Bakelite - keeping the gloss
Everyone agrees, there are few finer sights than a gleaming article made of bakelite. Bakelite, named after Baekeland, its Belgian inventor, has been described as one of the most gorgeously tactile materials ever made; it is hard and glossy yet capable of being moulded into fine detail. When new it carries a lustrous sheen which is difficult to better, even in black, which is otherwise a pretty lifeless colour. In fact there are few man-made objects more functionally attractive than a gleaming black bakelite telephone, although it doesn't really matter whether it's a radio, telephone or a TV receiver... there's just something immensely appealing in the fine details and hard lustre of that plastic. It's clear that bakelite was made in several different grades; that used around 1950 for interior components of motor cars (dashboards and steering wheels) seems to age and discolour very little. On the other hand, if you compare a Bush TV12 television with the later TV22 model, it is all too clear that the older set had the better finish. The bakelite of some telephones was even worse and soon came to look more like pumice stone. Quite possibly the better variants contained more resin and less filler material. No doubt it was cost-cutting that reduced the resin content. What a shame then that the lustre vanishes all too fast. So many artefacts made of bakelite seem to lose their gloss and end up brown and porous.
It doesn't seem to have anything to do with the age of the item, so why does this happen and what can be done about it? First, let's look into the technology. Bakelite is a thermoset plastic, that is a plastic which starts molten as a liquid but once solidified, does not revert to its liquid state when heated. In crude terms it consists of a resin (which has the glossy appearance) plus a bulk filler material, usually wood flour. The shiny surface you see and admire is the top layer of resin but this is often very thin. Once rubbed away through atmospheric action, over-enthusiastic polishing or by scorching in the sun's rays, it is lost and nothing will bring it back. You are then left with a pitted mixture of resin and wood flour (or asbestos powder) and wood flour, being very fine sawdust, is not a particularly glossy material. It is this wood flour that looks brown and porous once exposed. Cleaning should precede any physical restoration of plastic mouldings. De-grease first, if necessary, with methylated spirits and a hard cloth. The restoration techniques you use will depend on whether the top layer of resin is intact; let's assume first that it is. Bakelite and other plastics which are only lightly soiled should be cleaned with Paste Polishing No. 5. This is a waxy polish compound, with a mild abrasive, and extremely effective. It will remove any film of 'gunge' and leave a smooth, glossy surface. Everyone who sees this cannot believe how good it is, far better than the metal polish that people used to use to clean bakelite! PP No. 5 is the stuff the GPO formulated for refurbishing old bakelite phones to new condition, by the way, and you can buy it either in bulk from the manufacturer or in small quantities as Baykobrite from Radiophile Publications, Larkhill, Newport Road, Woodseaves, STAFFORD, ST20 0NP. The paste should be rubbed on with a hard cloth, then removed and buffed up with a soft cloth. Alternatively you can use Solvol Autosol or similar paste (remove with white spirit) to rub down to the clean plastic underneath, but this always leaves a white powdery deposit which is difficult to remove from cracks and mouldings.
If the surface is already rough and porous the technique described will not help. The remedy then is to cut away the discoloured layer with a hard brush and grinding paste ('soap') if you have a buffing machine. Otherwise use an abrasive polish such as T-Cut or Color-Bak (car paint restorers) or Bluebell (metal polish). Then let this dry, wipe off the residue and inspect the bare material exposed. If it has retained its pigment, polishing with a liquid real wax polish will suffice. Buff it up to a high gloss and be prepared to repeat this exercise every twelve months or so. If the bare material is discoloured, you will need to add new pigment. For black there is an intense black stain in car accessory shops called Back to Black - use it but try not to get it on your clothes. Otherwise you can use shoe polish (work it well into the pores of the bakelite) and buff it off several hours later. Several applications may be required. Then finish off with liquid wax polish. There are some people who prefer to avoid the hard work and paint low-gloss tung oil varnish on badly dulled bakelite (this usually takes about three coats and gives a very fine finish, not as shiny as lacquer). You need to use a lint-free cloth to apply the varnish and for details and crevices, use a tape recorder head cleaning swab. - these have foam rubber heads instead of spun cotton). This method, which aims to restore the finish by filling the microscopic pits with a clear substance, is valid if the bakelite has not lost its colour.
