Stuck seat post - Aluminium in steel - electrolytic reaction

[Mattsheavyiro...]

Hello all,

I'm new here so hope I'm following the rules & protocol ok.

I wonder if anyone can help... I have a seriously stuck seat post which is cracked at the top, meaning the saddle fitting is unreliable (& I don't dare imagine the consequences when it finally gives !).

The post is aluminium & the frame is steel (Ritchey Logic with an anodysed titanium finish) and I'm told by a friend (who is very experienced in metal joints & welds etc - but how to make them, rather than break them) that it's an electrolytic, or Galvanic, reaction which has bonded the two together (the post has been in there a long, long, long time!). He suggested that 'oil of wintergreen' (Methyl salicylate, apparently) could possibly dissolve the bond, but I've no idea where to get such a stuff, or at a fair price.

I've tried the generous application of violence, of course (including myself & a sturdy friend with a stillson wrench around the post - so I do mean violence!) and it ain't going nowhere! Given that the post is cracked (& I have a new one waiting) as far as I'm concerned it's waste, I'm willing to drill, saw and/or attack it with chemical warfare, and of course to step the violence level up if needs be - but I really don't want to damage the frame... any ideas?

(& by the way, ditching the entire bike & buying something that isn't steel isn't an option financially, plus I love my old horse, she & I have been across continents together, I'm just not comfortable about sending the old nag to the knacker's yard, not yet ...!)

Thanks all. M.

[ThatDippyTwat]

What size Engine does it have?

[MattEMulsion]

Could you post a picture of the offending item to give us more of a clue?
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Yamaha YZF-R6

[bamt]

If you can't remove it mechanically, then caustic soda is the way forward ; seal up the post, turn the frame upside down, then pour it into the frame from the bottom bracket. It dissolves the aluminium but doesn't touch the steel. Never needed to do it myself, but I've seen it done - it takes days rather then minutes.

Nasty stuff though, and it can affect your paint. If you google seatpost and caustic soda you'll find loads of hits and videos.

BTW, the pushbike part of this forum is here.

[hellkat]

*deleted due to incomprehensible and mistakenly irrelevant waffle*


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Not nearly as interesting in real life.

[Pjay]

I have the toppest of top tips.

Coca Cola.

Pour it down there, find a way of making sure it holds in there and overnight it will eat that oxidation buildup that is causing it to stick and it wont damage either surface and pull right out.

Sauce: Done it about 10 times in my life and never once failed.

[stevew]

Also worth holding the post in a big heavy, well fixed down, vice. then trying to wiggle the frame around.
Much better leverage that way.
Even better than stilsons
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Maxsym 400i 2013, Sterling 125 2017, Honda Wave110i 2014,
Orpington
The opposite of bravery is not cowardice, but conformity. Robert Anthony

[Dave....]

^^^^^
As said above.
If that fails then cut it off at near top and use a hacksaw blade without hacksaw itself down inside seatpost and start sawing but careful to keep it flat and not cut into frame.
I had to do this to someones bike that had carbon fibre seatpost stuck in which was hard on blades to cut but got there, eventually.

[Mattsheavyiro...]

Thank you all for your responses, I'll see how I get on - & apologies for posting in the wrong forum