Restoring your vintage "ships" clock.

After repairing the detached mainspring on my clock I am restoring the case, after 6 years there were a few areas of corrosion starting to appear, and not being able to go sailing I thought I would fill in some time doing that and writing this post. 

A 3" 8 day clock, often more
suitable for small craft than a
6", Signed by Marpro but a
Smith's Calibre 51, 1960s?

Restoring or servicing the movement can be high risk for the layman, after retiring for the first time I got fed up with nothing to do and set up a business restoring and selling pocket watches, over about 7 years until I retired for a second time, I did over twelve hundred of them that paid for Sancerre and more. I also did marine clocks, they need different tools so I restricted myself to servicing and sorting the cases rather than mending them, but as people were not prepared to pay enough money to make marine clocks worthwhile I did not do many. I now have three full size ones and a smaller 3", two of them left over, two kept on purpose and you can probably guess which. I normally have one on the study / workshop wall and one on the boat. 

For anyone interested in pocket watches my blog of the time is still in existence here and includes pictures and descriptions of a lot of very interesting watches and some information on watch repairs and restoration, much of which is relevant to clocks (click on the faults and repairs tags) . There is also a story about what happened when I became watchmaker to Wonder Women, there was a follow up for the second film with some mods required but I only wrote that up on the Facebook page now deleted,

With the above in mind I'll mainly be saying what not to do with the movement and give more positive guidance on the case and glass. 

First the warnings:

• 

  The motion work of a centre
  seconds clock, the inside is more
  complicated. If you do take one
  to pieces take photos at every
  stage to help you when putting it
  back together.

  Do not mess with the hairspring or balance unless you know what you are doing, in which case there is not much point in reading this post! For some reason people seem to think that they can pull or tweak them, I scrapped dozens of pocket watches after people had done that. Adjusting hairsprings and the escapement is a skilled business, damage it and fixing it will likely cost much more than the clock is worth, if it is possible.
• Don't mess with the mainspring, if you take it out of the barrel you won't get it back in without the right tools (and if you did manage it there would probably be big isochronism (*) problems due to twisting of the spring), putting a new one is easier as they come pre-wound ready to slide in, but don't bank on being able to do it, take it to someone who does it for a living.
• If taking the movement to pieces ensure it is full wound down before doing so or you will cause significant damage, to be sure put the key on the arbor, hold it and the movement steady and release the "click" (ratchet) and let the rest of the tension off. Like many operations on watches and clocks you could do with three hands doing this.
• Some more modern marine clocks are plated, abrasives may remove the brass.
• If removing the hands take care, the hour & seconds hands, and perhaps the minute hand are a friction fit, levering against the dial is liable to damage the dial. Ideally use a clock makers removable tool or at least use something to protect the dial. When replacing hands, especially the seconds hand do not push it too far on, that can cause friction and stop the clock or make it run short and / or keep bad time. Counter intuitively an escapement that is underpowered, perhaps due to excessive friction in the movement, often runs fast, this is because the balance develops a very shallow and therefore fast action.
• Repainted hands may look worse than worn but clean ones, the exception might be ones that have badly rusted, in that case remove the rust before making a decision, blueing or blacking (in oil) would often be preferable to paint. The exception is the big, usually red, seconds hand on a centre seconds clock, most I have come across have been in poor condition but come up well with red enamel, remove all rust before painting.
• Do not use clock oil on the escapement (The balance (requires it to be removed so not recommended), lever & escape wheel pivots plus the pallet jewels), a platform escapement is about the same size as a pocket watch escapement and needs a light watch oil, a thicker one will likely gum it up. A light clock oil or a heavier watch oil will be OK on the movement pivots.
• On no account spray a movement with WD40 or similar, I have seen that a number of times on pocket watches. It may work in the short term but it will soon cause problems and the residue is difficult to get off unless you have an ultrasonic cleaner. If you have one that it has been done to it will need taking to pieces (except the mainspring barrel) and everything, including the hair spring, needs to be cleaned with a suitable solvent, preferably in an ultrasonic cleaner.
• Do not over oil anything, it will cause as many problems, if not more, than under oiling. Only a small drop is required on pivots. and perhaps a couple of drops of heavier oil into the barrel for the spring but it the clock is running OK leave the mainspring alone.
• If someone tells you a non running clock is over wound don't listen to them, they don't know what they are talking about. If you over wind a watch or clock the spring, or possibly the "click", breaks and its pretty obviously not wound.
• Don't try and clean the dial unless you are sure it is cleanable, many have ink printed numbers etc., often on paper or paint and one can run into the other, any attempt to clean one of these is likely to be disastrous and will require it to be replaced, also names may be transfer printed and come off with the slightest touch. I bought in a nice Kelvin Hughes clock where someone had tried to clean the dial, it looks good with the modern replacement dial but it would probably looked better with a slightly mucky original, just harder to sell. Replacement pre printed dials are readily available for £4-£5 but you will have to cut out the holes for everything apart from the centre one.

