Arrgh! stuck screw is being nasty.

Is this the right Alum? How is one supposed to use it. I have an old scrap movement with a busted bridge and rusted screw. The Alum does next to nothing other than to clean away the old rust. I let it sit over the weekend. All the water did was evaporate and leave the white stuff behind.

I went back to the screw extractor. Spending most of the day making a screw shaped pin for it. Grinding hardening and tempering a length of drill rod.

I then broke the set screw in the extractor tool.


I had some metric screws that fit.

The bridge screw is really hard.

I actually enjoyed making the extractor pin. Been planning to do this for months. Today was the fist free day I have had since late October. I first tried the new tool without hardening the drill rod (which was sort of hard to start with.) The bridge screw simply sheared off the tip. I re ground it then heated the rod to red hot and quenched it. The tip shattered. I then heated the tip again to red hot. Held red hot tip against the stuck screw to see if that would help. (I am concerned about the pallet fork if applying direct heat)

Reground the tip as shown, hardened it then tempered it to the amberish color & polished it.

This is when the set screw broke as I was torquing it with the back of an exacto knife in the slot.

I think this method would have worked with a normally tightened bridge screw. The bridge screw seems to be micro welded in place. Or friction welded chemically bonded or something.

Penetrating oil has sat on this for months, refreshed every now and then. That loosened the other screws. Not this one.

I tried heating the Alum over a 7W Christmas bulb (from a glass display that gets quite warm) Used a shot glass to heat water and the alum so the alum would dissolve. The old Atlas jar lid is where I do my application.



The drop just sits there on the test movement. (Hesitant to try it on the screw itself as again I am concerned with the pallet fork.)

I suppose I could attempt drilling The bridge out. The bridge is toast now that I got the new one, still seems drastic. I could also bend it like the old scrap movement to release the fork. Then get more aggressive with the Alum water. The eccentrics are still in place, so I can not dip the whole plate unless I remove them, which I may have to do to clean them.



One more microscope photograph. Showing the back side of the plate and how the extractor polished the end of the screw. I did attempt to put a drop of Alum water on this side. No effect.

I really want to get this screw out so I can (get the broken off screws out.) then start playing with all the replacement parts I have purchased over the last few months.

Side note. My micro torch sprung a leak. spraying butane and freezing the side as it leaked out. I got out the mapp gas torch which worked better anyway.

I did hold a can of compressed air upside down to see if freezing the screw made a difference. This is one stubborn screw.

I have had this movement 25 or 30 years. I got it because I got a bunch of booklets on how to repair chronographs. Wish I could remember how much I paid for it. Might have been part of a box of chronographs. I doubt I paid more than 30USD. I think I am 2 or 300 into it. Including my now broken screw extracting tool. This is the watch that keeps on giving.

I do, but the Alum I have is not working.

These threads may help:
https://omegaforums.net/threads/removing-a-broken-stem-from-a-speedmaster-crown.61416/
https://omegaforums.net/threads/basic-watchmaking-tips-replacing-a-balance-staff.96778/#post-1258367

I didn't "like" your post because of all the difficulties you are experiencing, but for the technical discussion, photos, and for your writing style.

Not being a watch maker, all I could suggest is either: get a bigger hammer or apply high explosives as needed.

Make sure the plate and screw are clean - not covered in oil or grease. Mix the solution as strong as you can - truly saturated and heating the water will allow it to absorb more alum. The alum you want is potassium alum, and that is typically the common alum found in the grocery store.

I looked yet again through the thread linked above https://omegaforums.net/threads/removing-a-broken-stem-from-a-speedmaster-crown.61416/

Photos do show the same grocery store alum. Does it loose potency over time? I see no bubbling or anything other than the surface tension of the drop.

Looks like I may be using too small of a drop. I was thinking it would act like an acid. The you tube video is deceptive. On re-watch I see that the plate is in the bottom of a jar. When I watched it before it looked like the movement was in air sitting on top of a petri-dish. Never trust a You tube video. :grin:

Cleanliness must be the issue. When one thing does not work I try another. Till I succeed or fail. If I fail, I will find something else to work on till I succeed. Why I can have so many project active at once. Although I do only like to have one watch apart at a time. A rule I am currently bending a bit as I keep getting parts for project watches. And have a number of watches I got in a disassembled or part disassembled state.

