Removing stuck screw in a 1940's Mechanical Eska

[brik1111]

Hi all,

I'm having a crack at fixing an Eska that's not running, but I haven't gotten very far yet because of a screw that's stuck in place. The problem screw is the one below the word "co", and while the others of the same size happily turn (with a brand new screwdriver), nothing will budge this one. I did some research and some sources recommended using either WD40 or a soldering iron to loosen it, but I've tried both without any luck. Is there something obvious I'm missing here in order to remove it? Or does anyone have any tips? Greatly appreciated.

[Nucejoe]

Remove the other two screws on the train bridge, this will alter pretension,

Remove as much of the movement , balance bridge , fork, ratchet , barrel and date ring plate on the side.

NO TAPPING on the screw head ,this may weaken the screw structure gets it ready to break ,pops the head off.

Apply penetrating oil on top of the screw generously and the other side ,,Thread,,

Let soak for day or two. 

Rust killer like WD40 or B12 should applied from the gap betwwen the train and main bridge.

Try to unscrew, no excessive force.

If didn,t work, try soaking in kerosene for few days, dose miracles.

Heat damages the screw and its plating, if you got to that stage apply heat with soldering iron touching the screw only and from the thread side.

Good luck.

 

[oldhippy]

Alum is what you need for removing broken or rusted in watch screws. There's plenty of info on the net on using it. 

[yankeedog]

as 1187/94 movement, common and robust they respond well to a little TLC, what ever you do force nothing.I am sure old hippy is right about the alum. but I use a little penetrating oil on such things.

[Nucejoe]

Hi yankee   kerosene dose wonders. Just drop the movement in, let soak for few days.

I got a question for you,   is what Americans refer to as home heating oil, kerosene itself or what?

Regards joe

[yankeedog]

Home heating oil is closer to diesel fuel.In fact if you have an older non computerized diesel it will run on it.people do it, however it is not taxed for road use

[brik1111]

Thanks for the swift answers, everyone. A few follow up questions:

Would WD-40 be considered penetrating oil? I've tried quite a bit of that - leaving to soak over the area where the screw is for a day or so - and have had no luck removing it. If so, kerosene would be the next logical step, however (and this might seem like a dumb question) would that wreck the still attached watch face at all? Just wondering, since it will be completely soaked in it.

Alum seems like the nuclear option to me, but I'll keep it in mind if all else fails.

[yankeedog]

uh... yeah....you would really want to remove the watch face and hands.and yes WD 40 would be considered a penetrating oil. A friend of mine who once worked for the airlines said the only problem with it is that they could not dip the entire air frame in it..that being said an entire movement dip could cause you more problems than its worth. the problem is the stuff does not evaporate.If you want to dip it in anything use mineral spirits, which does. before soaking it also remove the balance and pallet assemblies, other than those two things , the dial and hands there's nothing really that can be hurt by a petroleum solvent

[vinn3]

Quote

 

  this forum is full of posts on those various subjects concerning "stuck screw".   it may be the first thing a watchmaker should learn. -  penitrating oil.   vin

[brik1111]

14 hours ago, yankeedog said:

uh... yeah....you would really want to remove the watch face and hands.and yes WD 40 would be considered a penetrating oil. A friend of mine who once worked for the airlines said the only problem with it is that they could not dip the entire air frame in it..that being said an entire movement dip could cause you more problems than its worth. the problem is the stuff does not evaporate.If you want to dip it in anything use mineral spirits, which does. before soaking it also remove the balance and pallet assemblies, other than those two things , the dial and hands there's nothing really that can be hurt by a petroleum solvent

The problem is, I can remove any of that stuff because the stuck screw is in a critical place, holding the top plate in. I've removed every other screw I can too and found another stuck one (to the left of the word "Swiss") which is holding the other major plate in.

[AndyHull]

Gentle "percussive maintenance".  A GENTLE tap with a hammer, via a softer metal to avoid marring the screw, (use a brass or aluminium rod, to direct the blow where you need it), may loosen the thread. It may also break off the head, depending on how damaged the screw is, so I offer no warranty what so ever with this advice.

Obviously protect any sensitive items that may be affected by this rather invasive treatment. Tappy-tap-tap, rather than a monstrous whack is the order of the day. The object of the exercise is to crush and loosen the corrosion within the thread, not to destroy the screw. 

Failing that, drilling or dissolving the screw are the only options I can think of if penetrating oils have not made any difference. Corrosion can be an amazingly strong glue.

Edited December 4, 2018 by AndyHull

[AndyHull]

.. I presume you tried a slight tweak in the wrong direction, as this too can sometimes loosen whatever is binding the screw. Not so hard as to mar the screw head obviously. Also ...  lefty loosey, righty tighty, mostly. Its pretty unlikely, but could the screw be threaded backwards, just to annoy us? More likely I'm over thinking the problem.

