Keen on fixing tungsten objects on the fence (2,3,5)
I believe the answer is:
in two minds
'the fence' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'keen on fixing tungsten objects' is the wordplay.
'keen on' becomes 'into' (if you're 'into' something you're keen on it).
'fixing' means one lot of letters goes inside another (inserted letters are fixed inside others).
'tungsten' becomes 'W' (W is the chemical symbol for tungsten).
'objects' becomes 'minds' (to mind something is to object to it happening).
'into' enclosing 'w' is 'intwo'.
'intwo'+'minds'='IN TWO MINDS'
'on' is the link.
Can you help me to learn more?
(Other definitions for in two minds that I've seen before include "like Dr Jekyll at times?" , "where similar ideas may be foolish or clever" , "Torn" , "Wavering, undecided" , "The outcome is uncertain" .)