Demon screws that won't budge

[ThornhillMike]

Morning all
In between the new roof going on and various other remedial tasks, the temptation to start removing doors and window shutters to strip took over. Which led me to the inevitability of 'that screw' which will not budge at all. All hinges were caked in layers of gloss paint, so that was the first job. As ever, there's always one (on some there are three...) that refuses to leave.
I've tried brute force (my own), I've tried power, I've tried the not so subtle whack with a hammer, but all to no avail. The screw head appears far too tight for something like WD40 to have any effect, but that's next on my list.
Anyone have a successful trick for removing these?!
Thanks

 

[Stevers]

You could try tightening them ever so slightly to release them.

If you go down that route, only the very lightest of caustic dips or you'll damage the joints.

 

[a twig]

Step 1) WD40
if that fails
Step 2) Let the impact driver loose on it
If that fails
Step 3) Kitchen blowtorch, heat up the screw, let it cool then have a go
Failing that
Step 4) Angle grinder to cut the hinge away from the screws and then use molegrips to attempt to extract what remains of the screws

If you’ve resorted to step 3 or 4 you usually need to mount the replacement hinge somewhere above or below the old one

 

[Cubist]

If you have a small electric soldering iron - apply it to the head of the screw for a few minutes until the screw gets hot then let it cool for a minute or so and try to turn it. If that doesn't work repeat the heating and then 'shock cool' the screw with a jet of water.

Also, if you can get and adjustable spanner/grips on the handle of the screwdriver while you are leaning into it to apply pressure the extra leverage can be a big help.

 

[ThornhillMike]

Step 1) WD40
if that fails
Step 2) Let the impact driver loose on it
If that fails
Step 3) Kitchen blowtorch, heat up the screw, let it cool then have a go
Failing that
Step 4) Angle grinder to cut the hinge away from the screws and then use molegrips to attempt to extract what remains of the screws

If you’ve resorted to step 3 or 4 you usually need to mount the replacement hinge somewhere above or below the old one

Thanks Twig. I'm really keen to avoid any 'nuclear" options for the reason you highlight, disturbing the existing hinge seat. I'll try the 'hot & cold' treatment that you and Cubist have suggested. I have 24 doors and 16 pairs of shutters involved, and I'm only 6 doors and 3 pairs in (success wise), so I need a repeatable solution!

 

[Cubist]

And when the worst happens and you twist off the head of the screw leaving the shaft in place - you can use a 'plug cutter' to reveal more of the shaft and once you've dug out the remains fill the hole with a length of dowel. However, you do have to be prepared to sacrifice the plug cutter.

 

[Craig89]

The key with slotted screws is to get a really well fitting screwdriver, I would adjust it on the grinder if required. Preferably a screwdriver with a square or hexagonal shank should be used so a spanner can be used to apply more torque. Impact screwdrivers that you hit with a hammer and they apply torque when you do, can be useful but can be abit aggressive on slotted screws, same applied to battery powered impact drivers

 

[CliffordPope]

I've found the secret with an impact driver is to twist it hard anticlockwise to take up any slack, press hard against the screw so the bit has no tendency to jump out and burr the slot, and then wack with a heavy hammer. Once it moves a fraction apply a penetrating oil (WD40 is not a penetrating oil) and try moving the screw back in again with an ordinary screwdriver.

If that fails then try a small sharp cold chisel at an angle at the end of the slot, or if all else fails, chisel off the screw head.

 

[ThornhillMike]

Thanks for all the replies. The hot/cold trick didn't seem to budge them. I managed to get about half out with brute force and some cajoling (with a hammer), the rest had to be drilled out. At least some shutters are off (two pairs), but the seating is a bit messy in places. I'll look to resolve that when they're ready to go back up.

 

[fernicarry]

A multitool with a smallish blade in the slot has worked for me with old pulley screws. I think the vibration helps break loose the layer of rust from the screw shaft.

 

[RBailey]

I recently made this abomination so that I could use a decent sized flat head in a standard hex bit driver. (It started life as an 18mm spade bit with some grinding and heat treatment.)

 

[Cubist]

Fundamentally though, once you get past the donkeys years of paint and have good access to the screw head, the big problem is the corrosion of the screw shaft resulting from all those years of contact with the wood tannins. I for one, like many others I suspect, have never been able to resist applying muscle to free them and inevitably end up breaking the shaft of the screw at some indeterminate depth inside the frame. Hence, being a lover of symmetry in all things, and three new screws in a four hole hinge plate is just not acceptable, I've wrecked more than one plug cutter while excavating the remains of the old screw.

But what drives me completely nuts though is how often one finally gets a stubborn screw out only to find it was bent when it was first driven into place!

And don't get me started on cross or stripped threaded nuts and bolts.

 

[RBailey]

I've wrecked more than one plug cutter while excavating the remains of the old screw.

You can get very cheap hollow diamond tile drill bits that work well as they can handle the steel as well and their hollow nature means they "follow" the screw.

