ok drill all of your holes through one side of the pvc pipe...for example
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now have a friend or somebody hold the pvc onto the piece of wood with the holes facing up....
(holes on top)
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=============================== --wood lol
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Now drill through your preexisting holes and put a screw through the bottom of the pvc and the into the wood. Trust me the holes on top will not effect your skiing at all, This way gives you secure pvc and it glides like a champ and has been a good rail for 2 years now.