I have a vinyl fence post that was filled with cement. The vinyl fence panel brackets were screwed in before the cement was added so this wasn’t an issue, But now a few brackets have broken off and I am having trouble replacing them. Every vinyl screw breaks when I try to go into the cement even when I pre-drill a hole. And the cement screws don’t seem to be holding. Am I just not using the right screw, or is there a better way to attach plastic to cement?
You can try a self-tapping concrete screw, as long as the concrete is not brittle. You need to pre-drill a pilot hole but after that nothing more than screwing the screw in. The only problem is the screw size is probably a little bigger than you need. I think 3/16 x 1-1/4" is the smallest made, but other manufacturers might make smaller.
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