Dials and HandsCopyright © David Boettcher 2006 - 2017 all rights reserved.
The very first watch dials from the sixteenth century onwards were made from engraved metal. In the eighteenth century the process of making enamelled dials was developed. Enamelling produces a dial that will never fade and can be easily cleaned, although they are fragile. Enamelled dials were expensive to make so in the twentieth century cheaper materials were used, usually something that could be printed onto a metal base. Such dials are prone to discolouration, fading, and spotting, but are extremely delicate and cannot be cleaned.
Sometimes enamel dials are described as "porcelain", but porcelain is made from clay and is used to make, e.g. bathroom sinks and toilets. In thin sections it is extremely fragile and totally unsuitable for making watch dials. Enamel dials are made with vitreous enamel. Vitreous enamel is called "porcelain enamel" in the USA, which often gets shortened to "porcelain", but in any language this is wrong.
The white, cream, or sometimes black, dials of pocket watches and early wristwatches were made of vitreous enamel, a glass coating on a copper plate. Enamel a coating and vitreous means that the coating has a glass like appearance. Enamel dials usually have a glassy reflective surface, but they can also be matt.
Vitreous enamel is made from powdered glass fused onto the copper dial plate by firing in an oven at high temperature, melting the glass and causing it to run together to produce a smooth glassy surface. First the white or black background is made, which might take four rounds of firing and smoothing to get the desired finish. Then the numbers and tracks are drawn on in black or white "painting enamel", which is fired at a lower temperature to fix it to the white background.
After firing an enamel dial is invulnerable to ageing or fading. Vitreous enamel dials will be cracked if they are flexed by being clumsily removed from the movement, but apart from this they will last forever.
Dial cross section
The cross section here shows how an enamel dial is made. A sheet of copper is cut to the correct size and shape, with holes cut for the hand arbors, and "dial feet" attached to its underside. Dial feet are small copper rods soldered to the underside of the dial that enter holes in the movement bottom plate and are held in place by screws, holding the dial to the movement.
The copper dial plate is coated with crushed and finely powdered glass. It is then heated in a furnace to about 800°C until the enamel melts and becomes liquid, fusing together to form a smooth surface and bonding to the copper.
The numerals and minute and seconds tracks are then either hand painted or transferred with a stamp in vitreous painting enamel, sometimes called vitreous ink, and the dial is fired again. This melts the enamel of the numbers and other details and bonds them into to the base layer of enamel. In the cross section I have shown a white enamel dial with a red 12. When the enamel of the numbers and other details melts and bonds with the underlying enamel it becomes virtually flat with the dial surface as the cross section shows.
In the drawing I have also shown how names can be added to a vitreous enamel dial with "enamel paint". Enamel paint is a totally different material from vitreous enamel, it is called enamel because it forms a harder, glossier, surface than other paints such as oil paint. However, unlike vitreous enamel, enamel paint can be dissolved by a solvent such as acetone or isopropyl alcohol.
Initially the numbers and tracks were painted by hand, but later an engraved copper block was used. The engravings were filled with vitreous ink and a gelatine pad used to pick up the ink and stamp it onto the dial. In this way many dials could be made accurately and quickly.
Names on the Dial
Throughout the nineteenth and early twentieth centuries British retailers only allowed their own names onto the dial. The concept of a "brand" being applied to watches was unknown, and the names of foreign manufacturers were simply not allowed. This only changed in the mid 1920s when Hans Wilsdorf started to advertise the Rolex brand in Britain and people started asking for Rolex watches. Wilsdorf says that when the Rolex Oyster was launched in 1927 he made the decision that he would insist that all Rolex watches carried the brand name on the dial. This was the start of a trend and other manufacturers soon followed.
This generally meant that watches supplied to the British market before the late 1920s or 1930 had dials with no name on them at all, they were left blank so that the retailer's name could be painted on in enamel paint. The importer might have offered this as part of his service to the retailer, or the retailer may have arranged himself for his name to be painted onto the dial.
Enamel paint is quite different from vitreous enamel and nothing like as durable. It is a solvent based paint applied cold with a brush. Often a retailer's name painted on to a dial in enamel paint has partly or almost completely worn away or flaked off over the years, whereas the rest of dial markings in fired vitreous enamel are still crisp and sharp. This is an easy indication that the name was painted on after the watch was made.
When you have looked at a lot of original watches without brands on the dial, seeing a manufacturer's name or brand on the dial looks wrong and not original. However these days people like to see a brand name so sometimes well known names are added to the dials of watches in an attempt to boost their value. A name painted on recently using enamel paint can be difficult to identify, it looks crisp and sharp and glossy, just like the rest of the dial. There are two ways in which such an addition can be identified.
- Look carefully across the dial at an oblique angle with a lens in good light. As the cross section shows, enamel paint stands up proud of the surface unlike the fired enamel numbers which are virtually flat. If you can see the name standing up like this it has definitely been added, but a very skilful painter will make the letters very flat so some painted names can be difficult to detect by this method.
- Wipe the suspect lettering with a solvent that dissolves paint such as acetone. Names fired into the enamel will not be affected by the solvent whereas names painted on later will dissolve and wash off, leaving the original enamel details of the dial intact.
Bear in mind that removing paint is easy, putting it back to match the original is difficult. I would recommend that you take some close up pictures of the dial and hands and send them to several companies. Give a detailed description of what you want doing and ask them if they can do it in the way that you wish. If you want the dial and hands to look exactly like they do now, paint colour and finish included, make sure you say so. Be as detailed as you can in describing what you want, don't imagine that they will know. Take up references and do your due diligence before committing your dial to them.
Think carefully about getting radium paint on an early dial replaced with luminous paint. The old radium paint no longer glows in the dark, so if you replace it with luminous paint which does, it will be obvious what has been done. I think this is a good thing, it makes it obvious that the paint is a modern luminous compound and not the old, non glowing, radium based lume.
I have used a couple of UK based dial repainters, but they tend to be quite expensive. US dial refinishers seem to be cheaper because they have a greater market and therefore are able to work on a larger scale, more commercial basis. A poll on the NAWCC message boards recommended a number of US dial refinishers, with International Dial Co. coming out as the clear winner. Next time I need a dial refinishing I am going to give them a try, and I will record the outcome here. NB: I haven't used International Dial Co. yet, and I don't have any connection with the company, so this is not a personal recommendation from me, I am just going on the results of the NAWCC poll.
The style of the hands should match the dial. In particular, if the numerals are skeletonised for luminous paint, the hands should also be skeletonised.
Poire Squelette hands
The correct shape for the hands of a trench watch is shown in the image here. The shape of these hands was called in Swiss/French ‘poire squelette’ (pronounced ‘skelette’) i.e. pear skeleton, after the pear shaped bulge on the hour hand. They are often referred to as "cathedral" hands because they look a bit like a leaded and stained glass window. This style is referred to in manufacturers catalogues of the time as "Luminous" or often simply "Radium".
Hands should also be the right length. The minute and seconds hands should terminate on their respective tracks, and the hour hand should point to or just touch the number.
Copyright © David Boettcher 2006 - 2017 all rights reserved. This page updated June 2017. W3CMVS.