I tried making coating rods out of 3/8" and 1/2" diameter acrylic
rod (purchased from a plastic supply store similar to TAP Plastics in
the Western US) but was not pleased with how they worked. I had a
hard time getting them to make even contact with the paper and the
sensitizer seemed to "stick" to the acrylic much moreso than with
glass. This resulted in a little wasted sensitizer. The main
problem was the uneven coating. I get very good results with glass
rods made from tubing rather than solid stock.
Kerik