks and nothing much happened except it stripped the paint off the frame down to bare metal. seatpost was still in there

http://yfrog.com/0wdsc01101aqj

Lot of people seem to find that the CS destroys the corrosion before the post, and you can then yank it out - but mine dissolved from the inside out, and I had to wait until the whole post had changed into a foul-smelling metallic paste before I could use the frame again.

the answer to anything stuck to anything is heat. just pour a load of oxy-propane heat on it and pull. it will move. of course the paint will be utterly buggered, but the surfaces of the metal will not.

I tried using caustic soda, having previously tried GT85, Plusgas and other lubricating agents [snarf!]. After several weeks of using a super-saturated solution (i.e. so strong that it wasn't disolving any more) I gave up and sent my frame to Mercian, who nuked the seatpost out.

I think once I worked out how much it had cost for the various lubricants, two packets of caustic soda, hacksaw blades for the 'drop a blade down the open seatpost' trick, etc... getting it done professionally was cheaper (albeit it wounding to my DIY ego).

it cost me £1.69

^ but you got it fckin everwhere

cockoff!!

:)

the answer to anything stuck to anything is heat. just pour a load of oxy-propane heat on it and pull. it will move. of course the paint will be utterly buggered, but the surfaces of the metal will not.

Well, except in the unlikely event that it's aluminium inside steel, because aluminium expands more than steel, so heat would only make the problem worse. I can't think of anywhere that might happen. Maybe some kind of aluminium pole, or post, inside some kind of steel tube...? No, I agree, seems pretty unlikely.

We have a paint-stripping business and use potash flake and caustic soda all the time, should do the trick but it can do nasty business with aluminium - it doesn't look pretty anymore after it's been in contact with caustic. We did some galvanised trailer parts a while back - took the galvanic layer clean off.

After several weeks of using a super-saturated solution (i.e. so strong that it wasn't disolving any more) I gave up and sent my frame to Mercian, who nuked the seatpost out.

Yeah, I made this mistake with one batch. If you make it too strong it won't work. Why did you give up? Just use a weaker solution no?

You say nuked. How did they actually get it out?

i've never had any fluid, anomina caustic etc. do anything to get a totally jammed post out.

grind top off and pad saw down inside - it doesn't take that long