There is nothing I like better than an new watch as a box of parts to anticipate over. (Well not counting wearing the watch I put together myself.) Hint to Santa.

I did not always cycle this movement plate in the cleaner. As can be seen this movement has a lot of corrosion on it. Not quite a lump of rust but close. Applied liberal amounts of Kano Sili-kroil. Then I did soak it in tea to remove the loose stuff followed by a pass through the cleaner to remove any residue. The pallet jewels are a concern. So far they look OK as can be seen in the microscope photo.

I did give the area around the screw a quick cleaning with peg-wood before the first time I tried the alum. The Kroil soaks into everything. I have been cycling between the two methods as a point source. So mea-culpa. Things are not clean as they should me.

When I did attempt to heat the screw with a point source (the removal tool red-hot) the resulting oil and stuff did simmer, I did not attempt to remove this residual, which can also be seen in the photo. Note that I have only attempted a single drop of alum water as delivered the same way as an oilier would using a scrap screwdriver (which did not rust and probably covered with oil from the stone). This water/alum drop sits on top of the screw with surface tension till it evaporates.

I did not apply oil to the practice plate. I think I did cycle that through the cleaner. For someone who likes to work one watch at a time, I have a lot of 'parts' movements and scrap watches.

Currently the plate and bridge is once again soaking in Kroil as I was applying mechanical means since the Alum did not work as expected.

Looks like I am going to have to get aggressive and break the bridge to remove the pallet fork. That seems to be the only way I can really clean the plate to my liking.

Never had this much trouble with a Landeron, but I never had a Landeron this damaged.

Good thing I enjoy impossible challenges.

You forgot crowbar and rock drill.

I am looking forward to using the hammer. Which is a valid tool as the sweep chronograph hand is literally pounded onto the staff. (otherwise the stop/starting can cause it to work loose. I speak from experience.)

The part is submerged in the solution - that's where you are going wrong...

You can either remove all the ferrous materials you don;t want touched by the alum, cover them with something to protect them (grease for example), or suspend the part so only the screw you want to remove is in the alum solution.

Thanks for the confirmation. I had already come to that conclusion.

Not looking forward to removing the eccentric posts. (Better to pull them with a pin vice than twist them right?)

Everyone say goodby to the bridge, It was nice knowing you.

Better to press them out...I would use a Horia tool, but if you don't have that a Seitz tool, or staking set would work.

Thanks again for your wonderful (and prompt help)

I was thinking staking set. The back holes are a bit small. On the other hand I have the lathe (or 5) and some more drill rod. There is still mapp gass and the torch is out ...

A jewling tool is high on my list. My 'Military' Venus 170 is missing the chronograph bridge jewel. I also have a Landeron plate that the balance jewel is missing on. (found a whole new movement/plate but I find having an incomplete watch annoying even If it sits for 30 years forgotten)

Still need to get a Timegrapher (or fix the one I have.) Most of the tools I have from the 1990s came from friends or closed watch shop and dumped at NAWCC marts and date from the 1940s and 1950s. They probably sat around for 20 or more years till I came along.

Strange I do not feel old. Guess one is as young as one feels. I was pretty much the youngest member in the NAWCC chapter. The next youngest was 7 or 8 years my elder or mayby 12. Most of them were between 70 and 90. They were not an inclusive group. A lot of the reason I have not done anything for the last 18 years is I had no one to share this with. Or turn to when I got stuck.

The others my age were only interested in Rollexes and their retirement portfolios.

The world will never see their like again.

Too bad there is no Santa to put a Horia tool under the tree tomorrow. I seem to be more the absent minded fairy godmother. and once again I forgot to go upstairs for breakfast.

It is soaking on a Christmas tree light bulb.

The AS 1187 was a success. So successful it got it's own thread.

I did use the staking tool to remove the eccentric. The other part was a threaded screw. Of course as I was placing the eccentric into the parts tray, the tweezers decided to throw it somewhere. Hopefully it will turn up sometime. This is the eccentric for the hour register. That section is going to take a lot of work to restore. I think there are other broken screws in that section.

Most of the initial work is going to be on the timekeeping side. Curious the difference between this and the Landerons. Perhaps it is more that I have a dozen Landerons, and am more familiar with the parts. I think that this may be the first pillar wheel chrono I have done serious work on. Well the Venus 170s are pillar wheel, but they have the rocker bars.

There are so many variations and sub variations. No two watches even of the same caliber are the same.