Repair Notes

[Ray Fanchamps]

Would anyone be interested in developing some repair notes to present here on these boards? After discussion perhaps they could be edited and archived into an interesting resource.
I believe our members knowledge is a valuable resource and I would like to find ways to access that knowledge and promote sharing the same.
I have included my "first efforts" below in the hope that it will encourage many of you to improve on those notes with some of your own that you value.
You can choose any topic area, this is just an experiment to get you all thinking about sharing that special area of knowledge you have that others might benefit from hearing about.
I will include my effort as part of a trilogy. "Before, during and after".
My first effort will focus on some thoughts on how I approach the "Before" aspect of a repair.

Before.
Any repair process starts with a close inspection of the complete movement prior to pulling apart. Even a clock that "just needs cleaning" can reveal some surprises. The rebuilding process should be just that, all the "innovations" of previous repairs will have been removed where possible. Any problems noted and repaired so the rebuilding process is an assembly and adjustment process performed on clean fingerprint free, swarf free and filings free parts. By close inspection when tearing down one can anticipate the required work and perform the repairs ready for a final cleaning prior to re-assembly. Discovering problems on re-assembly often means once again disassembling, carrying out the repair, re cleaning and starting to rebuild again.

Even if you think you "know the problem" a good pre-teardown inspection will reveal other matters that need attention prior to rebuilding.

Newer clocks often have worn bushings, after some time one gets familiar with where to look for expected problems on specific units. On a clock that has broken springs it is a good idea to look for broken teeth, bent arbors or pivots. Many antique clocks were so well made they survive just fine on infrequent cleaning and oiling but many clocks have stopped and been made "operational" again through "innovative adjustments". Those changes should be noted and plans made for their removal. Check the operation of any levers and actuating mechanisms, often overlooked since it's the wheels and train that are often seen as the problem. Bent or damaged levers, especially those between the plates can be a cause for extra work if undiscovered until after the rebuild.

Check that trains operate as they should, finger power should work most trains enough to check a chime or strike cycle or make an escape wheel go around one cycle. Even very close inspection when apart might not reveal a problem that is readily observed when all related parts are seen working together. The time to check those relationships is before tearing down. Its too late to guess what those relationships were when you are rebuilding.

When checking those relationships prior to teardown don't be fooled by what you see. The previous person may not have got it right either. You should always understand the mechanical operation being performed. Even if you have never seen such a movement before, it is only by understanding the operation that you will be able to successfully rebuild any movement. If the movement is not familiar to you take some time to look at the movement and watch its operation or try to cycle it through some operations and be sure you understand how it operates and the relationship of one train to the other(s). If an operation is not performing correctly be sure you understand why. On most clocks the "why" should be lack of lubrication or excessive wear. Look for signs of wear and add "finger power" to overcome poor lube and see if that overcomes the problem. On a worn part or area try moving the loose part back into its original position and see what changes.

The key to success is not that you are familiar with any particular movement, rather it is that you understand the mechanical operation being performed and that comes from careful observation of what you have in front of you. When you find a problem be sure it is a problem and not your lack of understanding the process. Often clocks are "changed" from the original configuration into "something else" based on the clock not performing as expected or not "looking like ones seen in the past". A recent example I came across was confusion over a silk suspension. The owner restrung the clock, mounted the pendulum and found the pendulum would only mount "crosswise" to the expected position. The remedy was to clip off the end of the pendulum and put a new bend on the end to make the pendulum orient the correct way. Sharp observers will note that this would make the clock out of regulation but what else is to be learned? This individual "restrung" the suspension as he thought it should be and then changed a manufactured part to fit changes of his doing.

It is rarely a good idea to change a manufactured part to "fit" or "work" with a part that you have changed, knowingly or otherwise, from the original. Slight "bending" is one thing but filing, cutting or "adding " is often performed due to a lack of understanding of the mechanics. It is poor practice to change a clock from its original configuration in the first place but be sure to understand that if you are making substantial changes to original parts you probably are doing something wrong. Never change an original part to make it fit your changes. Rework your changes to make them work correctly with the original parts.

A good understanding of the mechanism in front of you will aid in the rebuild. A good inspection prior to teardown will limit surprises when rebuilding and reduce "comebacks". This will also reduce the possibility of your own clock sitting on a shelf no longer running a few days after a repair..

Please feel free to comment and let me know if there is any potential value to such notes.

