Sunn Exact Ti stuck seatpost

[andyparle]

Re:

I should have probably left it over night as you say, 2 hours wasnt long enough. Im not sure why chopping the seatpost and pouring it in from the bottom bracket would have been any better other than completley losing the seatpost? It is the shim that is causing the problem and there is a slight gap around it where it has been prised so the caustic soda cold penetrate the way I had it set up. The crank bolt were seized and rounded anyway plus the bottom bracket was seized so it had to be drilled out in the end.
Such a shame that someone neglected it to get to this state (and then butchered it to try and fix the problem).
Ive got hope in the frame builder though so im not giving up yet, plus i have all the parts ready to rebuild her.

 

[ted andkilde]

Re:

Worst case, you should be able to have a machinist strap it into a mill and bore/ream (or whatever technique they deem fit) the remnants of the old post and shim out.

Cheers, Ted

 

[andyparle]

This has been dicussed as a (very) last option with the frame builder, but i think its drawing close to that stage! Eeek...

 

[andyparle]

Update! The frame builder has slowly been working away at it. Now the frame has killed two quality reaming tools and damaged the machine as well, this is some tough as f*ck titanium!!
There is a possibility to use the stuck part remaining inside the seat tube as a shim and he thinks we could fit a 25.4 isn seatpost in there for the amount of material that has been taken off the inside of the old post.
This I can certainley live with if it works

 

[andyparle]

So. Finally, ive gotten the frame back. both the post and top of seat tube had been part ovalised (in opposite directions) because of the force from the last owner trying to prize open the seat tube with a screwdirver :facepalm:
So, they have chopped below the seat clamp and created a new slit , which although is wonky works (it needed to be because of how the material around the hole had warped. They have filled in with silver solder a couple of bits were the aluminium shim had melted away. It doesnt look great and I might ad a little metal filler/silver solder just for vanity around the top. I think a double bolt clamp as well so I dont have to exert too much pressure on the top.
Ive cleaned off the sticker residue and I am considering giving it a brushed look.

Just hope it fits me once I have built it.....

 

[coomber]

Re:

That looks ok.

Once the clamp is on and the bike built up doubt you'll give it a seconds thought. Still a shame the butchery pre your ownership but can't change that now.