Dial Plates

[TelePlay]

It looks like my dial plate (149B) is one model short of the new process (150).

And in a heck of a lot better condition that the one I got on a dial recently. This was more than crazing. Some of the little circular pieces were raised up and ready to break off the plate beneath, like just above the "C."

EDIT:  From what I could see with a high powered microscope in the more severe cracking, where the pieces were lifting off of the metal, was what seemed to be a rusted metal. Just guessing but I'd say it seemed like once the cracks developed, over a long time, moisture penetrated the cracks rusting the metal thereby "growing" the metal surface causing the cracked covering to rise up, to become more loose from the metal and the crack larger. Many of the cracks were still very close together and the metal surface beneath them not visible. It was the larger cracks and the areas where the cover "circles" were lifting and ready to flake off that made it possible to see the metal and what seemed to be rust underneath the loose circular chips.

[Sargeguy]

I would advise swapping it for a 132-B if you really want a white faceplate.

[cloyd]

Does anyone know what causes the discoloration and crazing?  Some of these old (acetate) dials are beautiful.  My guess is that the discoloration may be due to a smoking environment and the crazing is from the sun.  Perhaps it is due to oxidation.  Anyone?
Tina

[WEBellSystemChristian]

Does anyone know what causes the discoloration and crazing?  Some of these old (acetate) dials are beautiful.  My guess is that the discoloration may be due to a smoking environment and the crazing is from the sun.  Perhaps it is due to oxidation.  Anyone?
Tina

I think a lot of the delaminating may be due to a damp environment. Whatever adhesive WE used to hold the plastic to the metal backing might be weakened by moisture. I don't think it's just age like the yellowing it takes on with time, because I have seen so many different radical variations of weathering from these plates.

One of my more recent candlesticks had a dial that was very corroded, and the celluloid dial plate was destroyed and peeling like crazy! It definitely goes hand-in-hand with moisture, as I think Thermoplastic 302 housings do too. It seems that every plastic 302 I see that's covered in mold also has a tight-fitting or cracked housing, kind of like the celluloid dial plates. The more exposure to moisture and dampness, the more it seems to crack and peel off.

[unbeldi]

Does anyone know what causes the discoloration and crazing?  Some of these old (acetate) dials are beautiful.  My guess is that the discoloration may be due to a smoking environment and the crazing is from the sun.  Perhaps it is due to oxidation.  Anyone?
Tina

I think I explained that briefly earlier here:

Just a small correction as to the material of the plate.

The plastic layers on the No. 149 type plate were made from cellulose acetate, the same material as telephone housings.   Cellulose nitrate, traditionally called Celluloid, was rarely used anymore at this time, but was used for motion picture films.

The problem with treating these face plates is that they easily separate from the metal substrate after this much time. The cellulose acetate shrinks and stress builds internally apparently in excess of the strength of the bonding to the metal.  This stress also often causes flaking, crazing, and cracking.

Cellulose acetates are notorious for shrinking over long time, because the material decomposes into water and carbon dioxide and simply diffuses out of the bulk.  Tenite telephone housing literally shrink onto metal structures. In case of the colored 302s, we commonly find corner cracks.  Here is an extreme example of an AE 34 that is an inch smaller than its base: http://www.classicrotaryphones.com/forum/index.php?topic=8408.msg92829#msg92829 (Paul-F's 2013 Find of the Year).

A friend told me he had almost pristine 149 number plates that were carefully stored, and when checking on them after years, he found that some had the plastic completely separated from the metal substrate.

The Tenite that Western Electric used for the 500-set was a modified version of cellulose acetate,  called cellulose acetate butyrate (CAB), which was at the time sold by Eastman Kodak also as Tenite II. Those housings still today show little or no shrinkage of significance.

[Ktownphoneco]

I agree.       The plate itself is steel.       It's either painted and / or inked, or a combination thereof, to give it the white background and the red and black numbers and letters.    The dial's face is then covered with celluloid.       But the fine edge around the dial's circumference, isn't sealed, and as Christian has pointed out, moisture gradually works it's way in between the the painted / inked dial face and the celluloid coating, causing the celluloid to lift, craze or peel.       I'm sure the yellowing is purely the result of exposure to the sunlight.    The varying degrees of yellowing, are most likely directly related to how much sunlight the number plate has been exposed to over the course of it's existence.     I have several celluloid number plates.    One or two are "very" yellowed, while one or two others are about as close to perfect as one could get.     I think it's a safe assumption that each and every Western Electric automatic telephone set equipped with a celluloid number plate, were exposed to any number of different situations involving moisture and sunlight, which is most likely why a large number of these plates that still exist, vary widely in their appearance, from pristine, to a total mess.
Look at the picture below.      It brings up another possible reason as to the various degrees of yellowing.     Notice the plate on the left.    It was made in 1937, while the 2 number plates to it's right, were both not only made in 1938, they were both made in the first quarter of that year, and they're both more yellow in appearance than the plate made in 1937.       That makes me wonder if there may have been issues, or differences in the celluloid formulas, which caused the yellowing to be more pronounced on some plates than others.

