Seat post/saddle bolt stuck?

[aj82]

I am trying to replace an aging and unpleasant saddle, simple job I know, but it's also an old bike that has been in the wars and on taking the seat post out found that the bolt underneath the saddle that holds it in place was stuck fast.

There's patchy rust on it and despite 'heroic' efforts with an allen key it's not going anywhere in a hurry.

So my question is, are there any tricks I can usefully try to get it moving or am I going to have to suck up a few more quid and get an LBS to install it for me?

 

[HLaB]

Try a few squirts of WD40 or something leave it for a while and try again.

 

[Globalti]

You can shock free a stuck thread by giving the head of the bolt a hefty wallop with a hammer, but this needs the material into which the bolt is fitted to be very solidly supported in order that the threads take all the shock.

Impact screwdrivers work partly on this method and by applying a twisting shock at the same time.

 

[twentysix by twentyfive]

Try warming up the outer parts so they expand away from the bolt. A cookery blow torch is quite useful for this.