Painter to damage high gear on cart, not second (8,5)

'cart not second' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'painter to damage high gear' is the wordplay.
I cannot really see how this works, but
'to' is found in the answer.
'damage' could be 'mar' (to mar is to spoil or damage) and 'mar' is located in the answer.
an anagram of 'gear' is 'gare' which is present in the answer.
This may be the basis of the clue (or it may be nonsense).

'on' acts as a link.

Can you help me to learn more?