Unscrewing the impossible

Have you ever had to remove rusted old screws from wood without destroying the piece? How about eighty of them? Forget impact drivers or ‘screw extractors,’ this calls for some creativity!

Rusted, buried screw heads in porch deck
Yep, there’s 4 screw heads in this picture. Now picture 76 more

Here’s the setup: a 30-year-old porch where you had to take off five boards, but the idiot* who built the porch used Philips-head deck screws instead of square drive, and the screws have gotten all crudded up with wood preservative and rusted in place. You know you’ll just strip out the heads trying.

Carpenter's brace with Philips' head screw driver bit

A carpenter’s brace is the right tool; put your screw bit in as if it were a drill bit. It lets you apply massive downward pressure and torque with super-fine control, and it has a ratchet for tight spots.

Pointy tool for cleaning out screw heads

Also, clean out the screw heads with a Very Pointy Thing. A dental pick will work, though I made a tool by sharpening a deck screw on the grinder.

Modified Philips screw head optimized for screw removal

Finally, modify a #2 Philips-head driver by grinding the edges to a sharp bevel that is optimized for removal (and would be useless for installation), and grind off a bit of the tip so any remaining crud has someplace to go.

It’s difficult to express what a dramatic difference this makes. Screws that are otherwise impossible, become easy.

Detail of modified Philips head screw bit. Notice edge angle has been tilted to optimize for screw removal. No way you could drive a screw in with this bit.
  • * yeah, that was me
  • This technique for removing old screws ONLY works if the wood is bone-dry
  • UPDATE the groundhog did a lot more damage than I thought, so the job got too big to do it this way.

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Older technology guy with photography and history background