Repairing & Restoring Clock Cases from the early 20th Century

I got this email so I thought I would do a blog post on this. No pictures for a change – this is a hardcore repair article for those who want to get stuck to a good restoration for pleasure and satisfaction.

“Hi Justin,

I am a clock / watch fan and a bit of an amateur repairer.  I have a number of mechanical clocks around the house that I have breathed life into … most of which have come from lofts and sheds and have been given to me as non-working projects by friends and family.  None are worth much in the material sense but most have some kind of sentimental value, like the mantle clock that was given to my Grandparents on their wedding day and was in turn given to me by my mother.

I bumped-ono your web site when looking for tips on cleaning wooden cases.   I would be very grateful of any tips that you may wish to share on cleaning wooden cases and in particular replenishing the wood – thank you.

Best regards,

John

Colchester”

Repairing and restoring clock cases, specifically those from the early to mid 20th century, can be a minefield. The main problem here is that the veneers used were generally not that high quality. They tend to be thin and dyed. This means if you try to work them they break.

You have to commit to doing the whole case. If you try and refinish part of it you will either create a clock in two colours (one of which you dont want) or you will change the finish on the area you are working on both in terms of texture and colour. If you then apply varinish or laquer to that area it will be very obvious and you will have to start again on a case that was worse than when you started.

Doing the whole case does not necessarily mean stripping off all the old varnish. If the varnish is simply starting to flake then

  1. Use a green scratch rag / sponge to remove the flaking varnish. Apply pressure evenly when you do this so that you dont wear off the varnish in a patches.
  2. Mix 1 part varnish with 2 parts paint thinners. This will create a very thin mixture that you can apply with a sponge. Dont use a brush – its the wrong tool for this and will leave marks and streaks. Apply the varnish thinly so that it is not capable of running / pooling.
  3. Leave 30 minutes between coats and apply 3 coats.
  4. Once dry, buff to a high sheen finish and then use silicone based polish to give it really high gloss UV protective coating.

The above assumes the varnish is just starting to flake and the overall damage isnt that bad.

If the clock has broken sections in its varnish or is excessively worn then you need to strip the old finish away. This is not complicated and simply use regular paint stripper by following the instructions on the tin. All work well and its just a matter of being patient and maybe applying a couple of coats of stripper.

Once thats done give the case a good wash and let it dry thoroughly. You can now apply wood stain to the case before varnishing. When it comes to varnishing you can use a brush but by far the best results will be achieved with the thinning and sponge method described above – lots of layers thinly applied is the rule to follow on this one. If you slap it on thick you will end up with run marks in the varnish, no matter how confident you might be about it applying as you want – just spend the extra time and reap the rewards.

One last thing – your clock might have a toned finish – this being the case avoid the complete strip down option as its hard to replicate.  If thats not an optionthen it can be done by using thinner with a few drops of black paint disolved in it. This allows you to dab on more gradually in the areas to be shaded / toned. The advantage of doing it this way is that you can correct mistakes while you are doing it by simply wiping your dye mixture off with the same thinners you used to dilute it. Also, if you want the darkness to seep into the grain to effect a sort of striped woodgrain effect then you can apply the dyed varnish and then rub it off the relief of the wood. This leaves the stained varnish in relief of the woodgrain. This achieves approximately the same finish as on the originals or these two toned clocks.

One last last thing….invest in a small set of oil paints. Oil paint can be mixed on the palette to get a good colour match and the texture you can apply with a brush makes it easy to simulate wood grain. Give this 48 hours to dry before applying the varnish over the top. Its a great way of filling veneer chips as the paint is thick enough to be used as a filler for most jobs although you will need serious drying time on it.

Im always happy to help people on restorations so just email me if you have any questions or need help on your job.