Bill Haines wrote:
I have this tank in the roof space. Not sure if it's plastic or
fibre-glass, because it's texture in parts is very uneven,
not what I
imagine a moulded PVC tank would usually be like.

If the tank is Black it is probabably a rotationally moulded
Polyethelene (or Polypropelene)Tank. If it is GRP it will probably be
grey and very hard.


There's an obsolete 15mm outlet that used to supply a shower unit. For
some reason, maybe to maximise the pressure, the hole for this outlet
is very close to the bottom edge of the tank, leaving little room for
any flanged fittings that might be used to seal the hole. The current
union with the tank is a male threaded fitting that's just screwed
into the wall of the tank after being wrapped in PTFE tape.

This leads me to believe that it is a Polyeth or Polyprop tank as you
couldnt do this with GRP.

I could
try renewing this with fresh tape but I'd prefer to make a more solid
repair. Can anyone suggest an effective method?
Thanks,
--
Bill Haines

I should leave well alone or replace the tank. It is a bodge that is
holding. As an ex tech consultant to a tank manufacturer I have seen
hundreds of such bodges. The mind boggles at some of the corners that
are cut when fitting such tanks.