Ray Fanchamps


[This message has been edited by Ray Fanchamps (edited 12-19-2000).]

[Ray Fanchamps]

Would anyone be interested in developing some repair notes to present here on these boards? After discussion perhaps they could be edited and archived into an interesting resource.
I believe our members knowledge is a valuable resource and I would like to find ways to access that knowledge and promote sharing the same.
I have included my "first efforts" below in the hope that it will encourage many of you to improve on those notes with some of your own that you value.
You can choose any topic area, this is just an experiment to get you all thinking about sharing that special area of knowledge you have that others might benefit from hearing about.
I will include my effort as part of a trilogy. "Before, during and after".
My first effort will focus on some thoughts on how I approach the "Before" aspect of a repair.

Before.
Any repair process starts with a close inspection of the complete movement prior to pulling apart. Even a clock that "just needs cleaning" can reveal some surprises. The rebuilding process should be just that, all the "innovations" of previous repairs will have been removed where possible. Any problems noted and repaired so the rebuilding process is an assembly and adjustment process performed on clean fingerprint free, swarf free and filings free parts. By close inspection when tearing down one can anticipate the required work and perform the repairs ready for a final cleaning prior to re-assembly. Discovering problems on re-assembly often means once again disassembling, carrying out the repair, re cleaning and starting to rebuild again.

Even if you think you "know the problem" a good pre-teardown inspection will reveal other matters that need attention prior to rebuilding.

Newer clocks often have worn bushings, after some time one gets familiar with where to look for expected problems on specific units. On a clock that has broken springs it is a good idea to look for broken teeth, bent arbors or pivots. Many antique clocks were so well made they survive just fine on infrequent cleaning and oiling but many clocks have stopped and been made "operational" again through "innovative adjustments". Those changes should be noted and plans made for their removal. Check the operation of any levers and actuating mechanisms, often overlooked since it's the wheels and train that are often seen as the problem. Bent or damaged levers, especially those between the plates can be a cause for extra work if undiscovered until after the rebuild.

Check that trains operate as they should, finger power should work most trains enough to check a chime or strike cycle or make an escape wheel go around one cycle. Even very close inspection when apart might not reveal a problem that is readily observed when all related parts are seen working together. The time to check those relationships is before tearing down. Its too late to guess what those relationships were when you are rebuilding.

When checking those relationships prior to teardown don't be fooled by what you see. The previous person may not have got it right either. You should always understand the mechanical operation being performed. Even if you have never seen such a movement before, it is only by understanding the operation that you will be able to successfully rebuild any movement. If the movement is not familiar to you take some time to look at the movement and watch its operation or try to cycle it through some operations and be sure you understand how it operates and the relationship of one train to the other(s). If an operation is not performing correctly be sure you understand why. On most clocks the "why" should be lack of lubrication or excessive wear. Look for signs of wear and add "finger power" to overcome poor lube and see if that overcomes the problem. On a worn part or area try moving the loose part back into its original position and see what changes.

The key to success is not that you are familiar with any particular movement, rather it is that you understand the mechanical operation being performed and that comes from careful observation of what you have in front of you. When you find a problem be sure it is a problem and not your lack of understanding the process. Often clocks are "changed" from the original configuration into "something else" based on the clock not performing as expected or not "looking like ones seen in the past". A recent example I came across was confusion over a silk suspension. The owner restrung the clock, mounted the pendulum and found the pendulum would only mount "crosswise" to the expected position. The remedy was to clip off the end of the pendulum and put a new bend on the end to make the pendulum orient the correct way. Sharp observers will note that this would make the clock out of regulation but what else is to be learned? This individual "restrung" the suspension as he thought it should be and then changed a manufactured part to fit changes of his doing.

It is rarely a good idea to change a manufactured part to "fit" or "work" with a part that you have changed, knowingly or otherwise, from the original. Slight "bending" is one thing but filing, cutting or "adding " is often performed due to a lack of understanding of the mechanics. It is poor practice to change a clock from its original configuration in the first place but be sure to understand that if you are making substantial changes to original parts you probably are doing something wrong. Never change an original part to make it fit your changes. Rework your changes to make them work correctly with the original parts.

A good understanding of the mechanism in front of you will aid in the rebuild. A good inspection prior to teardown will limit surprises when rebuilding and reduce "comebacks". This will also reduce the possibility of your own clock sitting on a shelf no longer running a few days after a repair..

