To Clean or not to clean a barrel

Posted: Sat Jul 09, 2011 4:04 pm     Post subject: To Clean or not to clean a barrel

Folks, 13 years ago I started to restore a old german wall clock. The restoration of the box was done and I just started working on the movement when I decided to take up on a offer and moved to a different continent. This is what the movement look like before I took it apart back then. (Still a 35mm picture)



A week ago I finally decided that now is the time so I unpack the box and started looking in to this again. Back then I got it fairlyy clean except for the inside of the barrels - just because I did not have the tools back then neither do I have it now.

Now my question. What do I risk if I don't take the barrels apart and clean it? To me the only risk is rust resulting in a risk of a broken spring (I sprayed some oil it back then for that purpose)


My second question related.

Based on the pictures I took back then I have figured out pretty much where every part goes. However, as a typical noob I do have difficulty to line all the pivots and holes up in order to put the other endplate back in position. What is the trick here - is there a good reference that anyone could recommend to provide me with some guidance in this regard?

This is what the parts look like after 13 years of storage.

Posted: Sat Jul 09, 2011 8:47 pm     Post subject:

A good book is Practical Clock Repairing. by DeCarle

Posted: Sun Jul 10, 2011 12:14 am     Post subject:

Being a repairman, my immediate reaction is you don't want to put dirty barrels back into a clean clock! That being said, I can understand why you are hesitant to tear into a couple of mainspring barrels to get them apart for cleaning without the proper tools. That goes against many of the safety rules and just plain common sense for dealing with a fairly heavy spring wound under a good amount of tension inside a brass container.

Apart from suggesting something that is done in the shop occasionally, I would advise you to seek out a clock repairman and try to get them to break down your barrels and springs for you, clean them in an ultrasonic cleaner and reassemble them again. Whatever they charge, you will be money ahead of trying to do this without proper tools, guidance, or safety gear and you could do some major damage to your body and other things if you lose control of that spring half way through the "extraction"!

Good luck with the project and I admire your "sticktoitiveness" to want to finish the job after 13 years! There are so many who would simply forget the whole thing and throw a perfectly good old clock in with the garbage.

Posted: Sun Jul 10, 2011 1:06 am     Post subject:

to put the clock together I would fasten back the posts that separate the plates to the bottom plate. Then put the top plate in place, and align the gear shafts with the top plate. Eventually it will all go together.

As the clockguy said get the mainsprings cleaned and oiled.

Posted: Mon Aug 01, 2011 8:24 am     Post subject:

There is a tool for hooking the arbors into their respective bearings, one at a time. I have seen pictures of them and it looks to be not much more than a length of bar, flattened out at the end. The flat bit has a hook shape cut into it. Easy to make I would think. (I hope so as I have got to make one soon.) If you start by putting all the wheels in their correct place in the front plate, then locate the bottom two posts of the back plate into position you should be able to gently ease the arbours into their respective holes by using the tool to hook the arbors into place working from the bottom upwards.

Note. I am a novice at this so my advice is taken from books, observation and logic. There are many more, far more experienced than me, on this forum so if I am wrong they will, I am sure, point it out to you.

Best of luck.

Alan

Posted: Fri Aug 05, 2011 3:35 pm     Post subject:

Thank you all who have responded. BigAl, yes, I have found the trick is to work from the bottom up. The tool that you described would certainly be a big help. I have to disassemble it again to do the final polishing and buffing, so I will make myself a similar tool for the final assembly - this time with cotton gloves.

Since I opened this thread I have listened to the advice and located a local guy who runs a repair shop in his basement, and he did the cleaning and greasing of the barrels for me. Everything run so nicely now.

My follow up question. When it comes to lubricating the clock. There is no doubt in my mind that when lubricating the small pivots one should use a proper clock lubricant. However, given the force on the barrels and say the first wheel driven by the barrel, (which also has a thicker pivot). Should I not consider to use something like a white grease to lubricate those friction parts. I am concerned that the clock oil may be too thin for the forces present at those interfaces.

Posted: Fri Aug 05, 2011 5:32 pm     Post subject:

Areas or points of greater frictional contact is one of a few reasons why Klockit recently added the following product (which has tested quite successfully for us so far):

http://www.klockit.com/products/dept-360__sku-99140.html

That being said, please check back for further responses as well. It is always good to have a second opinion, especially when it may involve the personal preferences of more experienced clock repairers.

Posted: Fri Aug 05, 2011 8:43 pm     Post subject:

Thank you Chris - that surely looks like some good oil. Definitely something to consider.

