Gauge face/lens

Dr.Jeff

Dr.Jeff

True Classic
There's a great thread by @twincam69 about rebuilding Veglia clocks and I've been playing with some of them. These are the round analog clocks in models like the 124, not the square digital ones found in the X. They have a clear plastic lens over the face of them that always turns yellow over the years. This is true for all of those round gauges, not just the clocks. I recall someone was successful at cleaning the yellow off somehow. I don't recall if that was here of another forum? Anyone know a procedure for accomplishing that?
 
The other gauges have glass lens. I replaced the plastic clock lens with a Maglight flashlight lens.


Dr.Jeff said:
There's a great thread by @twincam69 about rebuilding Veglia clocks and I've been playing with some of them. These are the round analog clocks in models like the 124, not the square digital ones found in the X. They have a clear plastic lens over the face of them that always turns yellow over the years. This is true for all of those round gauges, not just the clocks. I recall someone was successful at cleaning the yellow off somehow. I don't recall if that was here of another forum? Anyone know a procedure for accomplishing that?
Click to expand...
 
No idea if it works on clear plastic, but recently watched this video that explains how to brighten age yellowed plastic.

 
Mark said:
The other gauges have glass lens.
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I might be remembering it wrong, but I thought that depended on the year. Didn't some years have plastic in all of the gauges? Regardless, that isn't important. Trying to fix the yellowed clock lens is my objective.

Nice idea with the flashlight lens. I was also wondering if any of the glass lenses found in various industrial gauges (like air pressure, etc) might fit. But I recall someone was successful at cleaning the original one.
 
motoTrooper said:
No idea if it works on clear plastic, but recently watched this video that explains how to brighten age yellowed plastic.

Click to expand...
That guy is a real character. From his dialogue he appeared to be using some sort of hair bleach? But the label on the bottle seems more like a hair conditioner? I'm not clear exactly what he did frankly.

I wonder if any bleaching product would attack the acrylic lens and make it crack or fog it?
 
Why not use a headlight polishing kit? Seems like it is the same problem to be solved.
 
JimD said:
Why not use a headlight polishing kit? Seems like it is the same problem to be solved.
Click to expand...
Most of the "yellowing" on headlights isn't the plastic lens, but the UV protective coating that is over them. And most of the headlight cleaning kits merely remove that UV coating, and thereby the yellow. However I don't think these clock lenses have the same coating, so it may not work the same? Likewise with a typical plastic polish; they are good at removing contaminants from the surface but I think this is deeper than that. However I just began reading a interesting discussion that may prove me wrong on that last point....

This link also answers the question about the hair bleaching product in the video that @motoTrooper posted:
www.exisle.net

De-Yellowing plastic - the stain isn't permanent after all - Creators Corner

Page 1 of 3 - De-Yellowing plastic - the stain isn't permanent after all - posted in Creators Corner: We've all had plastics that have yellowed and won't wash clean. Sometimes it's just a pale gray mouse or keyboard slowly going beige; sometimes it looks like a severe "nicotine staining" and we...
www.exisle.net www.exisle.net

I didn't finish the article but it sounds like hydrogen peroxide may work if left in the sun?
 
It seems like the yellowing and clouding on the plastic lens is something all through the lens thickness rather than imperfections on the surface but have never tried to restore one.
All spider gauge lenses are glass and their problem is they get an oily coating on the inside that makes them fog up with moisture. Easy to remove and clean with glass cleaner.
 
Must not be all of them were glass. Mine was a '78 spider. I nicked the "glass" when using it as a template. I was using an exacto knife to draw an outline and mark the stem hole. I aquired the car with 166k miles on it. Thinking about Carl''s comments my first thought was maybe the glass had already been replaced with plastic. But, now I remember the soft metal bezel was still completely unmolested.
 
I finished reviewing the discussion I linked earlier about removing yellowing. Turns out they were not discussing clear plastic, but white molded items (like the light switch in @motoTrooper's linked video). So I don't know if the mild bleach (peroxide) will work on these clear lenses. But I decided to try it - nothing to lose. I just submerged the lens in a small bottle of it and set it outside in the sun, as our UV levels are off the chart. But I don't have any "OxyClean" to catalyze the peroxide. Funny because we had a container of it sitting on the laundry shelf for years; it didn't do anything for the wash so I eventually dumped it. And the peroxide I used is the weaker home variety. But the discussion says it may still work so we'll see what happens later today. I believe I also have some plastic polish in my car detailing bin (you know, the one that hasn't been opened in decades - with all sorts of products sitting in new unopened containers). I can give that a try as well. Worst case scenario I'll make a new lens like others did.
 
In regard to 124 gauges, I meant all the gauges, except the clock had glass lenses. Every clock I have seen had plastic lenses.
 
A little update on restoring the yellowed clock lens.

After reading about the peroxide approach I decided to give it a try. I'm using a weak solution (3%) and no oxidizer to boost it. But after a few hours in our super-high-UV-level sun it did begin to lessen the yellowing slightly. I replaced the peroxide with fresh and I'll leave it out in the sun longer to see how much it improves. But honestly I'm not overly optimistic from what I see so far. It doesn't appear that it will eliminate the yellow, just lessen it some. Not good enough.

Next I tried some various plastic polishes. I went through my bin of car detailing stuff and pulled out anything that looked like it might help. Some cleaned off any "schmutz" but did not improve the yellowing...Windex would be as effective. Others removed some of the yellowing but caused a "haze" - tiny scratches in the plastic...that seems to indicate the yellowing is on the surface (as described in some articles) and not all the way through the plastic. Some actually left a dingy tan/yellow film...kind of counterproductive. And some didn't improve the yellowing but made it look nice and shiny - although it felt oily...which I'm sure will attract dirt.

While working with selection of plastic lenses I had on hand I noticed that most of them were already scratched. Mostly mild swirl marks, I'm sure from previous cleaning with a paper towel on a dirty surface. So even if you could get rid of the yellowing and really clean it up, you'll likely not be 100% satisfied with the result. In fact the improved clearness will make the scratches/defects more obvious.

At that point I decided the thing to do is just replace the old lens. Glass would be ideal, so I looked at the glass lenses in a multitude of industrial gauges around my shop (pressure, flow, etc). The majority are too big diameter, so it might be difficult to find the correct size replacement going that route - although there might be a cheap oddball size gauge at Harbor Freight that will work for a couple bucks? However I think the best approach is either invest in a glass replacement lens from one of the Italian car vendors, or make a new plastic one as others described; depending on your budget, goals, skills, motivation, etc. In my case I don't want to invest any more into this clock. It was in bad shape to start with and this all stems from an experiment to repair it, as described in @twincam69's excellent thread:

Veglia clock repair 124

So I decided to see if I could replace the guts on a 124 Veglia clock since I’ve never seen one that works. I thought I’d buy one of the Luch 12v quartz car clocks off eBay for $12 as a starting point. It turns out that the works are an updated version of the veglia and all the mounting studs...
xwebforums.com

In that process a inexpensive clock from Belarus is gutted to use the new mechanism inside the old Veglia clock body. And the new donor clock comes with a plastic lens. It is too big diameter but easy to grind down to the right size. So that's what I did, but any clear plastic could be done the same way.
 
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