Previous owners had fastened down an inspection chamber lid on the patio,
but the screws will not budge.
Tried numerous applications of PlusGas, and it does disappear down the
sides of the screws, which later still refuse to move at all.

Apart from keeping on with the PlusGas, are there any other ways of
persuading the screws to turn?
(Last resort: drill them out...)

The cover and sample screw can be seen he

https://dl.dropboxusercontent.com/u/...tion-cover.JPG

https://dl.dropboxusercontent.com/u/...over-screw.JPG

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/\/\aurice
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