Posted: Fri Aug 05, 2011 10:06 pm     Post subject:

4wheel,

Consider this, the spring barrels do have the most power as it is coming directly off of the mainsprings that power the clock chimes and time drive. But they also work the least (turn with the least number of revolutions) in any given period of time. I can't argue the sense of thinking that thin oil on those heavy pinions may not last long but the mainspring barrels don't turn that many times compared to the top wheels on each drive train and the thin oil that is used for lubricating those wheels lasts for years.

Posted: Sat Aug 06, 2011 1:03 pm     Post subject:

Hi Clockguy, yes, I agree, it does turn slower, my concern is however not if it will last but more about will it ensure that there is no metal to metal friction due to the higher forces in these areas. I probably just know enough to be dangerous but my gut feel is based in the fact that the thickest lubricant in a car is found where the forces are the highest. For that reason the gearbox (or transmission - depending on which side of the big pond you are) oil is traditionally thicker than engine oil.

Since posting my question I have read on the www.nawcc.org forum that some (not all) posters recommends 5 "weight" on the small pivots and 85 "weight" on the barrels. If the "weight" represents the same viscosity as the SAE standards for car oils, then 85 is pretty much the same thickness as car gearbox oil. However, if experienced clock repair folks that have seen clocks 5 or ten years after they have serviced them, say 5 is fine on the barrels then it saves me buying a second type of oil.

PS In my research about oils I have noted that Hermle now lubricates all new mechanisms with the oil recommended by Chris above, so it must be good stuff.

Posted: Sat Aug 06, 2011 4:58 pm     Post subject:

"my concern is however not if it will last but more about will it ensure that there is no metal to metal friction due to the higher forces in these areas."


I am not sure I follow your line of reasoning as you will always have some amount of friction when two objects rub against each other no matter what the speed nor what type of lubricant, if any, is used. I agree that there are strong forces being transmitted through the drive train of most vehicles to the driving wheels but I think the heavier lubricants are used because of the much higher speeds attained in normal operation as much as the fact that there is more or less "power" in that area. Higher speed equates to more friction which, in turn causes higher heat ranges and could contribute to eventual damage to the gear train in a transmission. Thicker viscosity lubricants will stay "stickier", allow less heat to be generated as it lowers the friction coefficient, and help to dissipate that heat under normal operation of these high speed parts.

If we equate "forces" with "power", I suspect that there is more "power" on the main crankshaft, rings, and bearings of the "power generator", the engine, than in the gear box of the power train but we use quite light weight lubricants in the engine sump around these areas to keep them operating efficiently compared to the heavy gear oil in the transmission. Even with the heavier lubricants, there is still a need on some high speed racing machines to further cool the transmission oil with an oil cooler which helps to dissipate the heat even faster.

I use a heavier weight lubricant on the mainsprings themselves after proper cleaning and inspection. That isn't to cut down on the damage from "power" or the heat from friction so much as it is to allow the coils of the mainspring to slide within themselves as the spring unwinds. Not only is it wound tightly against itself but it suffers from an element of compression from one coil to the next and the coefficient of friction on a dry spring is much higher than it is on a lubricated one. The compression of the coils against themselves further complicates the issue because they have a tendency to want to squeeze the lubricant out from between the coils if it isn't heavy enough to resist that "squeezing" pressure. Thus, the viscosity of that heavier lubricant resists the compression forces trying to force it out of the coils of spring and allows the spring to slide as it unwinds itself during the clock operation instead of "jumping" as the compression forces are relieved from one coil surface to another. If you have heard an audible pop or snap as the chimes are ringing or the hour is being struck or the clock is simply operating between chime sequences, you will know what I am talking about. Those sounds are caused by dry surfaces of the mainspring suddenly shifting as the spring unwinds far enough to ease up on the frictional forces holding the coils from sliding freely.

I hope this long winded dissertation made sense to you.

Posted: Sat Aug 06, 2011 6:49 pm     Post subject: Friction Clutch mechanism

Thank you again Clockguy, it makes perfect sense. I appreciate your effort in taking the time to write this explanation. I am feeling more comfortable now using 5.

When I took this clock apart 13 years ago I made some cryptic notes and took a few pictures before disassemble which have helped me (surprisingly) very much up to now. There is however one piece where I am not 100% certain about, and that is what I call the "clutch" mechanism (for the lack of a better term). The only part that fits here is slightly bended pin that rubs on the slightly concave centre part of the five blade pressure plate. There is absolutely no way that I will be able to get a washer (which I don’t have) in there too. It just looks so crude. Can anyone tell me if you have seen a similar setup before?

