I have rough cut cypress lumber with blue marker numbers on them from the saw mill. How do I remove the marks

Question

I built a building using rough cut cypress, but there are numbers written on the boards in blue marker. I am assuming that the numbers were written on them at the sawmill to identify the select boards. How do I remove the marker without sanding the board down? I want to keep the roughness. I have tried a wire brush and sandpaper, but it starts to smooth the surface. Any suggestions?

Answer 1

Maybe try sanding it off. Dont use any oil. Maybe paint thiner would take it off.

Answer 2

Usually the markings are made by a wax pencil. Try methods for wax removal. Place a paper bag over it and iron so the wax melts and is transferred to the bag (or other material.) Or try methylated spirits.