Please feel free to comment and let me know if there is any potential value to such notes.

Ray Fanchamps


[This message has been edited by Ray Fanchamps (edited 12-19-2000).]

[Rod]

Ray,YES YES YES it is a great idea.......I would like to see more tips and ideas just as you have posted.

Rod

------------------
NAWCC # 0058915

[Gene Klodzen]

Ray,

Definitely a good idea, and thanks for your excellent repair suggestions.

Although I can't draw worth a darn, the most important thing I learned in my first clock repair class was to first examine the clock, as you advised,study it carefully from all sides, and make a sketch of it. In my case, it was a very crude sketch, but in doing so, it allowed me time to really examine the clock and know something of it before I disassembled it.

My point? You don't have to do a beautiful, detailed sketch, just something that you yourself can follow. Chances are, your sketches will improve along with your clock repair, you'll gain more confidence, and you'll have more fun, too.

Gene Klodzen

[Ray Fanchamps]

I have been sent another set of repair notes. They are included below. I will make a separate Board if there is both the interest in supplying notes and wanting to have such notes here.
Ray Fanchamps

The following notes were submitted by Barry Parker. Barry Parkers HomePage. (http://www.terrigal.net.au/~bparker)

My Notes on Preparing a 'Gunmetal' Watch Case for 'Blueing'
Many pocket watch collections include one or more blued steel cased watches, commonly referred to as, "gunmetals".
These cases are often found to house interesting movements such as repeaters, exposed escapements, eight day and moon phase calendars etc., and whilst the movements are most desirable, the cases are not as highly valued.
Almost all of these strong steel cases, which I have seen, were obviously "made to a price", mostly they were poorly finished originally and inevitably many of them have 'pitting' of the steel caused by rust. The problem was that I could not find anyone who was prepared to restore this type of case so I was forced to develop my own methods. I had approached a gunsmith who would do the 'blueing' if I gave him a prepared case which had to be polished to an almost mirror finish all over.
The old problem of 'Preservation' over 'Restoration' came up because, if you polish and re-blue, you invariably come up with a better than new appearance. So, if you wish to 'Preserve', rather than improve your case, then all you can do is to treat the case with a commercially available rust inhibitor and keep the surfaces lightly oiled to prevent further deterioration.
If you decide to try my method it would be difficult to duplicate the original maker's poor finish. The hand finishing and polishing which you or I would do would not have been economical for the original manufacturer, but I have no doubt that he would have approved of the end result.
Anyone who is prepared to spend several hours of their time, can use a file, sanding paper, metal polish and a buff can prepare a case for blueing. It is important to remember that blueing does not cover any surface faults. It simply changes the color of the steel. Blueing will NOT 'take' to any metal other than steel. Brass, nickel, copper or gold hinges or case fittings will not be affected by the blueing process. Any steel case which has been nickel or gold plated would have to be chemically stripped back to steel before it could be prepared for blueing.
Although there are exceptions, I have done one repeater case, for a Japanese customer, which had been gold plated and had some rust coming through on an outer lid and experimented by filing off all traces of the gold plating, on the outside of the case, polished the steel and after blueing the result was quite acceptable as the contrast of the colors complimented that particular watch.
The actual blueing process, ( the usual color obtained is more black than blue),involves de-greasing firstly then the use of temperature controlled, caustic chemicals and boiling in soluble oil, to harden the finish. You can forget about doing this at home, or in your workshop as even the air around the tanks becomes permeated with the caustic solution and any steel item nearby will go rusty, including any watch parts or tools that are touched by the air. It even burns my skin so I recommend that you leave it to the professionals.
A professional gunsmith will be able to arrange to have your prepared case blued, at a reasonable cost ( my guy charges $5.00), especially if you arrange to deliver it on the day that he does his regular jobs. Blueing should be done as soon as possible after final case preparation, to avoid surface rust forming on the unprotected finish. So it would be wise to have this organized before you start on your first job.
