I have built several realistic brick chimneys using white pine. Prepare chimney to proper scale dimensions, sand smooth, and spray with a ‘rattle can’ with flat terra cotta paint. Prepare your band saw with a “Stop Block” clamped behind the vertical blade to allow a depth of cut to 1/16" using the miter gauge to hold prepainted chimney square. Rotate the chimney with three more i/16th deep cuts to completely encircle the chimney. [If your miter gauge is square with the ‘work’ the last cut shoul line up with the first.] The cut through the painted white pine should look like a mortar joint! Continue moving the chiminey to the right or left the height of a brick and complete the four cuts for the full height of the chimney.
I have attached some photos.
Next clamp a straight edge for the verticle cuts a use a small “V” carving tool to carefully cut them 'with the grain. Avoid two grooves in a row, as it will create ‘stacked bond’ which is a non no. Good luck!! Larry NOMFNM