But I doubt we'll ever find a BSP that spells out the reasons for certain.

Enjoy the rest of the day.

Jeff Lamb

[Ktownphoneco]

Karl, I totally missed that.      Very interesting.    That kind of blows the moisture theory out of the water. (no pun intended) .

Jeff Lamb

[unbeldi]

Well, water presence has its destructive powers, as it can easily become acidic and corrode the metal surface microscopically weakening the plastic bond.

There are two patents by Cox et. al.  from Philadelphia who by 1932 invented the all plastic number plate which eliminated the metal backing and closed the large opening of the 132 plate.  Western Electric field-tested the plates in 1933 and 1934 but for whatever reason decided against them—an inference, because they opted to produce the 149.
But Cox suggested that cellulose acetate plates can be "easily" refinished after surface cleaning by dipping them into liquid cellulose acetate without damage to the way their lettering was applied.  I don't know if this was an influence for WECo, but WECo certainly adopted the closed center.

Looking closely at the pictures of your plates, it seems the yellowing is creeping toward the center from the edge, fading toward the center.  Is it just on the surface?  It would be expensive to find out and try too much surface cleaning and risking damage.  But I have the feeling it can probably be reversed by gentle bleaching or treatment with micropolishing cloth.

Telephone housings have a great deal of variation of yellowing too, ranging from almost golden to light shades, as can be seen from this pictures of several ivory sets I have restored by bleaching. This indicates the yellowing is only in a very thin layer on or in the surface.

[unbeldi]

Tina's 149 plate on the 202 is actually in very nice condition, the darkening is just part of its historical value, IMHO.  I wouldn't change it.

On other matters, I am admiring her 5J dial with that BUckminster 2— number card.

Where did you find it?

I believe there was only one BUckminister exchange in the country, I could be wrong but I have searched and never found another.  It was located in the Flatbush district of Brooklyn, NY.  I also have a telephone from that exchange, but almost 20 years earlier than yours. I have even found the exact address where mine was installed in the mid 1930s.  Yours appears to be from the early 1950s and that number was owned by a business or the business owner in the early 1940s, probably too far removed time-wise to make a statement for the 50s.

[Ktownphoneco]

The plate on the extreme right (38-I) is why I was leaning towards the moisture theory.     A combination of air and moisture was also a consideration.     In most cases, that seems to be a general pattern when it comes to yellowing and peeling; from the outside, in towards the center.      I think if Western had completely covered the number plate so that they were more or less, completely sealed from air and moisture, and barring physical damage along the way, the outcome 77 years later, may have been totally different.


Jeff Lamb

[cloyd]

On other matters, I am admiring her 5J dial with that BUckminster 2— number card.
Where did you find it?

It came with the phone that I bought off of eBay.  It wasn't well packed and the receiver cracked both sides of the case.  That added to the crack I knew it had in the back.  It was shipped from Ormond Beach, FL.  The dial is nice and I, too, loved the dial card. I'll ask the seller if he knows anything about it.

Tina

[cloyd]

Unbeldi,
How did you know that my phone was owned by a business owner?
Tina

[unbeldi]

On other matters, I am admiring her 5J dial with that BUckminster 2— number card.
Where did you find it?

It came with the phone that I bought off of eBay.  It wasn't well packed and the receiver cracked both sides of the case.  That added to the crack I knew it had in the back.  It was shipped from Ormond Beach, FL.  The dial is nice and I, too, loved the dial card. I'll ask the seller if he knows anything about it.

Tina

A lot of New Yorkers retired to Florida, of course.  It seems they would just pack up the house including telephones and moved south.  Mine also came by way of Florida.

Here it is:

[unbeldi]

Unbeldi,
How did you know that my phone was owned by a business owner?
Tina

Well, I don't know about your phone.

I found your number in a Brooklyn newspaper, it was a classified ad, someone was offering the business for sale.  But this was 1938, therefore my comment.

I also have a Brooklyn Telephone book of 1943, but I don't think I found it in there.

I still have the newspaper page, it is attached.    Your entry is highlighted in green,  it was a radio store that was for sale.

[Dan/Panther]

Acetate, Nitrocellulose, tenite are all early to mid 20 th century synthetics, that are notorious for Shrinking, discoloration, and checking.
Acetate movies, can shrink and roll to the point you can't project them any more. They also develop VS syndrome, where they smell like Vinegar, If you have a film that smells like vinegar, you need to isolate it, it causes the film to shrink, and it's contagious by contact. If you project a film with VS, then project another one, without cleaning the projector, you have contaminated the other film. Very disheartening, when you spend hundreds for a film you like, and after a couple years you take it out to view it, and it smells like Vinegar. NO CURE. Nitro finish like used on guitars is notorious for checking and yellowing. Instead of panicking, everyone decided it's Character. Tenite, well we all know what happens to that.
D/P