I've got an immersion heater mechanical flange similar to that
supplied by Toolstation.

http://www.toolstation.com/shop/Heating/Central+Heating/Mechanical+Flange+2+14/d230/sd2708/p38614?

The flange is slightly loose, the cork seal leaking, and I have next
to no access to the rear, certainly not enough to get a spanner in. I
am sure the flange was fitted before the tank was welded together and
while there is a hex on the outer diameter of the inside of the
fitting it is only just feelable with my fingers, the bore of the
internal part is smooth and there appears to be no way to hold it in
place while I apply a loosening action to the external hex.

Any bright ideas on how to slacken it off so I can fit a new washer?

Before anyone suggests it I have considered using an angle grinder but
the flange is in a stainless steel tank and even though it is vented
and operating at atmospheric pressure I am really reluctant to start
hacking access holes in it.

P.S. Do they make 'internal' stillsons ?


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