Pillar & Scroll Repair

[David Goodman]

If it were my clock I might decide to do it. If it were your clock you might do it. But if it is someone else's clock I would be sure to explain to the owner that it is a major change from the original of such nature likely frown on by "Cog Counters" (wooden clock collectors) for whom originality is of major importance.
And subsequent restoration likely more difficult than doing it properly now.
.

[wes cobb]

No! It would not be OK! You are about to butcher an historic clock. This will cut it's value in half.
Wes

[Lincolnhill]

Wes-

Could you please explain your thoughts more?

I understand that it is a drastic change from original, but do not understand why you feel this would effect its value by half if at all.

If a current bushing is worn beyond use and must be replaced, how does slipping a small brass bushing in the already enlarged hole permanently change the clock?

It is my understanding that a new wooden bushing is multiples larger in diameter than a brass one so if and when someone wanted to bring the clock back to origianl all signs of the brass bushing would be have to be eliminated to fit in a new wooden one. Subsequently noone would ever no they were present.

If I am off base please let me know.

I have not rebushed this clock yet, so no harm...no foul.

I am just looking for input from other members before I tackle this exceptional piece of history.

Michael

Edited to combine two posts.

[This message was edited by Phil Schilke on January 02, 2003 at 17:24.]

[Schlitzer]

:smile:Hello Michael. I have repaired a number of pillar & scroll movements that way with very satisfactory results, and I would be among the last to permanently harm a wooden movement. If you do it, use small thin brass bushins like KWM or Bergeon which are about 150mm thick. I use tapered reamers to set them into the wood from the inside of the plates, and they are so thin compared to the thickness of the plates that they are not visable when the movement is assembled. Make sure the hole for the bushing is a tad smaller than the bushing diameter so it will press in with a snug fit and not loosen. Bushings need not be extemely tight, just snug. I also use tapered reamers to enlarge the hole in the bushing so the pivot wire fits nicely. I do all of this by hand and don't use drills and/or bushing tools. Most of the time, only certain holes need bushings. Usually, the ones higher up in the train. I only bush those that certainly need it in order to run without the teeth binding. Most wooden movements will tolerate quite a bit of slop without problems. They certainly were not precision. If the wind arbors need bushing, I use thin brass tubing that is readily available from many hardware stores or hobby shopes. You'll have to cut it to a proper length, but I have had great results with it. I use this rather than clock bushings because it has very thin walls and will do a fine job without having to make a larger hole in the plate. Most of the time, however, I haven't had to bush the wind arbors. A few words about wooden bushings. What are they, and who in the world would use wooden bushings? Some of the original movements were bushed with ivory or bone, and some makers used large brass bushings, but I never have seen wooden bushings. Most of the original plates simply had holes drilled in them for the pivot wires. I think using some kind of wooden plug would require a much larger hole in the plate and would be more visable. I think using wood bushings is a bad idea and bad repair. I hope this helps. (I have two such movements to do right now!)

[LaBounty]

Hi Michael-

I've restored quite a few wooden works movements and have seen everything from cotter-pin shaped steel sleeves to square pieces of ivory used for bushings. I think your biggest problem in using brass bushings is how to keep them in a wooden plate. You mentioned large temperature swings as one reason for using brass bushings. Won't they fall out if the wood shrinks? What will happen to the oil you will need to put in there? Won't it get absorbed by the surrounding wood plate or by the wood shaft? Wood works aren't supposed to be oiled (except in a couple of specific places).

My suggestion would be to make your bushings out of 1/4 in. oak dowel, cut to length, center drill your holes, glue your bushings in place, then size your holes to be a little extra sloppy to account for temp changes. When you clean your plates with a linseed oil and turpentine mixture, the oak bushings will conveniently take on a color close to that of the plates. The wooden bushings can still be taken out if they need to be replaced in the future and are much more in character than the brass would be.

If you are concerned about making such a large hole, use a smaller dowel.

I think you should be commended for wanting to do the best for the clock and working to educate yourself to that end. Keep up the good work! (but don't use the brass bushings in a wooden works)

David.

[Schlitzer]

:smile:Hello again, Michael. Just a couple of more comments. First of all, if you want a poor repair that is impossible to correct, just try drilling out the holes and using wooden dowel. The thought makes me cringe. Second and finally, I haven't had a bit of trouble with the bushings loosening. Those old plates are stable after all these years, and you don't have to worry about shrinkage, expansion, or warpage. You hve to make sure that the bushing is snug in the wood, but the friction on the bushing is so small that they easily stay put. Also, there is no end load to push them back out. I press them in by hand, and you only have to make the original hole a small amount bigger in order to press the bushing in flush with the inside surface of the plate. Try taking a junk plate and practice. You will see that it is easy to do. Good luck.

[LaBounty]

Hey Schlitzer-

I'm at a loss as to why using a hard wood dowel is an improper restoration technique for a wood plate movement, but I guess you have your reasons.

Also, You haven't addressed the problem with the oils being absorbed...

I'm not too old to learn new things!

David.

[Schlitzer]

:smile:Hello Phil and Michael, Repair of wooden movements is somewhat dear to me since I collect them and have seen many incompetent repairs. Phil, the oblong hole in the plate from appreciable wear is very obvious. It is easy to apply some side pressure to the reamer when rounding the hole for the bushing and compensate for the elongation. These brass bushings are small, and not much work is required with the reamer. I do this all by hand using reamers in pin vises.

The bearing surface is only a small part of the thickness of the plate. If you look at both sides of a wooden plate, you'll see that the actual bearing surface is only about 1/3 or less of the plate thickness. A brass bushing of that thickness or less works perfect. I lubricate the pivot with a tiny amount of mineral oil. It lubes the bearing and doesn't harm the wood.

