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 ? :)