The message
from "Grumps" contains these words:

I am trying to dismantle a child's climbing frame. It is contructed from
metal tubes. It has six legs which are formed by inserting short tubes into
each other. It has been standing for 7 years, and I cannot pull these
pieces
apart (well, I have managed two). Any advice?

Graphited penetrating and easing oil. WD40 claims it's good, but it's
not a patch on the proper stuff.

Dribble it round the joint (invert the frame if needed so the oil can
trickle down into the crevices) and leave it a day.

Warming it will help, too. With concentric rings, the outer one will
always expand more than the inner as they're heated.

--
Skipweasel
Pay no attention to that man behind the curtain.