Assuming that you wish to try your hand at doing a case yourself, you will require some basic materials and tools. I use some good quality jeweler's files,#5 - #8, a few sheets of 3M "Freecut" sanding paper grades, 180,220,320,400,600 and 1200 wet & dry as well as #1 and #3/0 pivot polishing sticks, some fine grade "0000" steel wool, a good quality metal polish (Simichrome), a strip of soft balsa wood and access to a polishing mop.
THE PROCESS WHICH I USE:- After removing the movement from the case, remove the bow, setting pin (if any), repeater slides or buttons, glass and glass retaining rings (these are usually fairly easy to press out by hand from the back of the bezel and being made of brass, copper, gold or gold plated would not be affected in blueing, but it is difficult to get the steel bezel polished if you leave them on and you also risk scratching them). You could also try to remove the inner dust cover hinge pin as it is much easier to polish inside if you remove the dust cover lid. Remember, when looking down on a hinge, with the hinge being away from your body, the hinge pin (usually tapered) goes in from the right - out from the left.
If you choose to have any of the removed parts gold plated, including the winding crown, send them out to be done now so that they will be ready to re-fit when your case is finished.
Wash the case with liquid soap and a stiff brush under running water to remove any grime,grease or dirt BEFORE you do any work on it. Grease will clog sanding paper and dirt can scratch steel. Dry the case out and note any dents that will require attention.
TO REMOVE DENTS:-I use a block of lead covered with a sheet of clean paper (this is to prevent any lead particles from becoming imbedded in the pores of the steel). Hold the case lid on the block and ROLL a tea-spoon, or similar shaped object, whilst applying gentle pressure with your thumb, across the dented area. Examine the result and repeat the rolling with extra pressure if required. DON'T hit it with a hammer, this will stretch the metal and you will cause more problems than were there in the first place.
Peel off a wad of "0000" steel wool and go over the whole case, inside and out. This will remove some of the surface rust and, as you work, you will observe any areas which will require some special attention. I always like to start on the inside of the case first. The reason being that when working on the inside, the front or back may be scratched as you work on the inside and if you have already polished the outside then you have to do it all again.
If you find that the inside surfaces of the lids are in good order, YOU DON"T HAVE TO REMOVE ALL OF THE OLD BLUEING, just make it smooth by polishing out any light scratch marks. If polishing does not do the job, try some 1200 grade sanding paper then polish. Always use the lightest abrasive that will do the job.
Take special care when sanding NOT TO SAND ANY CASE LID CLOSING EDGES as this could affect the closing of the lids and would be a difficult problem to correct. You will have to be careful when filing out the inevitable knife slip marks around the case center and leave as much of the original edge as possible. The stepped ridges around the case center are difficult to polish and my method is to take a piece of the soft balsa wood strip (you were wondering about that, weren't you?) cut the strip to a point and charge it with polish and rub vigorously around the ridges, the hinge areas and also the inner lip of the case lids and any other hard to get at places. The soft balsa wood will not scratch and takes the form of whatever shape you are working on and seems to do a pretty good job on any type of metal case, particularly gold or silver.
Still on the inside, I use a motorized dental drill fitted with a jeweler's miniature polishing mop charged with Simichrome to get the best possible finish to all inside surfaces then I remove the circular patterns, left by the mop, by polishing by hand with a little polish on a fine cloth. You may have to do this again if it is necessary to 'pick up a pit' that may be found on the outside of a lid, but it is not usually too much trouble to do a small mark.
NOW TO THE OUTSIDE OF THE CASE:-I like to start on the outside of the front bezel first using the fine pivot polishing stick if the surface is not too rough. If this proves to be too rough, you then try the coarser pivot polishing stick. If this is still too slow, try one of the finer sandpapers, say 1200 grade (this will be a wet & dry paper, not free-cut).The aim is to use the finest grade of material that will leave the finest scratches first as you will still have to get down to the fine pivot polishing stick later,before polishing with the mop and polish. If you start off with coarse, you have to then progressively go to finer and finer, so try to pick the finest that will do the job.
