Question and pic on abpw

1. Stick a 1 inch sanding disk on the end of a dowel. Maybe need to cut a 1 inch plywood disk and glue it to the dowel, or use an automotive valve to hold the sandpaper disk.
2. Cut all the holes with an upcut router bit and a template
3. Cut all the holes with a pattern bit.
4. Drill all holes with a Forstner bit so you don't have deep lead spur holes in the bottom.
5. Go with either 2, 3 or 4, followed by 1.
6. Slice off the bottom (like a bandsaw box), cut all the holes, then glue the bottom back on.

#6 wins!

Paul, thank you for adding the width of the slot, the depth of the slot, and the length of the slot you need to sand. Thanks for adding the type of wood you're using and what you've tried so far.

It helps to know these things in order to know what not to offer as well as what to offer.

People like you call into body shops and ask questions like "How much will it cost to repair my fender?"

-- ...in order that a man may be happy, it is necessary that he should not only be capable of his work, but a good judge of his work. -- John Ruskin

Do you have a router? You could use a plunge pattern bit to clean up the bottoms of those holes to the point where they could be hand sanded. Sanding down far enough in oak (looks like, to me) to remove those to tip marks is going to be a major PITA with whatever technique you try.

I have had phone calls like that... " What do you charge for **insert one or some of the following**>> a kitchen, a countertop, a bathroom renovation, to refinish my diningroom furnitue, build me an entertainment centre