Dealing With Difficult Screws - Hayulp

Jookyjr

It is the last day of the school holidays, and I still can't get one of the neck screws out of my Polish semi thing, and it is driving me nuts as I need to be playing it Wednesday night..

It is a big slot-headed (?) screw that looking at the one that did come out, will have gone rusty. Unfortunately, the screw head is mashed, it was mashed when I got it, but is even more mashed now and it is a really shallow bit where the screwdriver should fit.

So far I have tried:

1. A big screwdriver

2. Putting a rubber band over the screwhead to try and get more grip

3. Leaving it soaked overnight in WD40

4. Hitting the screwdriver with a hammer to try and deepen the slot

5. Heating the screw with a soldering iron to try and make the hole bigger

6. Hitting the screwhead with a chisel to try and deepen the slot

And it is still laughing at me.

I would try getting pliers or grips to it, but it is at the bottom of a narrow 2cm deep trench, so no chance, and there is a small metal neck plate thing it is sat in flush as well, so it isn't like I could dig under it into the wood even.

Reading around Screw Extractor tools seem to be recommended, but Homebase didn't sell such a thing earlier today, though there are plenty on-line.

Is that my best next step or should I just drill through the fretboard and hit the bottom of the screw with a hammer?

ecc83

Since you have already resorted to bashing, buy an impact driver.

If you have never seen one it is a heavy steel cylinder that takes various bits (you might have to grind down the one supplied to fit) .

Inside the block is a cam system so that when you smite it (lump hammer) it turns the bit a fraction of a turn and in general will shift almost anything. It might tear the head off the screw but then you should be able to get mole grips on the bolt.

Find a Rock Bottom type shop, just as good as Halfords for a one off job and a lot cheaper!

Dave.

Jookyjr

Thanks @ecc83 - I must admit I'm a bit reluctant to really give it a belt, as it is a pretty flimsy looking old semi acoustic. Also the hole where the screws are recessed is 35mm by 14mm and there is no way I could get mole grips in when I inevitibly knock the head off the screw.

I was wondering about some of these or the like, where one end you use to drill a hole in the top of the screw and the other then screws into that hole so you can use it to unscrew the bodged screw. Or something

http://ecx.images-amazon.com/images/I/71TFZEFn+GL._SL1024_.jpg

Phil_aka_Pip

Ronnie Barker had his methods

ICBM

Drill the head off - start with about a 2mm drill in the centre, go in about 5mm, and then work up through the sizes until you just exceed the shaft diameter (probably about 6mm), at which point the head should break off as a circle. You can then pull the stump through with the neck. Then use mole grips to turn the shaft and get it out - heating may also help here.

Obviously you will need to find a new screw afterwards...

Jookyjr

@ICBM said:

Drill the head off - start with about a 2mm drill in the centre, go in about 5mm, and then work up through the sizes until you just exceed the shaft diameter (probably about 6mm), at which point the head should break off as a circle. You can then pull the stump through with the neck. Then use mole grips to turn the shaft and get it out - heating may also help here.

Obviously you will need to find a new screw afterwards...

Ahh, I really should have thought of that, shouldn't I?

Thanks, I'll have a go at that now

Brains, dangerous

Jookyjr

@Phil_aka_Pip said:

Ronnie Barker had his methodsI tried his fork handles

No, I tried his fork handles and I couldn't see a thing

Skodadad

Know anyone with a welder? Cut some foil and protect the body around the screw. Spot weld on an old screwdriver and turn? I'd be concerned about snapping the screw, you may not get many more goes at it. Good luck

Phil_aka_Pip

The phrase "Easy-Out" came to mind

http://www.screwfix.com/p/screw-extractor-5-piece-set/18643

ecc83

ICBM said:

Drill the head off - start with about a 2mm drill in the centre, go in about 5mm, and then work up through the sizes until you just exceed the shaft diameter (probably about 6mm), at which point the head should break off as a circle. You can then pull the stump through with the neck. Then use mole grips to turn the shaft and get it out - heating may also help here.

Obviously you will need to find a new screw afterwards...

That's what I meant about the head snapping off, you could pull the neck through it. And sorry, did not realize it was a semi ack!

Yes, try IC's drillin' but! FFS go out and buy brand new bits and spend a decent wedge on some good ones. B&D used to make a "bullit" drill bit that auto centred. Actually you should be able to find a bush or similar that will go into the hole and keep the wee drill centred. Maybe a nut with the corners filed off a bit?

Dave.

Rocker

Yeah, do it as @ICBM said. And wear safety glasses *important in case something shatters**

Sarge

If all the above fails, try a plug cutter bit, and fill the hole with dowel or similar.

Jookyjr

Thanks everyone - going to buy some new bits, try and find a Bullit drill bit, and dig out the safety spex.

Then I think I'll get my little sis to do it

More annoying questions tomorrow no doubt

Nomad

Big screwdriver held in the slot, pushing down and applying some torque in the loosening direction. Tap the other end of the screwdriver with a hammer. The small shocks from the tapping can be enough for the torque to get it to start turning.

ThePrettyDamned

Rocker;841120" said:

Yeah, do it as @ICBM said. And wear safety glasses *important in case something shatters**

Having had a tiny screw for a string tree explode while doing this, I can attest that this is very sound advice indeed.

TimAl

Also try TIGHTENING it a bit - as that can break the 'seal' . . .

dern

WD40 is not an effective penetrating fluid, try and get something made for the job like plusgas or halfords make their own. From years of working on cars it'll make a huge difference if penetrating fluid is going to help at all.

Getting some heat into it might help too. I don't know where the screw is but if it isn't that big then holding a more powerful soldering iron on it for a bit is a relatively safe way to direct heat into a screw without burning anything else.

Regards,

Mark