Advice on drilling long perpendicular holes
I am building a shelving unit and trying to wire some LEDs. I have to drill holes about 8” down into the shelves so that I can then route out some recesses for the lights and run the wiring through the holes. It’s 3/4” material, and the hole needs to be 1/2”, so there’s not a lot of wiggle room. It needs to be perfectly straight. I tested it out a couple times with a few different methods, messed up a few test boards, and landed on what I thought was a good solution, which was a long 1/2” drill bit and a doweling jig. I drilled the first one and all seemed great. Then, for hole number two, I got this. A few questions:
1: Is there a better method than this one? I have to drill 8 more of these holes and I want don’t want to mess up again. Some of the holes I have to drill are in solid walnut that I REALLY don’t want to mess up.
2: Is there a fix for this other than just a new sheet of plywood? Can I patch the veneer? Anyone have experience with that? It’s the underside of a shelf, so it’s not super visible, and I’d like to avoid buying another sheet of walnut plywood if I can.