On 6 Apr 2018 15:45:19 GMT
David wrote:

Just tried to sharpen a builder's pencil and the two wood halves came
apart.

Pencil sharpener for normal pencils is blunt.

I am now considering a propelling pencil with a thick lead for use in
marking up work.

Anyone else doing this?

If so, which lead thickness?

I have a clutch pencil (rather than "propelling") with approx 2mm lead
that withstands vigorous use quite well (and has a sharpener in the
other end). Not sure how well it would work on rough sawn timber, but
for that I might strike a line with a knife to make it easier for the
pencil.