 

[Toby Newell]

Morning all
In between the new roof going on and various other remedial tasks, the temptation to start removing doors and window shutters to strip took over. Which led me to the inevitability of 'that screw' which will not budge at all. All hinges were caked in layers of gloss paint, so that was the first job. As ever, there's always one (on some there are three...) that refuses to leave.
I've tried brute force (my own), I've tried power, I've tried the not so subtle whack with a hammer, but all to no avail. The screw head appears far too tight for something like WD40 to have any effect, but that's next on my list.
Anyone have a successful trick for removing these?!
Thanks

View attachment 10997

Glad to hear you are sorted now.

In future (for wood)

1. Heat will do little, that is for metal/metal interactions same with WD40. For massive hinges both may be corroded together but normally the stubborness is due to tannin corrosion in the timber turning the screw into an expanding penetrator.

2. THE no. 1 most important criteria is the best fitting bit / screwdriver end, this goes for all head geometries but especially for slotted. Otherwise you will simply burr the slot.

3. To maximise #2 always carefully clean the screw head to ensure maximum depth.

4. Buy the highest quality screwdriver / bits you can. I still have most of the Wiha gold plated- diamond coated bit set I bought 25 years ago, minus all the flat heads that twisted / broke! I have hundreds of bits, just buy multiples of quality bits in all the sizes, you should have several different, brand new slotted bits just for this purpose.

5. Hold (and maintain) the bit as close to ZERO degrees to the screw head as you can. The screw might be skewed, so take note and adjust your position, you want all of your compressive force to run down the centre of the screw.

6. Apply as much downward pressure to the screw as you possibly can, be careful, when screwing this can result in a maximal effort and with a twisting motion be very dangerous for a weak back. You need a ladder or step up to move to the height of the screw so you can use your bodyweight.

7. Use the correct tools! Impact drivers are pointless for screwing into wood, marketing gimmik as they are cheaper to produce (hammer cheaper than planetary gears) I use 10,000 - 30,000 screws a year, 98% with my Bosch 12v drill drivers with German Wera adaptors and bits. Impact driver will bounce out. Parallel force is equally as important as turning force.

Use a manual screwdriver! I use a 300mm hexagonal shaft Wiha that flexes in torsion to avoid slippage, you can see it twist as it transfers force, the extended length gives you more torque. Putting a spanner on the hex shaft is a gimmick, unless you have a second person to help as on your own you won't be able to apply enough parallel pressure, besides, at full force the shaft is so twisted in torsion the spanner may not fit properly. Spanners on hex shafts are only goid for shorter lengths where you cannot apply as much torque / pressure from above.

8. Technique: Before you start clean the head. Tap the head a couple of times carefully with a nail punch to break any metal / metal connection to the hinge. If the head is still a loose fit then put a small square of clean washing up glove inbetween.

Apply maximal force, up to and including full bodyweight ( be careful, I repeat, this can destroy your back) down through the centre of the screw, then, maintaining pressure, carefully turn the screw slightly clockwise (ie tighten - lefty loosey, righty tighty) Then try anticlockwise. Repeat until you can loosen more than you can tighten then continue to loosen, remember to apply downward parallel pressure as you apply rotation.

This method works much better than any impact driver, I don't own one! I gave it away to my mechanic friend. I have 8 x200mm construction screws which I put into 550 year old oak, admittedly I move up to my 18v driver for the really big ones but 99.99% of screws up to 130mm I do with my 12v drivers, not an impact in sight.

The main risk is the slot will burr or your bit / head will twist or snap then you will have to drill, a secondary risk is the head will snap off!

You need to buy a very long screwdriver, I use one with a bit holder, then buy a large selection of bits, ck, wiha, wera do sets, use a new one!

You may have guessed I am quite Jimi Hendrixed (experienced) I hate slotted screws with a passion! I can eat them with my sanders but that's a fire risk if there are loads of them, it can take hours to remove them. If you need to drill them then a carbide or diamond coated rasp can help. Removing the shaft with a snapped head will often make a big mess.

Anyone who uses slotted heads these days should be publicly shot. Unless of course they are brass and they line up the slots.
Wiha 300mm bit driver. Will beat 100% of your drills / impact drills / impact drivers 100% of the time ( in wood) all bets accepted

 

[Toby Newell]

Thanks for all the replies. The hot/cold trick didn't seem to budge them. I managed to get about half out with brute force and some cajoling (with a hammer), the rest had to be drilled out. At least some shutters are off (two pairs), but the seating is a bit messy in places. I'll look to resolve that when they're ready to go back up.

View attachment 11014

lovely windows btw

 

[ThornhillMike]

lovely windows btw

Thanks Toby. Scarily there's 57 of them in total, not all with shutters thankfully. My frustration is that I've only currently managed to remove 5 pairs (wearily!). Still 11 pairs to go... Then on to doors. I've got 10 off, with another 11 to go. The ground floor was slow, but the next floor is the one where nothing will move screw-wise. The screws that have emerged have all looked 'rusted', but I suspect all result from being in the frames for nearly 200 years. I will try your very complete guidance notes and persevere.

Then only upside is that when eventually off, they do clean up pretty nicely...

