If you’ve been shipped as many Elektronikas as I have, from a variety of countries with very different ideas of what due care for postal parcels means, you’ll eventually encounter something disheartening like this:

You may have purchased a clock where a previous owner changed the faceplate to plastic or glass without the masking areas, or there is extensive damage to the silkscreen on either side of the glass. Or, you might be displaying the clock somewhere you don’t want random people tapping on the glass and possibly breaking it.

In any of these situations, you’re going to need a replacement faceplate. Unfortunately, it isn’t a simple matter of ordering one online from the factory – they haven’t made these clocks for many years, and any replacement glass is likely to encounter the same unkind treatment from the international postal services that got you into this mess in the first place.

Fortunately, I have created a solution for this – replacement acrylic faceplates which are nearly indistinguishable* from the original. I start with precision-cut pieces of colored acrylic (plastic). The pieces I use are cut from 1/8″ (nominal) thick sheets, the same as the original glass. There are four possible choices for color if you’re trying to match the original glass, two of which are much better than the others:

• 3030 “Glass green” – this is a color designed to mimic real sheet glass. It has a very minimal green tint, just enough to give the edges the green color that real glass has. We don’t care about the edges as they’ll be inside the frame. This is the ideal material for replacing clear glass faceplates.
• 2111 “Light green” – this color appears to be lighter than the original green glass faceplate, but when installed in the clock, provides a very good approximation of the original green glass color.
• 2092 “Dark green” – this color is not recommended. While it seems to be the closest match to the original green glass when comparing materials side-by-side on a white background, it imparts much more of a green tint to the tubes and decreases the brightness substantially.
• “Clear” – this is also not recommended. It looks quite a bit different from real glass. 3030 is a better choice when replacing clear glass faceplates.

Note that these color codes are the ones used by Altuglas International for their registered trademark Plexiglas® product. Other manufacturers also offer acrylic sheet plastic and generally use the same color codes as a common point of reference. Those colors may differ subtly from the reference Altuglas colors.

If you’re trying to change the appearance of the clock, you’re still limited to colors in the green to blue range. Since those are the colors given off by the VFD tubes in the clock, you can’t do something like using a sheet of red plastic – there’s no red light available to pass through the plastic. Unless you have one of the very rare version of this clock which uses orange MTX-90 tubes, of course.

On the original glass faceplates, lacquer paint was applied to the glass via silkscreen. That’s certainly the fastest and most accurate method for mass production, but would require a lot of prep work for making a few replicas. Instead, after carefully cleaning the acrylic, I applied masks cut from 3M 2060 green painter’s tape, in the shapes of the 4 clock digits plus the colon indicator. Remember, the paint goes on the inside of the glass, so the pattern is reversed from the normal view:

If you are making one of these replicas yourself, this would be a good time to check your mask by sliding the plastic into your clock and making sure that the mask lines up properly with all of your tubes. Even small measuring errors will be magnified as you repeat the masking process across the plastic. After removing the plastic from the test fitting, make sure that it didn’t pick up any contaminants on the masked side – if it did, they will ruin the completed paint job.

Next, I masked off the back side (which will become the front / outside of the completed faceplate). You may be wondering why I didn’t simply leave the protective paper in place that comes on the sheets – that’s because I needed to see through the plastic in order to properly position the mask pattern. I applied 5 thin coats of Valspar 68100 gloss black spray paint, which is a special paint designed to adhere to plastic. One spray can will be sufficient to paint 3 replica faceplates. I alternated painting lengthwise and across the faceplate, waiting 10 minutes between coats. After the last coat was applied, I let the paint dry for 2 hours:

I removed the tape that covered the unpainted side of the panel and carefully inspected the paint for any flaws:

This particular faceplate is for a newer 11-tube clock, as shown by the wider border below the digits and colon. The 12-tube clock has approximately equal border widths, top and bottom.

I then proceeded to carefully peel off the painted masking tape to expose the clear areas of the faceplate:

Here’s a closeup of the painted side showing the finished paint job:

After leaving the paint to fully dry for two days, I prepared to install the vinyl decals that I had custom-cut for the project:

After carefully applying the decals, I had completed replicas, ready to use. From bottom to top:

• Original clear glass 12-tube faceplate
• Replica 12-tube faceplate in 3030 plastic
• Replica 11-tube faceplate in 2111 plastic

These are certainly good enough to look original until examined very closely. See the footnote below for ways to detect replicas.

Here is a picture of the 11-tube 2111 replica installed on the clock with the broken glass shown at the top of this article:

* I have intentionally made it easy to detect a replica versus an original, to prevent people from passing off the replica as an original piece. There are a number of clues, some of which I’m keeping confidential. However, I am documenting three of them here:

• The “Э” in Электроника is very circular and doesn’t appear to be italic in the original, while my replicas use a more oval shape with an obvious italic tilt to the letter.
• The digit “7” in the original has constant line width and only uses straight lines, while my replicas use a slightly curved shape of varying width.
• If you tap gently on the faceplate with your fingernail, a replica will make sort of a dull “plonk” sound as the plastic is more flexible than glass. A genuine faceplate will make a sharp “tink” sound.

This entry was posted on Wednesday, August 22nd, 2012 at 4:56 am and is filed under Clocks. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.