rusted dial set screws

I use a product called " Kroil" made by KANO I ordered a 8oz can from amazon I use this when i tear down 100 year old Guns , watches and other smellier delicate items my last replace my last can because it started sneaking out of the can but it has never harmed any thing i have used it on but may not be good around plastic a drop on a screw and patients should do the job mild heat also helps may take repeated applications over a few days.

 

Ok. You cannot use Alum because you cannot remove all the steel.

You can try heat with a soldering iron, Kroil, and ultimately you can drill out the centers of the screws and use a broach or screwdriver to back out the threads. Sometimes it just gets ugly.

 

Tracker
Having worked with many rusted parts over the years, the most effective method of disassembly has been heat.

However it is a process that must be understood and one must be properly equipped for it to be effective. When working with threads, either the male or female thread must be very rapidly heated to a much higher temp than the mating thread and very rapidly cooled. This allows one or the other thread to rapidly expand faster than the other breaking the thread loose. Rapid cooling creates additional movement further loosening the the thread contact. Methods that slowly heat large surrounding areas that then slowly cool generally have little to no effect since any expansion and contraction effects the whole assembly in an equal manner. Thus no differential is created.

My personal method on a dial screw is as follows.

The first critical thing is to use equipment sized for the job. The first attached photo shows a .050" (1.2 mm ) OD diameter oxygen/acetylene torch tip in relation to the dial screw area of a 18s movement plate. The OD size is critical in allowing one to be able to visually apply the heat in the exact area needed. While there are others, the torch tip in the photo is a #1 tip from a Smith O/A little torch (USA made not the Chinese knock off) . For this application, I generally use either the #1 .003" or the #2 .006" orifice size tips.
The second photo I have shown before, but illustrates the flame size utilized again for this type/size application. The pen is a UniM .5mm ball point for size comparison.

In use, the 5200 degree micro flame is applied in a straight line over the screw (third photo/sketch) for about 2 to 3 seconds and rapidly removed before the heat has a chance to expand outward. Once the the torch has been removed, the surrounding area very rapidly absorbs the heat from the small area it was applied. This in turn creates the rapid expansion and contraction of the female thread cracking the thread loose.

If they must be drilled, the screws are often hard and the slot complicates spot drilling for center drilling the screw. This work I do in a small milling machine utilizing a special micro carbide center cutting endmill to create a center spotting cavity. I can explain in detail if someone wishes.

Jerry Kieffer

 

Tracker,

The dial is on the watch.

Aside from the fact that use of a torch on a watch is never needed, this is the second time I have seen the use of a torch suggested to someone who is less skilled (why else ask for help on such topics) without explaining the risks involved.

If heat from a soldering gun is not going to loosen the threads, neither is the torch. The issue is heating the surrounding brass or nickel to expand it, which has a faster rate of expansion than the steel screw.

Given that the dial is still on the watch, not only does the torch present risks to the steel parts and possibly gilt finish, it poses risks to the enamel dial he is trying to save and may well undo the feet.

What works on clocks or models may not directly translate to timepieces that are important or composed of hard to find original parts. A timepiece is in the most danger when it is in the hands of someone servicing it. Everything done by a professional watchmaker is about mitigating those risks while doing the job.

I think the advice offered in post #4 is fraught with problems and personally, in 40 years, I have NEVER used a torch near a watch.

 

Dewey
The procedure in post #4 is utilized as a method to protect what is worked on where required and the dial remains at room temperature through out the process as publicly demonstrated occasionally at National and Regional shows. However, to understand options such as this, requires a understanding of current technology and its capabilities. This type of information is often request by beginners and experienced for future reference and evaluation. While a very safe and especially clean method as publicly demonstrated, I personally cannot imagine getting a filthy soldering iron within ten miles of a watch movement. Not to mention the mess to clean up.

If some procedures and personalities are offensive, I would suggest you contact the Moderator.

Jerry Kieffer

 

Not sure why my disapproval of this suggestion should cause you such anxiety.

Given my reply was directly addressed to tracker, and that no mention was made of you at all but to the pitfalls of your suggestion, it would seem you are trying to manufacture some personal animus out of my warnings to readers.

I have nothing against you personally Jerry. I just think some of your suggestions are nonsense and in this particular instance downright dangerous to the piece. And I have no problem expressing my opinion backed by a rationale. What works with models and toys does not automatically transfer to situations that involve pieces where the goal is to maintain as much originality as possible. And in this particular case, I already outlined the considerations which you failed to appraise a learner.

I am not even sure you bothered to note the dial was still fixed and it was the dial Tracker is concerned about. If the dial was off, then the obvious choice would be to remove all steel parts and soak in Alum or acetic acid. Heat would not even have been on the list!

Bad advice is bad advice and needs to be pointed out as such, no matter how much the giver may be embarrassed.

These threads are read years after originally written and the content is what is important. I am most concerned that future readers have as a complete a picture of the issues under discussion as possible. It is not my concern if you are bothered by that.

 

Gentlemen!

As much as I appreciate the advice, experience and diversity of you and your suggested and preferred techniques, please keep it civil. If there is anything that will make a newcomer prone to not ask questions, and thereby go about their own uninformed and potentially harmful ways in regards to Watch movements, it's an inflamed discussion climate.

Regards
Karl

 

Before putting this thread behind, I would like to touch on drilling the screw if required as referenced in post #4

For most, I suspect drilling a .8mm to 1.0mm 18s dial screw is perceived as challenging to say the least. I also suspect the thought of drilling the hole down the center of the screw creating no damage to the thread, can be considered a nightmare. However, this depends on how it is accomplished.

At the very least to be successful, you will need a precision drill and a way to hold the movement and or movement plate. Personally I use a small Milling machine that is far more versatile and controllable as a precision drill. Ironically, the small mill is often less expensive than a quality precision drill.

The first photo shows a movement being held by a Lathe chuck mounted in the Mill. In this case, the chuck holds the plates to protect the dial rather than being held in a vise that may damage the dial.

From this point I have mounted a gage pin in a WW collet the same diameter as the dial screw head. This in turn is centered on the screw head under optics thus centering the spindle in relation to the screw. Second Photo.

At this point, the screw can now be spot drilled and then drilled. However, the slot in the screw can easily deflect small standard spotting drills causing the spot and drilling process to wander off of the screw center and often damage plate threads.
We are very fortunate in todays world to have all of the readily available tooling that in some cases was not available as recently as five years ago. To resolve the spotting issue, a carbide 60 degree Mill Drill has never failed to produce a centered pocket under the most adverse conditions. An example per attached link.
1/32(.0313) 2 Flute Carbide 60 Degree Drill Mill

Once a pocket has been machined slightly larger than the drill to be used, the drill has no choice but to drill down the center of the screw. Centering is the most important part of successful screw drilling. When drilling, the "Z" axis hand wheel calibration can be used to control drilling depth so as not to drill into the dial post. Drill sizes can be increased ever so slightly until the screw thread can be plucked from the plate threads.

Jerry Kieffer

 

Very sound and should be helpful to Tracker.

 

Product called "Break Free". -----used in gun repair etc.

 

This group is great. I just looked up the company; which product?

Thanks!

 

Break Free --CLP
Black plastic bottle with white print

 

Thanks for letting us know how the CLP worked. Were you able to save the threads on the third hole? At least you saved the dial and still have two dial screws to hold the dial.

Good work.

 

A little passion never hurt anyone,and I enjoyed it from you guys.
The proper solution was made clear. Thank you-this was a great thread.