Now With The Benefit Of Hindsight....

[simonp]

Bad luck! It looks like it could be filed / filled and repaired though. I've recently built up a new bike and have a Dawes Audax (approx 2002) frame in 631 tubing which I was thinking of e-baying soon if you're interested in a replacement?
Simon

[saudidave]

You don't say if you got the rascal out in the end?

It's a bit irrelevant as he's knackered the frame now !

No he hasn't!. Strip the paint, "dress it up" (to quote Mick F) and repair the damaged metal, preferably with some sort of electric welding, so as not the weaken the metal with heat. I'm out of touch with metal jointing technology, but that's the way I'd go. I'm no metallurgist, nor structural engineer, but as a previous poster stated, with a seat post in there to spread the forces it should be perfectly OK

[CREPELLO]

I should mention that I did try good quality mole grips on the stub of seat post. If you ever use em, make sure that there is more seatpost showing than I had.With the post already sliced lengthways, then spread the post apart a little in order to get enough of the mole's jaws around a section of the post. I didn't leave enough post showing, so the jaws couldn't get enough purchase. That's why I resorted rather too quickly to the hammer and screwdriver.

You see? Another of my choicest benefits of hindsight

[cycleruk]

I wouldn't expect that small a hole to have any effect on the strength of the tube. Especially with it being at the end, next to the lug. The worst problem is if you have bent or made the tube oval.
If and when you get the post remains out, put a piece of round bar inside the tube and tap the "prong" back in.
Fill in the cracks with something suitable and then ream the inside.
Because of the lug, seatstays and top tube, at this point, this is probably one of the strongest parts on the frame.

[fausto copy]

Sorry to hear about this, but isn't that little sticker on the top tube hinting something?
Looks like a warning to me....."Stop".

If you do manage to get the blighter out and a new post inserted, then wouldn't the litile hole be strenghtened by the new post; especially if that one becomes seized too.

[531colin]

I have heard of (but not tried) vinegar,coke, and I think ammonia for dissolving the oxide(?) that sticks ali posts in steel frames. I have "reamed" one out using a home made reamer in a mains drill. Brutal but effective. The reamer was made from an old flat wood bit (speedbit?) ground to a sort of heart shape a shade smaller than 27mm. with a bit of a bevel to machine off the ali. It left a bit of ali stuck to the tube, but thin enough to peel away.
I suppose if we knew the chemical nature of the stuff that binds we could work out how to dissolve it.

[MikewsMITH2]

No he hasn't!. Strip the paint, "dress it up" (to quote Mick F) and repair the damaged metal, preferably with some sort of electric welding, so as not the weaken the metal with heat. I'm out of touch with metal jointing technology, but that's the way I'd go. I'm no metallurgist, nor structural engineer, but as a previous poster stated, with a seat post in there to spread the forces it should be perfectly OK

There is probably enough reserve strength to carry on using it. However you have created a tear in the metal at a stress point, which may ultimately cause failure. I wouldn't weld it, as 531 isn't designed for those kind of temperatures and you may actually make matters worse by making the metal more brittle.

You can get a good old lugged steel frame on the forum for under 50 quid. If it were me I'd put it all down to experience and recycle it.

[saudidave]

No he hasn't!. Strip the paint, "dress it up" (to quote Mick F) and repair the damaged metal, preferably with some sort of electric welding, so as not the weaken the metal with heat. I'm out of touch with metal jointing technology, but that's the way I'd go. I'm no metallurgist, nor structural engineer, but as a previous poster stated, with a seat post in there to spread the forces it should be perfectly OK

There is probably enough reserve strength to carry on using it. However you have created a tear in the metal at a stress point, which may ultimately cause failure. I wouldn't weld it, as 531 isn't designed for those kind of temperatures and you may actually make matters worse by making the metal more brittle.

You can get a good old lugged steel frame on the forum for under 50 quid. If it were me I'd put it all down to experience and recycle it.

Why don't people read before they post? MikewsMITH2 has quoted me and said that he didn't endorse welding it as 531 isn't designed for those sorts of temperatures and it may make matters worse. If he had read my post, and I quote verbatim
"Strip the paint, "dress it up" (to quote Mick F) and repair the damaged metal, preferably with some sort of electric welding, so as not the weaken the metal with heat"

Is it me? I give up!

