Loosening Stubborn Wood Screws With Heat


Introduction: Loosening Stubborn Wood Screws With Heat

An old boatbuilder's trick for loosening wood screws.

Step 1: Supplies!

You will need:

A stuck wood screw - in this case a smallish, thinnish, bronze slotted flathead screw.
A length of steel rod matching the size of the screw head - I used a 20d nail.
A propane torch.
Vise-grips - 'cause your gonna make that nail HOT.
A screwdriver that fits the screw well.

Step 2: Make Some Hot Metal.

Cut the end of your steel rod square if it isn't already. Avoid using galvanized steel, burning zinc makes nasty fumes.

Heat the end of the rod cherry red.

Step 3: Heat the Screw.

Hold the heated end of the rod against the screw head for thirty seconds or so. Repeat this process two or three more times.

This softens the wood fibers around the screw and also breaks any glue bond.

Step 4: Remove Screw.

Carefully remove screw. There is no need remove it while still hot. It is remarkable how well this works.



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    This worked like an absolute charm!!

    Had been trying to get a screw out for 3 hours no luck, did this, 2 minutes in the fire, 1 minute late screw was out! Nice one!!

    Ref: Using a soldering iron to get a bugger-stuck wood screw out. Thanks, it worked for me! Although you said you used it on plastic situations: I got a leg screw (2-1/2" flat head) out of a chair...odd angle to boot - It wasn't easy and it took 3-4 tries and I had already lost about 1/2 of the slot from my first attempts without heat tries. Now two more....ah...manana, it's time for cherry pie.
    I think if you leave that soldering head on the head until you start to smell the wood/glue heat-up may be the trick. First two times were probably too short -
    Last time I held it there for about three mins. Also likely that there was a
    cumulative effect.

    @chuckr44: This method should work for torx screws too.

    Would this work for plastic?

    yeah, this not only loosens the wood fiber, and breaks glue bonds, but it also expands the screw, making it more difficult to extract. this DOES work, but my favorite method, is to take a can of air, flip it upside down, and spray the screw with the freezing cold liquid ((difluorothene I think) be sure none of the liquid touches water, it will make hydrofluoric acid, and will eat the flesh off your bones.) this shrinks the screw a bit, allowing it to be loosened easily. I'm going to try a combonation of these methods, to see if they work well together. (first heat, then freeze.)

    2 replies

    Well, there is perhaps some infinitessimal expanding of the screw, but I can assure you it Does Not make it harder to remove.

    I think people are getting the wrong idea about how much heat is being applied to the screw. I have used copious amounts of "smoke wrench" to loosen all sorts of metal assemblies by expansion, but this is mostly about softening the wood fibers.

    The heat transfer is not very efficient, so despite the glowing red rod I doubt the body of the screw gets above 300-400 degrees F. The thermal expansion coefficient of bronze is .0000097 of an inch per degree F. Anybody want to calculate the expansion of a .164 diameter screw in that temp range? I get .00291, about the diameter of a human hairdiameter of a human hair. Pretty insignificant in a squishy material like wood.

    Grrr... it wouldn't show the preview, so I couldn't tell if the link was set up right. Now I can't edit it.

    I've been doing that for a long time, but with plastics. Instead of heating up a metal rod with a torch, I use my soldering iron.

    1 reply

    Please note that this specifically references wood-screws. Wood is a different material, the effect of heat is differeent. And you need much more heat too. However, I too have used the soldering-iron on plastic, it works - you could post an instructable?

    This is generally applicable. I spent quite some time roasting an iron gate post peg with a blow-lamp, to get it out (succesfully). Although whacking with a hammer is a good first option.

    Does this work with tiny torx screws found in hard drive cases? I broke my only tiny torx bit trying to get one of those buggers out, and using TiN bits took forever to drill them out. And my screw extractor didn't work because it could not get a grip in the screw. Perhaps these screws were hardened.

    2 replies

    drill them out, just get the right size drill bit and take the head off. but no if you want to keep the hard drive. also, be careful when you're doing it, i slipped on the last screw, (i was trying to get the round thingy out) cracked my expensive bit in half and gouged a huge hole in the disc.

    It might be worth a try, but the real goal with metal pieces would be to heat up the part the screw is imbedded in (like with a torch), thus making the hole expand just that little bit. Not really an option with a hard drive frame. That said, I can't see much risk in trying this method in that situation. You'd surely want to let the screw cool back down, but the differential heating just might loosen things up. Plus, it will break the bond of any threadlocking compound that might be in there. Let me know how it works.

    Yeah it will probably come out easier if its cold because the screw will shrink a bit when cooled

    1 reply

    Oh, I don't think they're getting hot enough to expand significantly. I was just meaning to convey that they do not freeze back up when they cool. I didn't wait longer than it took to turn off the torch and pickup the screwdriver, and yet the screw was barely warm when it came out.

    Old tips are good tips. Is that a geodesic airolite boat?

    1 reply