If it has started to go brown, on the other hand, sterner methods are necessary. Small cracks and chips in the bakelite can be filled with soft furniture restoration wax, boot polish (my favourite) or car body fillers (cellulose paste or fibreglass resin types - you can buy these which are already tinted black, intended for filling cracks in black plastic car bumpers). Clean breaks can be joined with Superglue (cyanoacrylate) or Araldite (epoxy resin), though care is needed to prevent smears of glue showing. These techniques work. I know they do and they work very well. There may be other products and methods, so let us know if you can help.
Repainting bakelite
Finally, some bakelite products were painted another colour and we may need to restore these paint finishes. Bakelite itself is generally either brown or black, simply because the moulding powders for bakelite had to be dark colours to mask the wood flour and asbestos dust filler material used. What many people call coloured bakelite isn't bakelite at all; these coloured plastics were often too expensive to use for utilitarian products. Paint was often used for bright colours, this being a lot cheaper than choosing self-coloured plastics of these colours (even if not quite so attractive). Certain brown bakelite radio cabinets were spray painted to provide a contrasting colour (e.g. primrose panels on brown bakelite); equally some bakelite telephones, such as the STC 'Antwerp' phone, were given paint finishes over black bakelite to provide additional colourways. For repainting bakelite an enamel finish adheres best, preferably an eggshell paint which is not too glossy. A hardware shop will have some spray colours which may match, otherwise you will need to go to a specialist paint supplier (see previous chapter). Vintage TV and Radio Supply (USA) has two products, Barrier Coat and coloured lacquer enamel. The former is a basic primer for rigid plastics and bakelite; it ensures good adhesion and provides a barrier between the plastic and finish coatings. The coloured lacquer enamel is fast drying and has a superior hiding power. It comes in just two colours, gloss black and antique ivory. In practice, most cellulose or enamel spray paints could substitute for this product.
Advanced bakelite repairs It is possible to repair broken bakelite in a way that is very hard to detect. The first thing is to make solid joints and if you are lucky, you can piece the bits together and glue them in place with superglue (cyanoacrylate). Doing this slowly and carefully is the main secret; it may take quite a bit of 'dry runs' to get the three-dimensional jig-saw to go together properly. Plasticine will help keep the pieces together while the glue cures. For pieces under mechanical stress, superglue will probably not work; in this case you will need to use a modeller's drill to make holes for inserting short pieces of wire to pin the joint in several places. A traditional slow-setting epoxy glue such as Araldite is used to make the joints and this can be built up behind the joint out of sight to give added strength. When nearly set, surplus Araldite can be trimmed away with a sharp blade. An alternative method which also has a lot to commend it is the use of glass-fibre cloth and resin (bonding paste), as used for patching car bodies. The materials are used on the inside of the case to be mended and the trick is to use a file or grinding tool to thoroughly roughen the surface. Using a putty knife or wooden spatula, the roughened area is then covered with a thin layer of resin (about 1/16th inch thick). A piece of glass-fibre cloth is then pressed on, smoothed out and left to cure. Once fully set another thin layer of the bonding paste is spread over the cloth for extra strength. This can be sanded for a smoother finish if desired when cured. Yet another possibility is Loktite BlackMAX adhesive, which is a cyanoacrylate that has rubber dust loaded into it. This helps the impact resistance and also gives a black colour. Some hairline cracks will remain and these can be filled with the self-curing black resin body-filler paste available at auto accessory shops. Once cured you can use very fine wet-and-dry paper (as used for car body work) to smooth the joints until they can no longer be seen or felt. Finally polish with Paste Polishing No. 5 (Baykobrite). For brown bakelite you could mix artist's powder paint with clear epoxy glue but be sure to mix in the powder extremely thoroughly.
Seized bakelite parts
A recurring question is how do you unscrew the earpiece cover on the handset of an old bakelite phone? With great care is the facile answer. One method is to dripping some penetrating oil into the minute gap around the cover (the oil won't harm the bakelite), leave for 24 hours and then get a better grip on the cap, either by wrapping several large rubber bands around it or better by using one of those thin, flexible neoprene mats specially made for getting a grip on obstinate objects. There are also special tools sold in kitchen shops for unscrewing lids on jam jars and at car accessory shops for removing oil filters; the tools work in similar ways and may be of use. Failing this heat can help; you place the offending object in a bowl of scalding-hot water (and take great care!). On bakelite handsets (of the British pattern) it's not always clear how the mouthpiece is released. Actually this is very easy; there's a small hole in the rim of the mouthpiece, behind which is a metal detent. Forcing a thin metal point (such as a thumbtack or drawing pin) into this hole will release the mouthpiece. |