You can see if you are doing it correctly as the blackened metal becomes silvery under the sanding and providing no small pits of black are showing up, then you are down to the steel. once you have done this with the fine pivot polishing stick, you then use the polish mop, clean up and see if there are any faults, repeat the steps until you have the almost mirror finish.
I then do the same process with the center band of the case. Whilst doing the band,you may notice some small areas where excess bronze brazing or silver or gold solder has been used in the original manufacture of the case. The usual places are around the stem, around the pin setting olive and the hinge areas, both inside and outside. You may carefully file off any excess down to the steel, providing that you maintain the integrity of the original joint. The new blueing will not 'take' to these areas and I have seen cases where it appears that these spots were simply painted with black touch ups, during or after manufacture.
NOW TO THE LID/S:- It is not easy to hold a case whilst working on it with the other hand and I have made up some circular wooden blocks about 1/2 inch thick which I can screw onto a bench post and the watch case center fits over the block and holds the case reasonably firmly. One day I will get around to making up an adjustable wooden holder that will do a better job. I have glued some slightly domed rubber on the top of the discs of wood and the purpose of this is to slightly lift the center of the case lid so that the filing or sanding does not leave a central 'hollow' (many cases seem to have this effect, probably caused in the original manufacture). It is much easier to make even sanding strokes if you can use both hands and the work is held firmly. Experience will teach you to select the correct method and grade of paper to now use in filing or sanding the outside lids.
It is worth remembering that the amount of metal to be removed, in order to achieve an almost mirror finish, is determined by the depth of the deepest pit in the metal. The metal must be sanded over the WHOLE surface with a rubbing block and NOT gouged out by "finger " rubbing. It is usually the lids which have the worst pitting, but as long as the pitting does not go all the way through the case, it may be able to be saved. (Welding up holes does NOT work, I have tried it). If you have a hole in the case, I can only suggest that you cut out a star or shield or some other pattern from a piece of gold or brass and silver solder it over the hole after polishing the rest of the lid, before blueing. If the lid is holed in many places, you may consider turning out the back, turn up a glass retaining ring and make it a display back. Alternatively, you could turn up a new back from a scrap case and insert it into the retaining ring that you make to suit.
THE LAST PIT:- There is always one last pit to remove and if you feel that it is too deep, you may consider pressing the back of the pit up to where it can be sanded out.
To locate the exact point to press, I use a pair of outside calipers and place one point on the pit and close the caliper on the lid, I can then mark the exact point with a pencil and then place the lid on the lead block with the paper over it, and using a small, domed ended, brass punch, I gently roll the ball of the punch over the point. This can be a little tricky as the metal may be very thin at this point, so you have to be patient and try sanding each time that you apply a little pressure to the pit. Repeat the process until you get it right. Once you have done the final polish, clean the case thoroughly and dry it well. I clean mine in clock cleaning fluid ultrasonically then rinse in white spirits, wash in running water, rinse again in methylated spirits (which mixes with water and picks up any water molecules) and then blow dry with a hair dryer.
There may be many other methods by which similar results may be achieved, this is only my method. I publish this article for general information only and accept no responsibility for any loss or damage caused by following these suggestions.
These pictures, shown below, are of an originally gunmetal finished, steel case which had been gold plated over a pitted surface in an ill considered effort to make it look better. Frankly, it looked dreadful as the gold plating had apparently been done without any surface preparation whatsoever.
To completely strip off all of the gold plating from all areas and get back to bare steel all over would have been a tedious and costly job, so the owner asked me to prepare the surfaces as shown for blueing and leave the inside of the lids and case center gold plated. As previously mentioned, the blueing process does not 'take' to gold and this was the final result achieved. The owner was very pleased with the contrasting effect achieved.
http://www.terrigal.net.au/~bparker/auction/quarterrep3.jpg
http://www.terrigal.net.au/~bparker/auction/quarterrep4.jpg
http://www.terrigal.net.au/~bparker/auction/quarterrep1.jpg
http://www.terrigal.net.au/~bparker/auction/quarterrep2.jpg