My Kelvin Hughes 6" clock, the replacement dial I fitted makes it
nice and easy to read but an original would probably look better
if in reasonable condition. The 8 day centre seconds movement
was probably Coventry made for Hughes in the 1950s. The
Barometer is by Broadhurst Clarkson from the inter war years.

Another centre seconds marine clock, this a 7" in a painted steel
and brass case. It had a replacement dial when I acquired it, the
"Astral" movement is from the Williamson factory in Coventry, part
of Smiths from 1934. Date unknown, but probably early 20th century,
Williamson also made a lot of pocket watches after acquiring
the business of CH Errington in 1895 and started to use the name
Astral, on pocket watches in about 1907.

My 90 year old 6" dial - crazed, dirty but usable with more character
than a new plastic dial. Unlike many, the movement runs for 15 days
rather than 8, time keeping suffers on the 15th day (it is in any case
normal to wind every 2 weeks or more frequently, the extra day is a
"spare") and probably briefly when fully wound due to poor isochronism(*)
 in an old clock, a new mainspring would help that but it is not worth the
effort, unless the current spring detaches again.  

The clock is from the mid 1930's. The escapement is signed by  "The All
British Escapement Company" that started production in 1931/2  and it is
before 1939 / 40 as it is signed by a chandler in Rotterdam and by post
war the escapement company had changed it's name.

Mercer signed as maker, they were and are, a premier maker of marine
chronometers, but they almost certainly bought this movement in.

(*) Isochronism: In this context the ability of a clock to keep time independent of how close to fully wound it is, there are several ways of controlling it covered on my watch blog here.

Regulating the clock

I have the kit to do this electronically using a computer, without that you will need to run it for 24 hours (perhaps less for the first few runs), note the loss or gain, make an adjustment noting how much you moved it, if lucky there may be a scale. Run for the same length of time, note the error, adjust, note and repeat until it is acceptable. Make the first adjustment(s) fairly significant, if you are lucky it will change from running fast to slow or vice verse you can then estimate how much to move the adjuster back.

Ensure the clock it vertical whilst you do this, it the escapement has a positional error (keeping time differently in different positions), you will be wasting your time doing it face up. Positional errors are not a significant issue with a clock so unlike a watch they would not normally be adjusted for it as it takes time, even with analogue or digital timing machines. Wind it well before each run but try and stop just before it is fully wound, you don't want errors due to isochronism errors.

My Mercer after restoration but with an old main spring will be within a minute or perhaps two after 10 - 14 days, it sometime has a rough time on the bulkhead of Sancerre.

The platform escapement on my Mercer. There are two speed
adjustments, course / initial adjustment is made moving the small
leaver, right of the centre of the balance and fine adjustment using the
leaver going through the dial, set centrally when making the course
adjustment. Be very careful and ensure that you don't kink the hairspring,
possible if someone has messed with the curb pins so the spring does
not slide though them.

Visible centre bottom is a screw that adjusts the end float on the
seconds wheel, if too tight it will create too much friction and could
stop the movement or cause bad time keeping, if too slack time keeping
might be a bit variable. If very slack it could disconnect the escapement
with dire results for the mainspring and perhaps other parts, as the
movement unwinds at great speed. If you take the movement apart,
tighten this screw for minimal float before winding and only slacken
if necessary.

The Glass.

If it is mineral glass and in acceptable condition leave well alone, minor marks can be removed using CeriGlass or similar, you won't be able to properly clean / polish the inside of the bezel but taking it out is a risk. If it is plastic / acrylic it may come out easily which will make cleaning and lacquering easier. If very old plastic it may have turned yellow, in which case replace it.

I would advise not trying to replace with a mineral glass, they are supplied "rough edged", unless you are lucky smoothing that and shaping it to fit the average marine clock bezel can be a non trivial job.