Edited December 4, 2018 by AndyHull

[Marc]

7 hours ago, brik1111 said:

The problem is, I can remove any of that stuff because the stuck screw is in a critical place, holding the top plate in. I've removed every other screw I can too and found another stuck one (to the left of the word "Swiss") which is holding the other major plate in.

The two stuck screws that you mention should not prevent the removal of the dial and hands, or the balance and pallets.

The hands should just pull (lever) off. Look for two radially oriented screws in the side of the movement to release the dial feet and then the dial should just lift off. Remove the balance cock screw and (gently) pry up the balance cock, allowing the entire cock/balance assembly to be removed which will give access to the pallet bridge underneath. removing the pallet bridge screws will allow you to pry off the pallet bridge and remove the pallet. You will then be able to dunk the entire movement into the penetrating oil of you choice without fear of harming the dial and hands or the balance or pallets.

[oldhippy]

If you use alum which I suggested it eats away the screw. Just a little alum on top of the screw, you will need to do this many times until you can lift the plate off and remove the rest of the screws. You might be able to just unscrew the rest. It is no good hammering as you will damage the treads in the plate.

[yankeedog]

sure you can remove the dial on one of these. its a piece of cake. look around the perimeter of the movement , on its edge. located at about 2 and 8 o,clock you will find the two screws that hold the dial in place. I have worked on a few of these movements, i would not steer you wrong. loosen them one or two turns, you don't have to take them out..8mm screw heads

 

[brik1111]

On 12/4/2018 at 8:43 PM, Marc said:

The two stuck screws that you mention should not prevent the removal of the dial and hands, or the balance and pallets.

The hands should just pull (lever) off. Look for two radially oriented screws in the side of the movement to release the dial feet and then the dial should just lift off. Remove the balance cock screw and (gently) pry up the balance cock, allowing the entire cock/balance assembly to be removed which will give access to the pallet bridge underneath. removing the pallet bridge screws will allow you to pry off the pallet bridge and remove the pallet. You will then be able to dunk the entire movement into the penetrating oil of you choice without fear of harming the dial and hands or the balance or pallets.

 

On 12/4/2018 at 10:33 PM, yankeedog said:

sure you can remove the dial on one of these. its a piece of cake. look around the perimeter of the movement , on its edge. located at about 2 and 8 o,clock you will find the two screws that hold the dial in place. I have worked on a few of these movements, i would not steer you wrong. loosen them one or two turns, you don't have to take them out..8mm screw heads

 

Are the screws to release the dial stuff shown in these photos? If so, I'm going to need a smaller screwdriver lol

[brik1111]

On 12/4/2018 at 9:24 PM, oldhippy said:

If you use alum which I suggested it eats away the screw. Just a little alum on top of the screw, you will need to do this many times until you can lift the plate off and remove the rest of the screws. You might be able to just unscrew the rest. It is no good hammering as you will damage the treads in the plate.

 

Looks like I will probably be doing this if all else fails. I'm not restricted by time though, so if I can get it out without any destructive means it would be preferable

[Marc]

7 hours ago, brik1111 said:

Are the screws to release the dial stuff shown in these photos? If so, I'm going to need a smaller screwdriver lol

Yes, that is one of the dial feet clamping screws.

watch this 

https://www.youtube.com/watch?v=ETrou04lH8w

then loosen the screw in your pic and you should find another one in the opposite edge of the movement, loosen that one as well (just a couple of turns should do it, (try not to remove the screws completely as that reduces the chance of loosing them) and the dial should just lift off.

Once the dial and hands are out of the way remove the balance cock/balance wheel assembly as one whole unit taking care not to distort the hairspring, then remove the pallet bridge and the pallet fork. Put all of the removed items in a safe place.

What you have left can safely be dropped into a bath of WD40, kerosene, paraffin, petrol, IPA, etc. or any other non-corrosive solvent without risk of damage.

If you do go down the alum route you will need to confine the alum to the screw head in question as OH said. Do not dunk the whole movement into the solution as it will dissolve all of the screws, pinions, pivots, springs, etc. anything made out of steel.

Edited December 6, 2018 by Marc
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[brik1111]

Thabks Marc, very useful information. I'll source a smaller screwdriver and report back

[yankeedog]

Those are the screws. they clamp down on the dial feet, which are actually tiny posts attached to the dial .This watch does not look rusty, so they ought to back out without any problem, just don't get mad at them . 

[Nucejoe]

Yankee is right, shouldn,t get mad ,dial feet break easy. That screw will come out.

Thank you yankee, diesel fuel are not taxed here either, there are so many grades ,improvement to comply with new standards, so if you know the old grades kerosene , that would do wonders as one cleaning solution for gumming removal etc.

Best wishes to all.

[yankeedog]

I think any kind of refined petroleum would work as a general solvent..anything that readily evaporates.you just have to be careful and not Set yourself on fire

Edited December 6, 2018 by yankeedog
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