I don't actually have to do it the way I'm doing it; my original idea
was to use some plywood on both sides of the old post. That way I
could avoid drilling the old post. But this way is easier: The post
is a little smaller than a 4x4. On the end of that I'm mounting a
thin board, then a 4x4. (Need the board because the post has a wooden
"cap" that prevents the 4x4 from being flush. Need the 4x4 to be
taller than the cap to mount the gate hardware.)
Didn't know about the difficulty of drilling 8" straight, but
fortunately won't have to deal with it. I can drill the board, the
4x4, and the post one at a time.
This would be even easier. Counter boar the 4X4 about 3 inches deep, and
then drill a clearance hole a wee bit larger than the major diameter of the
wood screw. Do this in two or three places.
Next using the holes drilled in the 4X4 as a guide, drill corresponding
clearance holes in the thin board.
Now you can use the thin board as a guide to transfer the location of the
three holes to the post but these holes will be pilot holes for the wood
screws, so the diameter of the holes would be slightly smaller than the
minor diameter of the wood screw.
Now you will have a sufficient anchor to mount the baby gate and it will be
cheaper than the through bolt method and plenty secure.
Or "Plan B" would be to secure the 4X4 and the thin board to the post with
large stainless steel hose clamps, (Also you could add a chunk of wood to
the back side of the posts to prevent denting the wood.)and then you would
have no holes to repair after you take down the baby gate.
About the time I had mastered getting the toothpaste back in the tube, then
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