[This message has been edited by Ray Fanchamps (edited 12-24-2000).]

[Larry Jones 98326]

Barry, Ray, and others.

I applaud your willingness to spend the time to put all this in print. I'm a mediocre repairman at best, so the best I can do is toss out a obscure tip now and then.

I do think a repair notes board that also addresses specific repair questions would be a good idea - one that covers both watches and clocks, or separate, I don't know......

Larry

[doug sinclair]

As a result of a thread on the watch message board regarding oversized balance staffs for damaged balance wheels, I have given some thought to contributing to the message board on the subject of truing bi-metallic, temperature compensating balance wheels. This is a topic that is a bugbear for some collectors who like to do as much of their own work as possible. I am not certain if severely damaged balnce wheels can ever be made to be true, so this applies mostly to routine truing of balance wheels. I am assuming that anyone who might be interested enough to read this has a proper truing caliper and its attendant adjusting tool. It also helps to have some scrap balance wheels around to practice on.

1./ Some truing calipers are equipped for truing CONICAL pivots (as in cheap watch) balance wheels, as well as CONCAVE pivots. Do Not get the two mixed up. If you put your Howard balance wheel into the wrong side of the caliper and tighten 'er down, you can do a number on the pivots. Be certain to use the correct side!

2./ Make certain that the staff is tight in the wheel. You'll never true it if it is loose. This can be done by putting the wheel into your caliper, tightening the caliper, and turning the wheel while watching the staff. Truing should be done with the hairspring OFF.

3./ Once you are satisfied that the staff is tight, leave the wheel in the caliper. At this point it should be mentioned that any adjusting operation on the wheel should be done with the caliper TIGHT on the staff so that the concave pivot shoulder bears the strain, and NOT the pivot!

4./ Bring the index finger over so that it is close to the wheel with the tip pointing at the rim of the wheel and tighten the lock nut. Adjust the index so that the tip only touches in one place as you turn the wheel.

5./ The first thing you will want to do is to adjust the wheel so that the rim at the two opposing BALANCE arms are equidistant to the index. This is regardless of where else the wheel might be out of truth. If you don't take this important first step, it will be a difficult job to acomplish the truing of your wheel.

6./ Once you are satisfied that the rim at the arms is properly adjusted and the rim at the arms is exactly equidistant to the index on both ends of the arms, take note of the FREE ENDS of the arms and whether they appear to be out of alignment with the rim at the arms where you know the wheel is close to truth. Adjust the free ends one way or the other until they line up with the rim at the arms.

7./ At this point you should be able to bring the wheel to truth at the middle of each rim section by giving a slight twist to the balance arms with the adjusting tool(in the correct direction) near the outer ends of the arms.

8,/ Loosen the caliper a bit, spin the wheel and watch to see how close you came. If you aren't satisfied, tighten the caliper and repeat all of the steps above until you are happy with the wheel.

Some balance wheels are very tough and springy, while others are exremely soft. These can be tougher to true, Some wheels are tempered just right and adjust easily. Judgement must be used in applying any force to the rim during adjusting. The best way to get a feel for the malleability of your wheel is to spin it after each ajustment to see whether you have affected any correction with the force used. If you have over-corrected, the wheel is likey soft. If you have under-corrected, it likely is springy.

Happy truing!

Regards,
Doug S.

P. S. If you have a method that works for you that doesn't agree with the above, please post it and let the readers decide for themselves which way they want to do it. I don't know whether Fried's or De Carle's method is like mine or not, but mine works for me.


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[This message has been edited by Ray Fanchamps (edited 12-27-2000).]

[Preston Goering]

I am just getting started so I really think the idea of a separate repair board is great. I think one for clocks and one for watches. Even as a person becomes an expert, there is always something new to learn. As it is, I don't know for sure where to post my questions about repair--I posted one on the clock message board. I wonder if it may be helpful to begin a "Repair Business" message board, too. I also submitted a question about that to the clock board, unsure of where it would best be posted. I look forward to learning from other NAWCC members.

------------------
Preston D. Goering
The Clock Works

[MShaw]

Just a short idea from a new repairer.
I recently did a Waterbury kitchen clock with brass plated steel plates.

The factory bushing on the escape arbor was worn nearly to the steel and could not be fixed with a bushing in a bushing.

The horror is that the arbor bores are not centered in the bushings!! and cannot be replaced with a concentric bushing.

Not having a depthing tool precluded the normal solution.

My solution was to place a length of trundle pin wire the same size as the pivot thru both plates and hold it at the "good" end of the wear slot. With the depth rod of a vernier I accurately measured from the top and side of the plate to the wire.

The bushing was replaced with a blank plug. The measured dimensions plus half the pivot diameter were used to lay out the proper location for drilling the new pivot.

It worked for me.

------------------
Malkin E Shaw

[Gordon Andersen]

Hello Ray,
I think that your idea of a "repair tip" message board is great. I think that a board for watches, a board for clocks and also a board for case restoration would be great.
Keep up the good work.
Gordon Andersen
NAWCC 37104

[Ray Fanchamps]

I was in my workshop last night with an unusual 1/2 hour between activities. I found an interesting "quicky" to test as a repair notes exercise.
SUBJECT.
Restoration of an previous poor repair. Presented as a way to improve upon an existing repair using simple skills and hand tools.
Often clocks will carry the scars of previous encounters with a repairperson. Sometime I leave them there and sometimes they are removed. This is an example that I took care of as an experiment just to demonstrate how one can quickly do a
decent repair in about the same time as it takes to scab something together.

