Advice on removing bolt from enamelled flue

a_ominous

I need to clean the chimney but I have been unable to remove the bottom bolt, with a Philips head. It's starting to shear, so I've been hesitating tackling this again. I suspect there is tar around the bottom bolt; the top one has been removed and there was some leakages around the bottom of the panel.

This is a new flue pipe, fitted about 18 months ago after we had to get chimney rebuilt from the ground up. Old access panel had bolts with hex heads I could remove with a spanner.
The chimney needs a good clean; it smokes every time we light it now.

Any advice on how to get panel open without damaging the enamel?
TIA

The Red Ace

as a diy job I would advise you to have a new no2 pozi drive tipped screwdriver and tap the screwdriver with a hammer as you try to back it off

Robbie.G

a_ominous wrote: »

I need to clean the chimney but I have been unable to remove the bottom bolt, with a Philips head. It's starting to shear, so I've been hesitating tackling this again. I suspect there is tar around the bottom bolt; the top one has been removed and there was some leakages around the bottom of the panel.

This is a new flue pipe, fitted about 18 months ago after we had to get chimney rebuilt from the ground up. Old access panel had bolts with hex heads I could remove with a spanner.
The chimney needs a good clean; it smokes every time we light it now.

Any advice on how to get panel open without damaging the enamel?
TIA

You need to make sure the screwdriver you have is an exact fit then with the screwdriver in place struck the top of the screwdriver a few time then try to unscrew it

Kevin McCloud

They are a pozi 3 screw, using a smaller screw driver will only make shit of the screw.

phog

If that flue pipe is cast iron be careful about tapping the screw as it could crack the pipe.

It probably isn't cast iron but just be careful.

Give it a shot of WD40, let it soak in the try a correctly sized screwdriver, apply even pressure on all points of the screw and turn. Easier said than done but it's also easy to round the inside of the screwhead.

fergal.b

Try using a screw gun and set the ratchet on low working up, the slipping action of the ratchet works like an air gun and should work it loose.




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CJhaughey

Heat the screw up with a small blowtorch and use a small manual impact driver gently to unscrew it.
I would also get a small dab of valve grinding paste and put that on the head of the screwdriver for extra torque.
Then replace the screws with hexhead screws which will take more torque or a small bolt.

If the worst happens and the head strips out so you can't unscrew it, drill the head off with a steel drill and then use a set of vice grips to remove the stub of the bolt.
Heat will make the job a lot easier.

a_ominous

WD40 and correct sized screwdriver seem to have worked. Left the WD40 on it for the week and was able to open the hatch and clear the chimney today.
Thanks