Posted: Sat Aug 06, 2011 9:06 pm     Post subject:

That pin arrangement , as clockguy will also tell you, is a common way these clocks were made. However the pin and washer suffers a bit of wear and the washer strength suffers a bit over the years. This can lead to the friction tightness becoming a bit loose or not quite as tight as it should be.

Similar movements were made with a bent piece of iron in a 's' shape in place of the pin. This type in my opinion is better as sometimes the pin comes out if the washer tension becomes too weak. The recess/hollow that the pin sits in just about keeps the pin in place.

Posted: Sun Aug 07, 2011 12:37 pm     Post subject:

Thank you clockfxr, Good to know that I was on the right track. I will watch out for the symptoms you are describing. For now the fit is still pretty tight.

Posted: Mon Aug 22, 2011 12:17 am     Post subject: The clock mechanism is ticking

I am glad to report that I assembled the clock and it is ticking again after what must have been more than 50 years as far as I could gather. Even the strike mechanism is working. I had to adjust the tic - toc duty cycle to get it as close as possible to even and I am pretty happy with it. It has been running for more than a day now.

However, when trying to fit the hands I found that I am missing what must have been the only part that I have lost, namely what appears to be a small bush interface between the square pin where the minute hand fits (i.e. over at the other end of the part in the picture above) and the round hole of the minute hand. The shaft is about 2mm square and the hole in the minute hand is about 3.6mm in diameter. (So I am literally sitting with a square peg in a round hole problem.)

One solution that I considered was to order a new set of hands of similar design where the minute hand has slot in stead of a hole. The second was to try and manufacture such a small part - making a square hole will be the problem here and the third was to see if I could find such a part.

Any suggestions from the more experienced folks?

Posted: Mon Aug 22, 2011 2:39 am     Post subject:

It sounds to me like you have somehow lost the insert for the minute hand which would have had a square hole in it to fit over the center shaft. The insert is there to fine tune the minute hand when it isn't quite lined up with the hour or half hour on the chime sequence. It can be turned back and forth to align the minute hand to the "12" position whenever the clock strikes the hour. This insert, which normally will not simply "fall out", can be turned with a pair of pliers or straight line grippers to align the hand exactly with the "top o' the hour" and it is a tight enough fit within that 3mm hole in the minute hand so as not to allow the hand to flop around.

Posted: Mon Aug 22, 2011 5:02 pm     Post subject:

Yes Clockguy, that is exactly the piece that is missing. I have since found that the square hole in a #1 Robertson brass screw heat is very close to what I need. First job in years for the old unimat SL1000 lathe. For now I am keeping my fingers crossed that there will be enough space between the chuck and the screw head for the cutting tool. Will keep you posted.

Posted: Thu Aug 25, 2011 11:23 pm     Post subject:

The Robertson screw head was a good start. There is still a little too much play to my liking but I will have to pick up a different lathe bit before the next attempt.

Here is a picture of the latest status also showing the home made adjustable pendulum.

Posted: Thu Aug 25, 2011 11:39 pm     Post subject: Chime rods

The above clock used to have 3 steel chime rods of which the longest one broke at the neck. The strike mechanism has three hammers, two of which are mounted on the same pivot. The single hammer is striking the back most rod and the pair strikes the two rods closer to the front. I removed the rods back then and from memory (something I am not relying on lately) the longest was at the back and the two shorter ones at the front, meaning that the long rod will be hit by the single hammer and the two shorter ones in unison by the dual hammers.

I have found a supplier for similar steel rods and decided to replace all three, mainly because the tapered parts on the existing rods are not round - which I have read is not the ideal for a good sound.

I cannot find any "tuned" steel rods, only shorter tuned brass rods. Since it is only a striking clock (no tune) this may not be important, however, I would like it not to sound "off tune". Is the intent that steel rod should be tuned by the clock maker:?: What tool is used to cut the rod:?:

Posted: Fri Sep 02, 2011 11:17 pm     Post subject:

That's a great looking wall clock and a really nice restoration.
I'm working on a few myself. Its amazing how inexpensive you can get old clocks for that are not working but need only some cleaning and oiling mostly. I came across a few spring barrels that I simply could not fix and luckily, they were all numbered and I was able to order new replacements (they're expensive but with the cost of new mechanical movements, it still makes sense to replace them).