Exhaust manifold bolt

[Turb()]

Not sure if this is the place to put this but here goes.

My exhaust is blowing where the manifold meets the down pipe. All it needs is a new gasket and tightening up... however... 2 of the 3 nuts have sucessfully come undone while the 3rd one has rounded.
As many of you probably know the nuts are downwards facing so rather fiddly if, like me, you are attempting to fix this on the driveway.
I need to get this nut off now either way, but my question is what is the best way to go about it?

I know you can get those nut extractors that eat into the nut to remove it, but halfords only sell them in sets up to 12mm when my nut is 14mm
I also considered putting some chemical metal inside a 14mm socket and holding it in place until it sets - but my worry is getting the chemical metal where I dont want it and having a socket stuck over the nut I cannot remove
I dont think a nut splitter would fit given the lack of space I have to work with.
I have thought about using a hacksaw to cut the bolt, but the bolt seems to be part of the manifold so then I would have to either hope I can drill the rest of it out or hope that I can get a decent seal with only 2 bolts?

Oh yea I also tried whacking a 13mm socket on, but there isnt a lot of space to try and do this from underneath on the driveway so this was not successful

Any suggestions? Its really doing my head in lol

[Henry]

If it was mine, drop the manifold of (12mm bolts) unbolt the front section of the exhaust and lower it down and out.

Then you can get grips, cracker ect onto it.

Be careful when ordering the "gasket". What you describe is actually a wire exhaust cone.

[Turb()]

Mines not like that, its a 4-2-1 manifold so has a flat mating surface with 2 holes in it

But what you said seems a good idea trying to drop the exhaust down from the front

[jblack1210]

soak it in plus gas for an hour or two, its the best stuff.

then try and whak on a slightly smaller socket or get a set of 6 inch stillsons on it

(probably wishfull thinking getting stillsons on though with the space you will have available)

id suggest taking henrys route though, it will be the most stress free method!

you just end up pulling your hair out when your fuckin about in trying to do things the ''easy'' way!

[Henry]

soak it in plus gas for an hour or two, its the best stuff.

then try and whak on a slightly smaller socket or get a set of 6 inch stillsons on it

(probably wishfull thinking getting stillsons on though with the space you will have available)

id suggest taking henrys route though, it will be the most stress free method!

you just end up pulling your hair out when your f**k about in trying to do things the ''easy'' way!

Yes sometimes it does pay to do it the slightly longer way.

I had a vit, wanted the inlet off it, but rounded a bolt. i spent half a day wanking about with it, in the end it was easier to take the engine out to get a good bite on the nut!

Sadly the engine died last year