Coach bolt removal

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tim

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I need to remove a coach bolt. Boringly it is spinning when I try to undo it because the timber is old and so has given a little.

I can't damage the timber and I also the nut is recessed so I can't cut the bolt away and knock it back through.

If I try to clamp it then the other side of the clamp is in the way of the nut and any angled clamping is not sufficiently powerful. Tried a drop of superglue as well but again no joy. NB the bolt and nut are new and stainless steel so I know that its not rust etc as well.

Anyone got a smart tip to help me out of this please?

Cheers

Tim
 
Tim,

What size are dealing with? Could you stop the bolt turning with a socket while you drill a hole into the head, then knock a square tang into the hole to hold the bolt?
I assume you have tried WD40, but I find plus gas if you can still get it better as a release agent.
Could you heat the nut? Hot air gun or blow lamp, you are just looking for some movement to crack the metal to metal stiction.
 
Dave

Not sure I understand you (or you, me). The nut is not stuck except for the clamping force of the timber springing against the washer and then nut. The square head of the bolt (M10) has cut a round into the socket so that there is no antic rotation holding force against the timber. Consequently it is not possible to hold the bolt still to undo the nut.


Cheers

Tim
 
Tim,

I've had success in situations like this by driving small wedges down the sides of the bolt haed, but this may damage the wood slightly. I would try epoxy resin to glue a nut onto the top of the botl head that will give you an extension to use with a spanner to grip it.
 
Tim,

Does the bolt have to be kept intact? If not, d'you have a Dremel or similar and a cut-off disc? With a little care you should be able to cut yourself a little screwdriver slot, just enough to give you a purchase on the bolt head. If the bolt head has to remain unmarked, it's possible, if you're really cunning, to cut a similar slot in the thread end on the bolt (and partially in the nut if the bolt end is flush, but that's just too bad) and use a screwdriver narrower than the bolt to hold it while you use a spanner on the nut. It doesn't always work, but an M10 bolt at least gives you the chance of using not too tiny a screwdriver.

Cheers, Alf
 
Tim,
Can you knock a suitably sized bit of copper pipe or Aluminium tubing over the nut to act as a socket? I have had success with this once or twice.
 
Thanks guys - all good suggestions although the epoxy option has been tried and fails and I don't have anything small enough to cut a slot in the head.

Chris - I have a socket around the nut - thats not a problem - its holding the head still thats the issue.

Cheers

Tim
 
Could you clamp the head down tightly, to stop is spinning? Maybe using some rough sandpaper to give it some more bite (against a G clamp or similar)? Or can you lift the head enough to slip some sandpaper under it to try and hold it rigid? E.g. add some friction?

How about putting the socket in an electric drill and in reverse, it maye just spin it off due to the friction on the main bolt shaft?

Adam
 
can't you drill a small hole from the centre of the head, that is at an angle and finishes in the wood. Then you can insert a bit to stop the bolt spinning whilst you undo the nut.

Andy
 
Thanks for all the advice guys.

I tried the 'increased grip' options earlier with no joy and I also have had no luck on drilling either end. Its stainless steel and I don't seem to be able to get any bit to bite into it effectively.

Can't get under the head or nut with wedges without damaging the surrounding timber - so I'm still a bit stumped. I needed to remove it to cut the thread slightly shorter and to replace the nut with a nyloc one to match the others (on an oak outdoor table) but I think given its position I can get away with what I done by grinding the set off a hacksaw blade and cutting flush (very dull job!!) and then peening it to prevent it ever undoing!!

Cheers

Tim
 
Hi Tim,

If it is possible to access both ends of the bolt with a clamp, an old fashioned car engine valve-spring remover might be the answer. These have a 'fork' on one end of the clamp which would fit around the nut end rather than on it, whilst the other end would sit tight on the bolt head holding it firmly in whilst the nut is undone. With a bit of luck this would probably work. I might have an old valve-spring remover somewhere in the garage.

Cheers,

Trev.
 
Hi Tim,

How protable is this item? I quick visit to the local garage might be in order, use a nut splitter to break the nut completly then you ushould be home free.

HTH
Les
 
If you have a hacksaw, use that to cut a slot in the top, doesn't need to be too deep. You should be able to use a large screwdriver or if the slot is too big, use any piece of metal that might be kicking about. I've used an angle bracket in the past.
 
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