[Bob Reichel]

Don Bruno can supply satisfactory wood bushing. All this talk of other materials makes me cringe. All dedicated restorers aim is to return the unit to as close to original as possible. Using wood bushings would be what the original mechanic would do. Also plugging the hole with wood and re=drilling should work. Don can be reached at:
<don.bruno@rcn.com>

Bob Reichel

Edited to make the email address live.

[This message was edited by Phil Schilke on January 03, 2003 at 15:18.]

[jimkatzin]

Lincolnhill,

I would strongly advise against using brass bushings. The last two wooden works that I repaired had brass bushings in them and they were a mess! In the first place, the pivots are not hardened in these clocks, so they score much more easily in the brass bushings then would be the case in a better made clock. I don't suppose you've ever repivoted one of these, but let me assure you, it is no picnic. The reason you don't use dowel is that dowel has the grain going lengthwise and will not wear as well as the original bearing surfaces. I use a 1/4" plug cutter available at any hardware store and cut my own plugs out of cherry. I find that the fine grain of cherry is easier to work with than oak; it cuts much cleaner. To locate the center of the bushing, I use a quarter inch transfer punch and then drill out the bushing to suit the pivot. If you use brass, then the owner will have to have the clock serviced on a regular basis. Wooden bushings can last for years with no attention at all. Also, depending on what sort of brass bushings you use or make, if the oil sink doesn't keep the oil contained around the pivot, the wooden plates and arbors will surely suck it dry. Using wooden bushings does not take any longer than using brass, so why would you even consider brass?

Jim

[LaBounty]

Hey Jim-

I hadn't considered using a plug cutter to make bushings. That is a good idea and I may look into it. Oak dowel rod is easy to come by and if you align the grain with the direction of wear I would think it would work just as well and last just as long. And since most plates are made of quarter-sawed oak it would be in keeping with the already mentioned aim of returning it to as original as possible. The only problem I've found with dowel rod is getting a true hole through it. The grain has a tendency to pull the drill bit off center and I usually end up with one bad one for every three good ones. Your plug method would solve that problem I bet.

Thanks for sharing your technique!

David.

[Andy Dervan]

Michael,

I hope enough folks have convinced not to use
brass bushing. If you check the Bulletin index,
I am sure there are several areas about using
a wooden plug and drilling out new hole.

A gentleman named "Barlow" published a short book
on "Repair of Wooden Movements" in 1979. You
probably could borrow a copy from NAWCC library.

Andy Dervan

[Jeremy Woodoff]

I think the idea of using thin brass bushings inserted from the inside of the plates and invisible or almost invisible from the outside of the plates is good as far as maintaining the original material and appearance of the plates. But on balance the points about excess wear of the soft iron pivots in the brass bushings and need for regular lubrication win out. I would go with the smallest diameter wood plugs, grained and colored to match the plates as closely as possible. It is interesting, though, that Black Forest wood plate clocks typically have brass bushings as an original feature.

[Schlitzer]

:smile:I have to make a couple of more comments in support of using brass if you want a good repair that doesn't harm the movement. First of all, many of the original movements were and are bushed with brass. Jeromes and Darrow made many such movements, both 30 hour and 8 day, and many are still around. However, their brass bushings are about 1/2 inch in diameter and are set about 1/8 inch into the plates and flush with the inside surface. I'm not suggesting using such bushings in other wooden movements, but I don't think lubrication or wear of the pivots is any problem at all with brass bushings. I'm not sure who else used brass or bone or ivory bushings. Perhaps the great Bulletin supplements and articles by A. Bruce Burns, Snowden Taylor, Bill Wadleigh and Ward Francillon contain that information. I don't remember.

The main two reasons I use brass bushings is that first they are only a little larger in diameter than the pivots themselves. Hence, you don't need to damage the plates by drilling out the pivot holes. Second, they can be easily removed and replaced with wood or brass if needed without any damage to the plates.

Certainly, there is nothing wrong with using wooden bushings, if it is COMPETENTLY done. This means using the proper wood, with the proper grain direction, and using very small diameter plugs. They don't need to be 1/4 inch in diameter, or even 1/8 inch, to bush most pivots. Drilling the plates with such large diameters permanently damages them. I've seen repairs using 1/4 inch plugs, and I think the damage is too great. The problem is that many attempt repair thinking that they must use wood without thinking about the permanent damage that results.

I also would use wooden bushings if I had some small enough. Yes, they can be made, and if you can, by all means, make them. I don't know what sizes Don Bruno can supply, but if you can buy them, then, by all means, buy them. Don is probably the best wooden movement man around, after his father George, that is. I have never asked either of them their thoughts on bushing.

The real issue here is how to bush a wooden movement without causing any harm. Using brass bushings as I do doesn't cause harm, easily undone, and works well. I will contact Don Bruno myself to see what he has available, and perhaps buy some to see what they are like.

[Lincolnhill]

Wow, I am thrilled by the number replies and multitude of ideas shared with them.

I would like to thank all the members who have shared their thoughts on wooden movement repair. This forum is one of the best benefits of being a member of (or having access to) the NAWCC.

For those of us who are younger (early 30's) and still have much to learn about the finer points of clock repair this is a fabulous service. What better way to increase our knowledge and skills than by listening to others share their experiences, and or mistakes, in a polite and civil (for the most part :smile:) manner.

Thank you again for your input. While I am still on the fence whether to choose wood or brass, I now have a better understanding of the pros and cons of each.

Michael

[jimkatzin]

I often get my quarter inch wood plugs from Don Bruno. As far as I know he never uses brass bushings unless they were originally used in the movement. As far as Hoadley's use of ivory (or bone more likely) for his bushings, it is generally understood that they were used more as a marketing gimmick than a true improvement in the performance of the clock. The same can be said for brass.