WE Black 1968/71 2500D Housing - plastic or polane?

[TelePlay]

Got a very nice 1971 hardwired 2500D, all black. Out of the box it looked great (first picture). The base is dated 12/71, the ringer IV-71, the 425K network 11-71, the dial 4-75, the U3 receiver 2-70 and the T1 transmitter 9-70. So. it seems to be a late 1971 phone with the dial being a repair.

However, the housing is stamped 68 and handset is stamped 69. After taking the housing off and looking at it in bright light, I noticed crackalure or crazing on the housing. It seems to be paint but the emblems on the housing and handset are thin, crisp and clear to read - don't look painted. The inside of the housing looks strange, something like a thin coat of black paint on black plastic. I tried using alcohol on it and absolutely nothing came off with some firm rubbing.

So what do I have here? I'd like to clean it up, polish it in some places where the finish is worn but I don't have any idea of what I have here. Anyone seen this before or know what it is?

Please excuse the stray white lint in a lot of these photos, no scratches, just lint

[TelePlay]

More photos once they made it past security . . .

[TelePlay]

More photos once they made it past security . . .

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And some more photos once I got them past the security issue

[HarrySmith]

That is a strange looking finish.  I would try some Novus 2 on the inside to see what happens.

[jsowers]

Maybe they painted the sides of the phone so it didn't reflect the studio lights on The Rockford Files? 

[paul-f]

John,

I ran into a few phones with similar issues many years ago.  As I recall, I also tried several cleaning approaches without success before finally resorting to sanding and refinishing.

The pattern suggests there was an applied finish that expands and contracts at a different rate than the plastic underneath.

If it was done by an independent refinisher, we might guess that they didn't bother to research that feature before using the product.

If it was done by Western Electric, there were probably some very embarassed engineers and the product was replaced once the issue was noticed. We might be able to build a case for this if we find enough parts with similar dates to establish a time range.  If I find any examples in the project pile, I'll post dates later.

[TelePlay]

I ran into a few phones with similar issues many years ago.  As I recall, I also tried several cleaning approaches without success before finally resorting to sanding and refinishing.

The pattern suggests there was an applied finish that expands and contracts at a different rate than the plastic underneath.

Paul,

Thanks for that.

Just did a little work on the shell. It must be polane, or some version of it that was not compatible with the plastic causing the crackalure. Novus 2 hardly touches it but in a nice way. It's hard to see the crackalure on black so it only shows up in reflected light and even less if the surface is shiny.

After seeing the Novus didn't do much other than shine the surface, I used 4000 grit Micro-Mesh to wet sand some of the dull spots that I thought were chipped off or worn through paint. They were just dull spots in the paint. The MM cut the dull spots and took a bit of the shine off of the paint surrounding it but less than using 4000 MM on an unpainted housing. After the MM, used Novus 2 with my Ryobi orbital and got a really nice shine. The blemishes disappeared but the crackalure remained and with the extra shine, were harder to see. You have to hold the housing just right in bright light to see the crackalure.

Tried that in 3 or 4 places that needed help and all improved very well. The housing overall seems to be in good condition with its "special" finish. I really dread sanding all that paint off right now so will go with polishing the paint. Whatever the paint was, it is harder than the plastic itself, which is probably why the crackalure developed.

And, yes, the handset also has the crackalure but not as bad, not as visible as the housing, probably due to the thicker plastic used to make the handset and reducing the expansion/contraction effect.

[TelePlay]

The paint on this phone is very nice to restore. Polishes up very nice and quickly. However, the crackalure remains.

Working on the handset, I found proof of it being painted. What I first thought was a partial finger print turned out to be something similar but too uniform to be a print. You can see the crackalure around the print. It is not as pronounced as the housing but it is these, if looking at in just the right light. Was able to get some of the deeper scratches, too deep for Novus but not deep enough to give up on, using my wheel buffer with the white buffing compound.

[unbeldi]

I believe what you are observing is called crazing.  It happens on certain thermoplastic polymer surfaces and in some paint finishes.  The crazes are not really cracks just 'gaps' or very narrow areas of less dense material, but still bridged by molecular 'nets' of long polymer chains. They form in somewhat regular appearing patterns from surface stresses. They are microscopic and may only be some nanometers in width. The reason they can be seen is that light reflects off them. Polishing is way too course to cure them.
You probably have to sand the surfaces to take the paint off.

[poplar1]

. We might be able to build a case for this if we find enough parts with similar dates to establish a time range.  If I find any examples in the project pile, I'll post dates later.

John's 1968  housing is on a 12-71 phone refurbished 2-73.
Here is another black 2500D with a similar paint job. The phone is dated 2-71, with a refurb sticker dated 4-71. The black housing was made in 1969, and the Bakelite G1 handset is dated 1965, with 1971 plastic  caps.

http://www.ebay.com/itm/371281021569