 

[Toby Newell]

Thanks Toby. Scarily there's 57 of them in total, not all with shutters thankfully. My frustration is that I've only currently managed to remove 5 pairs (wearily!). Still 11 pairs to go... Then on to doors. I've got 10 off, with another 11 to go. The ground floor was slow, but the next floor is the one where nothing will move screw-wise. The screws that have emerged have all looked 'rusted', but I suspect all result from being in the frames for nearly 200 years. I will try your very complete guidance notes and persevere.

Then only upside is that when eventually off, they do clean up pretty nicely...

View attachment 11036

View attachment 11037

57!!! They do look amazing, although my preference would be to paint.

Do not worry about the effort, it sounds perfectly normal.

I have screwed several hundred thousand screws, albeit mostly in, but the same rules apply.

Impact drivers are a scam and pointless for wood. The impact force simply gets absorbed by the wood rather than being transferred, also the jolt means more risk of camming out. Joe public (including most trades) are too lazy to work it out, and it becomes herd mentality, they are simply a joke, lol. If you look you will see impact drivers (not wrenches!) are the cheapest tools a company makes, they often like to pair these with a cheap drill driver in a set as a loss leader to hook you into their battery eco system, oh and their expensive 'torsion bits' I have neither and remove screws no impact driver even can, total marketing bollox. A cast rotating hammer and spring are cheaper to make than complicated planetray reduction gears and provide massive torque numbers. Let's face it, most people are too lazy / dumb to work out how a tool works, they simply look for the highest number, 'look Martha! it's 3 million foot pounds and only £49.99!'...They actually are annoyingly loud and can damage lathe and plaster. Amusingly, utterly pointless and slightly detrimental, if anyone thinks they are better than a normal drill-driver then they simply don't know how to use one, same rules above apply, good bits, good holders, maximum parallel pressure.

Anyone reading this selling their impact driver and buying a £25 Wiha 300mm bit driver will be pleasantly surprised and the only annoyingly loud noises will be coming from your body

Rant? Possibly, but this knowledge is a game changer.

It's also great fun when a builder gives up after hanging off the end of max volt power Mawaltkee 3 million foot pound impact to waltz over with your Wiha and unscrew it by hand... 'there you go'.

As I said, if I have a stubborn screw most times (and 100% of the time with slotted heads) I try to remove them / tighten them by hand, much, much safer.

I know it can be counter intuitive that a human arm can apply more force than a pointlessly and deceivingly highly rated torque machine, but there you go!

I would emphasise the need to push with all your might to keep the bit engaged, then slowly turn with all your might! It's a recipe for hernia or back damage, so it's not easy or fun! But it is the most effective method. I have removed screws after gorillas have attempted with their 18V high torque nothing burgers.

Just be prepared for your bits to bend / break, screw head to burr or snap off, nothing you can do!

One or two layers of washing up glove or part of rubber band can sometimes help, much like in opening a pickle jar. (for horizontal screws you can even scrape some 80 grit abrasive into the slot)

Machining your own or griding down a larger bit can be great, you really want as large a bit as possible with the closest fit, not sure about the heat treatment though! Hard = brittle = snap.

Removing a screw with a snapped head is another kettle of fish! You often have to hack it out. Sometimes you can hack at the top and try and twist it out but this often doesn't work. Normal pliers are close to useless, I have tried hundreds of pounds worth of tools, mole grips don't usually work either. Japanese made Neji sauraus are better than normal pliers but frankly prerty poor quality for a Japanese tool, mine got damaged on first use. The best I have found are from Knipex, I have the whole range. I would also get a pair of their pincers and bolt cutters.

The Knipex twin grip slip joint pliers are probably the best in the world. I have removed several hundred thousand fixings with my various Knipex and selection of Japanese cats paws. Actually you can remove screw shanks with those too sometimes, the steel is so hard it bites in, even to screws, just remember not to cheap out, you MUST only buy Japanese, ie Bakuma, Ice bear, Mokuba, Shark Grip or the Japanese made Estwings.

Drilling around is often the best option.

If you leave a big hole (you will) then a two part epoxy repair resin / filler (I get mine from 3C Sealants) will give you a firm hold, although you may need to pilot drill with a tiny bit.

 

[Toby Newell]

But what drives me completely nuts though is how often one finally gets a stubborn screw out only to find it was bent when it was first driven into place!

that ^^^ should definitely go in the grump of the day section...

 

[Toby Newell]

And when the worst happens and you twist off the head of the screw leaving the shaft in place - you can use a 'plug cutter' to reveal more of the shaft and once you've dug out the remains fill the hole with a length of dowel. However, you do have to be prepared to sacrifice the plug cutter.

my £55 Japanese wood owl plug cutter is going nowhere near a rusty screw!!!

As someone else said, a cheap diamond / cabide rasp / hole saw or the smallest wood hole saw might be just as useful, unless you like risking damaging good plug cutters! Also I have always found cheap plug cutters to be totally useless I guess which wouldn't be helped possibly rubbing against a screw, but right idea.

 

[Toby Newell]

You can get very cheap hollow diamond tile drill bits that work well as they can handle the steel as well and their hollow nature means they "follow" the screw.

this ^^^