Need help removing bolt and nuts from a mailbox

Question

I'm not really handy, and so this is the first time doing something like this. I have a 15+ year old mailbox which is fastened to a metal post by four quite rusted bolts and nuts on the side. The bolts are of the slot types, so I thought it would be a simple as unscrewing them with a screwdriver. Unfortunately, the nut (which is a bit thinner/smaller than a standard nut) also turns with the bolt.

I've tried to do the things suggested in this question (using a wrench/pliers), but haven't had luck so far; holding down the nut while turning the bolt head just makes the screwdriver slip out of the slot.

I've applied some lubricant, but no dice either.

I don't have access to any power tools like a drill either, and I wouldn't be sure what to look for in a store. Any other suggestions?

Answer 1

Spray it with a bit of penetrating oil, then sit back and wait for a bit (a beer or two ought to do it). Then try loosening the bolt again. Repeat until the bolts are out, or you're too drunk to care.

Answer 2

If your screwdriver is slipping out, it may be to small. Or possibly you need another set of hands to help with this project.

Very rusted bolts can be extremely difficult to remove. If penetrating oil, as suggested by Tester101, and the proper tools (big screwdriver, wrench, vice grip pliers, etc.) don't work then you may have to cut the bolts off with a hacksaw, or dremel and then replace them when you reinstall.

Use galvanized or stainless steel fasteners when you reinstall to reduce the future corrosion problems.

Answer 3

If you're driving a flat screw against a rusty thread, you really need the screwdriver to be perfect in the screw head, exactly the right size. That requires careful choice of screwdriver and maybe using a wirebrush or something to knock the rust off the slot.

If you have a tap and die set, you can also try running a die up the rusty threads to clean them up. Start it properly, then once you've run it up, flip it over and run it again to clean up the threads you couldn't reach. That's still not perfect but it'll save you time later once you get the nut turning.

As far as penetrating oil, use the good stuff. Kroil is excellent, Liquid Wrench is at least available everywhere. WD-40 is exactly what it says on the tin (Water Displacer 40) and is not a penetrating oil at all.

The last resort is to get a Dremel moto-tool and saw off the bolt, nut or head. I use those fragile little discs, very very carefully with close attention to the stresses on the spinning disc. Sort of like that guy who uses a sheet of paper in his table saw. Or you could acetylene, use a nut splitter, whatever floats your boat.

If you don't want it to happen again, use stainless steel or brass. Or use hex-head, socket-head or Torx head fasteners rather than slotted or Philips.