[MikewsMITH2]

Why don't people read before they post? MikewsMITH2 has quoted me and said that he didn't endorse welding it as 531 isn't designed for those sorts of temperatures and it may make matters worse. If he had read my post, and I quote verbatim
"Strip the paint, "dress it up" (to quote Mick F) and repair the damaged metal, preferably with some sort of electric welding, so as not the weaken the metal with heat"

Yes I did read it properly. Electric welding will still heat the metal to its melting point. 531 is only designed to withstand brazing temperatures (<1200deg C) rather than welding temperatures (>3000 deg C). Once 531 is overheated it loses its flexibility and becomes weaker. Even too much heat with a brazing torch can cause premature failure. The advantage of MIG welding is that it will concentrate the heat in a relatively small area due to the cooling effect of the shielding gas. However welding it will still weaken the area rather than strengthen it and that's why I wouldn't advise it.

A skilled craftsman could braze it up.

[CREPELLO]

Sorry to hear about this, but isn't that little sticker on the top tube hinting something?
Looks like a warning to me....."Stop".

The little sticker actually declares the frame hand built. And now it declares that it was "hand destructed".

Actually, from reading all your posts, I reckon that the tear in the tube could be hammered back, then brazing used as a filler. I do think that as the tear is close to the lug that the repair will be well supported. Even if it does give way eventually, it won't be a catastrophic failure, unlike the bent forks (steerer) which I presented to the forum for examinaton last March, which would've been risky.

But how to get the remains out? I should go to an engineering workshop and ask whether, despite the mess of a fragmented seat post, they could ream it out. Because ammonia hasn't worked (that was the Sheldon Brown method). I suppose coke is cheap enough to immerse the cluster in, so maybe I'll give that a try.

[MikewsMITH2]

You might be interested in this detailed account of how to dissolve an alu seat post. I assume you aren't in a hurry?
http://www.classiclightweights.co.uk/seatpin-rest.html

[boblo]

I can confirm Sodium Chlorate and water will happily dissolve ally. How I laughed when I found my chainsaw in a puddle of spilled weedkiller and water after the tin had split. The ally crankcase dissolved leaving a somewhat knackered saw...

Beware though, you might get Special Branch knocking on the door if you start buying industrial quantities especially if you buy sugar at the same time....

If you don't fancy this, I'd either make a reamer as someone above did or pop it into an enginering company to sort it.

[Tonyf33]

Creppello, you'll be relieved to know I've a 60's Dawes sitting in the garage with strips of seatpost removed, got so hacked off( sorry about the pun) I just left it there to rot, seat tube not damaged but my will to wrestle with it died there and then, you have my sympathy.

[jeffjeffjeff]

Hello,

I've dissolved a inadvertantly non-adjustable aluminium seat post from a steel frame before using Caustic Soda.

The method I used was to strip out the bottom bracket to provide access to the seat tube, then secure the bike upside down. Angle the frame so the headtube is higher than the bottom bracket - otherwise you'll loose caustic out of the headtube before the seat tube is full.

Bung the end of the seat tube by stretching a piece of inner tube over the end, securing with cable ties then folding over the end and securing with more cable ties to make a watertight seal. Fill the tube via the bottom bracket shell using a length of plastic tube and a funnel. Best to dry run the filling with plain water before using the caustic.

Mix the caustic according to the instructions on the container. A stronger solution will speed up the process but don't make it too strong - I ended up with boiling caustic spurting out the bottom bracket shell at one point! Don't overfill the tube. The tube will get warm/hot once the reaction gets going. I changed the solution every couple of days, the drained solution is a murky greyish black. Keep changing the solution until it comes out clear. The whole process took about a week. Rinse the frame out very thoroughly, turn the right way up, grease new seatpost extremely well and install!

Needless to say the caustic is very nasty stuff, so treat it with respect - gloves, glasses and overalls required when handling.

Matt.

[ferrit worrier]

Why don't people read before they post? MikewsMITH2 has quoted me and said that he didn't endorse welding it as 531 isn't designed for those sorts of temperatures and it may make matters worse. If he had read my post, and I quote verbatim
"Strip the paint, "dress it up" (to quote Mick F) and repair the damaged metal, preferably with some sort of electric welding, so as not the weaken the metal with heat"

Yes I did read it properly. Electric welding will still heat the metal to its melting point. 531 is only designed to withstand brazing temperatures (<1200deg C) rather than welding temperatures (>3000 deg C). Once 531 is overheated it loses its flexibility and becomes weaker. Even too much heat with a brazing torch can cause premature failure. The advantage of MIG welding is that it will concentrate the heat in a relatively small area due to the cooling effect of the shielding gas. However welding it will still weaken the area rather than strengthen it and that's why I wouldn't advise it.

A skilled craftsman could braze it up.

I'd certainly go with the last line.

How much of the tube is left in? Have you tried knocking it "in" a little way this might just jar it free enough to start twisting it out? Good luck but don't dismiss the frame yet.

Malc