This image shows a wheel from the strike train of an 1830's English
30 hour movement.
http://www.clocknut.com/nawcc/e3rd2.jpg
It is a typical problem on these movements. Someone forced the strike mechanism to operate with finger power and it pops the tooth sitting over the stopworks.
The original repair was a scab of brass on the side of the wheel (in this case pinned and soldered)
shaped to a loose tooth profile.
This is a common repair problem, a good repair takes only a few minutes longer and
takes the same simple skills, sawing and filing.
The tools required would be basic hand tools including jewelers saw, triangular and flat files and soldering iron etc.
Note in this particular case the wheel has been soldered and pinned,usually it is just soldered. This means there is a hole in the
side of the wheel, this will affect this particular repair only in terms of how large I make the dovetail cut to clear the hole area.
http://www.clocknut.com/nawcc/e3rd1.jpg
The first step is to drill out the pin body to weaken it.
Second, unsolder the scab and pull it off. Because this was also pinned on there is a large hole in the side of the wheel.
When the scab is pulled off you are now at the normal start point of the repair of a broken tooth.
Some repairers just cut or file a slot and then place a sliver of brass in position and solder. I dovetail teeth into place, this means cutting a small dovetail like wedge out of the wheel. A jewelers saw cuts the
basic outline and then use a triangular file to shape true.
Here is a larger than normal dovetail, the pre-existing hole means my dovetail slot will be larger than normal.

http://www.clocknut.com/nawcc/e3rd4.jpg
I like to use replacement tooth material that is thicker than the wheel being repaired (parts movement plates, other brass parts are
scavenged). Shape the material to fit the slot cut, it takes a good
deal of practice to make a perfect match but you can cheat a little. File a little at a time as you get closer to fitting. Once the wedge starts to feel and look like it will soon fit I try to tap it in place. I want a good tight fit.
Once the wedge is fitted I place the wheel on a solid surface and tap the wedge sidewall with a small hammer (remember the wedge was thicker than the wheel) and this
expands the wedge into the precut dovetail.
http://www.clocknut.com/nawcc/e3rd5.jpg
You can see the outline of the dovetail and the roughed out tooth.
I would rather not use solder at all but I imagine changing temperatures and stresses might dislodge a tooth held only by peaning. (not to be confused with prick punching)
Solder has no structural strength, more is not better. You are looking to lock the wedge in place through light tapping on the wedge sidewall. Solder is just extra security.
Soldering takes practice. The two main problems one sees are
(1.)Cold soldering, where the solder is gloped on to a part not hot enough to get the solder to flow where it should have. Remember, heat up the part not the solder.

(2.) Rusted parts due to not cleaning
and neutralizing the flux. Remember, clean up flux with a water/baking soda mix.

Once you have the part soldered in place you can go for final shaping of the tooth. If you lay a file one the sidewall of the wheel
you can feel the high spot of the thicker wedge. Find the high spot and carefully file until the file rests flat on the sidewall, both sides. This action will also hide the dovetail marks if you have done a good fitting job.
If you roll the wheel on a flat surface you will feel the high spot of a long tooth, very carefully remove a little stock at a time to reduce the high spot. Once the high spot is hardly noticeable file about a 45 degree angle on the tip of both faces of the tooth and then round off the tip to blend in the angles. The width of the tooth can be thinned by filing if you have a thin enough file to fit between the teeth or use the jewelers saw to "shave" down the side of the tooth. Eyeball the work, try not to get the tooth too thin.
With a little patience and care and you will be able to hand shape a
tooth profile good enough for this 1830 movement.
All done in about the same time it took the original repairman to scab a repair.

http://www.clocknut.com/nawcc/e3rd6.jpg

This is not intended as a perfect or professional repair, just an alternate way to make a much better, cleaner repair , easily performed by the novice with hand tools.
The use of a drill /drill press would help in dressing up the wheel after repair, a lathe would be better yet but as I noted this was intended to be a simple process for anyone to handle.
These repair notes also are part of an attempt to encourage and promote the development of simple repair notes that many of us could generate and others could use to aid in their enjoyment of their hobby.
Suggestions and improvements most welcome.

Ray Fanchamps.



[This message has been edited by Ray Fanchamps (edited 06-02-2001).]