New acrylic glasses are readily available and costs about £9, they are easy to fit and won't break if they come out, but they do scratch and scuff much more easily than glass. To fit, clean out the old glue, mastic or whatever from the bezel, a graver works well, but whatever you use be careful not to slip and scratch the bezel. Fit using a thick weak glue, a strong glue such as an epoxy may cause major problems when it needs replacing again (less of an issue with glass which should last years) and a thin glue may not work on the rough surface of the bezel. There are specialist glues that are UV activated requiring a UV lamp, but G-S Hypo was designed for the job, is cheap and easy to use, just follow the instructions and do not skimp on it.  

Cleaning a brass case.

Warning, this can be a long job! Consider removing the glass (see above) and the bezel from the case, both make life easier but is not essential.

Remove the movement, usually just four screws, and put in a safe place.

While I was about it, on this clock I replaced the long broken
off opening knob, the remains were drilled out and a piece of
brass rod press-fitted and glued in place.

Remove the old lacquer, this is best done with multiple applications of paint stripper, it will save a lot of rubbing. Wire wool will help get partially detached or softened lacquer off whilst rinsing the paint stripper off.

Warning: paint stripper and solvents could interact with the adhesive holding the glass in, so handle with care. Also check that they are OK with plastic, if not remove plastic glasses.

Now for the tedious bit, rubbing down. As ever it is a case of starting with a relatively course abrasive moving towards finer. A 240 grit is probably as course as you want to start with, wet and dry will work but I prefer the "Garryflex" flexible block I used on pocket watch cases, but be warned it sheds "grit" so do the work over an easily cleaned surface or paper.

Scratch pens.

For odd corners and areas of corrosion a fibreglass "scratch pen" will be a great help.

Wire wool is also useful in odd corners and is my final step in cleaning the case.

Now you need to think about the type of finished you prefer, if a "brushed" finish then keep on with wire wool, if smooth then switch to Brasso, I prefer the liquid over the wads. Jewellers rouge is an alternate but it is so messy I gave up on that years ago.

Ready for polishing.

Ready to degrease.

Now is a crucial step; degreasing. If this is not done properly the lacquer will not be fully effective and you will be doing it all again very shortly. Best is Acetone but others will do, perhaps white spirit or methylated spirit, the latter is often the cleaner of choice for lacquer brushes so should be a good alternate. Don't skimp or hurry this! From this point on wear clean gloves to handle the case until the last coat of lacquer has dried.

Done and back on the office wall until next
season. The lacquer not as smooth as I
would have wished due to the hot weather
- its 27C at 9 in the morning.
Contrary to what I wrote, this is a mineral
glass, I was lucky and one fitted this clock
with minimal work.  The barometer is a
relatively modern one by Schatz.

Now more decisions are required, what lacquer and what colour? I can't give comparative advice on the brand as I have only used Horolacq. I prefer clear lacquer for the light brass colour, also available are red and gold colours that may help in covering blemishes, some are so dark and red the case ends up looking more like copper than brass, your choice.

Some people recommend warming the case is an electric oven (which helps dry it) and applying lacquer whilst it is still warm as used to be required for some lacquers. I have not tried this and the instructions with the horological "cold" lacquer I use does not mention this option. As I have just found out, avoid very hot (30C) and humid weather, the finish is not as good.

Apply multiple coats of lacquer, I suggest at least four, salt air is a very hostile environment so the more the better to ensure there are no pin holes or thin areas. If damp gets in through one pin hole in the lacquer in time corrosion will spread under the good lacquer, pushing it off and increasing the rate of spread. 

As with varnish and paints more thin layers are generally better than fewer thick ones and make sure the previous coat is fully dry before overcoating, so it is likely to take a week.

With all that work plus the service, parts and the risk a clock would not be restorable, you can probably see why I gave up on buying them in essentially unknown condition at £100 - £150 when there was no ready market for them fettled at £200 - £250 with a years guarantee.

Steel Cases

Some marine clocks have a painted steel case with a brass bezel and base. Treat as above through to degreasing then use a good gloss enamel on the steel part, Hammerite liquid paint will do the job, I have not tried the spray.

 

My 7" centre seconds clock in a steel and brass case, restored
some years ago with multiple coats of Hammerite gloss black
on the steel body.

For replacement parts, tools and consumables in UK Google Cousins and / or Walsh, at least the former requires you to register as a trade customer so that the distance selling regulations don't apply. A lot of the stuff you find on eBay are sourced from one of these and sold at a mark up.