Prentice Hand

I came across the phrase in Driftwood and Tangle by Margaret Leigh.
Chapter 10 - At the Peats - is set in 1940. It is, in part, a reflection on WWII.
Leigh also describes her kackhanded cutting of the peat leaving the bank gashed and uneven...

as if it were a huge chunk of butter at which a boy had been hacking with a blunt penknife.

For those of us that have not put 10,000 hours in the meter ours will always be prentice hands.