A quick and easy way to make top bars with an angled comb guide is to use corner molding. Here is how I do it. First I make 17 inch top bars with no kerf (not needed) out of ¾ inch stock. Then I cut 12 inch pieces of hardwood corner (cove) molding that I get at Lowe’s. Center the molding then glue and screw or glue and nail it to the top bar. I use an electric brad nailer and waterproof carpenter’s glue on mine. The bees are building on them nicely and I’m pleased with the results. I waxed the edge of the molding but on the advice of Michael Bush I’m not waxing them in the future. Another thing I like about this method is that you can buy just 1-8 foot piece of molding at a time if you like.