John Lucas
I was making ornaments one day and decided to see if I could make one that looked like bricks and concrete but would of course be hollow and very light. It worked out so well I decided to build a lamp using the same technique.
I cut grooves in the lamp. I used the toe of the skew for the horizontal lines and ground a brocken router bit to shape to make the short vertical lines. I used a table top tool rest for the router and an index head to keep them lined up.
Then I dyed the lamp red and sealed it with lacquer. Then I rubbed dry wall mud into the grooves. I wiped off most of it with a damp cloth and then carefully sanded with fine paper to get rid of the rest after it dried. Then I applied my usual lacquer finish.
The concrete was done by spraying Krylon Stone Flek onto the wood. This gave it texture. Then I sprayed it with Gray primer. Then I used white spray paint and held the can about 2 feet away. I just sort of squirted at the gray until it had lighter more concrete look.