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Solvent Polishing ABS

Started by, June 26, 2011, 05:31:59 PM

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In the 1970s I had the opportunity to tour the WECo distribution center in Los Angeles. The center included the WECo telephone refurbishing operation. I was not collecting telephone then, so did not pay close attention. They showed how they refurbished plastic telephone items. For items that were not trashed (no cracks, etc.) they were put through something like a giant dishwasher, then sent into some kind of chamber where they were sprayed with a solvent and heated. I saw the end result; plastic items that looked new. The only evidence of "painting" I saw was a room where they were refinishing coin telephones by spray painting the box exteriors.

I have often wondered about that solvent spraying operation since I began collecting. I recently obtained the WECo patent that describes the solvent spraying operation and an earlier patent for ABC Industries that describes essentially the same process. I don't know how WECo was able to get a patent with the ABC patent already existent. The main chemical described in WECo's patent is dichloromethane. In ABC's patent, their main solvent is described as methane chloride. The two chemicals are the same thing with different names.

I have posted both patents on Google DOCs if you are interested.   WECo's patent  ABC's patent



Edit: Above links require Google permission, the Patent File 3,807,054 is attached as a PDF fiel


Chuck, the other three that you sent in a different post opened just fine, but I'm having trouble with these two. The first one said that I don't have permission. Do you know what the patent number is for the first one? With the second one you need to put a period where the comma is between tinyurl (.) com. Even when I do that it is hard for me to read. I have better luck with this one < > or this one < > Thanks for taking the time to share these.
Doug Pav


I have been saying all along there must be a way to chemically restore our discolored phones! This is what I have been talking about. Now we need a chemist among us to come up with a solvent mixture we can use on our phones. Imagine being able to restore the beauty of a phone without all the wet sanding and polishing! The patent talks about combing with freon to vaporize the solvent so we are going to need another process.

Do we have a chemically inclined member who would be willing to step up and figure this out?
Harry Smith
ATCA 4434

"There is no try,
there is only
do or do not"


I changed the permissions on the WECo patent. It should open now. I thought I had open permissions before. I believe the WECo patent number is 3443008. For some reason Google DOCs seems to degrade readability. Going direct to the online patent leads to a better copy. If you have further problems, let me know and I will try to provide a direct link.


I don't know if the process eliminates age discoloration, which micro-mesh wet sanding does. In the '70s and '80s WECo may have not been contending with age discolored plastic. But I may be able to let you know. I have ordered some methane chloride to experiment with.



Quote from: on June 26, 2011, 09:49:57 PM

I changed the permissions on the WECo patent. It should open now. I thought I had open permissions before. I believe the WECo patent number is 3443008. For some reason Google DOCs seems to degrade readability. Going direct to the online patent leads to a better copy. If you have further problems, let me know and I will try to provide a direct link.

Chuck, I still can't get into the WE patent, but the ABC one opens up just fine. The WE one still comes up with a login. I've tried on two different computers--same results.

Thanks for posting these documents for us to see.


Send me your direct email and I will send you a copy:



Or go here < > and look up patent #3443008.
Doug Pav


Here is the pdf file for the WE patent, attached below. It's small as pdfs go.


Thank you. You answered a question I had in mind - whether or not multi-page documents can be upload on the Forum Web site.



Chuck, you're entirely welcome. I think as long as they're small, it's no problem. I don't think Dennis wants this to become a document repository since TCI has a excellent one already. But the occasional small pdf file should be fine.


I was in the basement categorizing a few dozen phones I've acquired for stage use and had not looked at them until now. They were 500 C/D and DMs of various colors.

I first noticed the WE logo box on one beige phone handset could hardly be read and the surface around it was quite smooth and shiny.

I then discovered the WE logo box under the hand hold on a light blue base was also very hard to read and very similar to the beige handset letters, The blue handset had crisp and easy to read lettering.

Given the dates on these phones (60's networks and ringers with 70's repair dates), it seems the handset and base could have been subjected to chemical refinishing at a WE plant. The once crisp edges of the letters were rounded over and some letters were so "melted down" they were hard to read.

I remember you said you protected those parts of the plastic when doing your experimental work. Do you think I have two WE chemically refinished pieces? I wouldn't think WE would take the time to protect their logo.

It doesn't matter much other than I may have an example of what their process did to WE logo lettering on ABS phones.


I don't think they covered the logo. I too have seen fuzzy logo on refurbished 500 sets. I believe they were happy with an overall finish that looked "new" to the subscriber.



Freon is no longer available for those types of applications, since it was eating the ozone layer (maybe that's why phones started fading more in recent decades?). It was replaced with a bunch of other chemicals that work as well as Freon did but aren't eco-hazardous.  (I wrote a report on this years ago, and it was surprising how quickly the chemical industry tackled this and came up with better chemicals.)

I'd be careful about solvents; most are bio-active in some way and many can cause brain/nerve damage.  WE could afford to install whatever safety equipment was needed to keep the stuff contained, but it would be difficult to duplicate that on a hobbyist scale. 

Probably the reason the solvent chamber was heated, was to cause the solvent to evaporate off the plastic uniformly and then cause the plastic to harden up more quickly.  This would be part of the solution to using the chemicals safely: evaporate them off, condense them back down, and reuse them as far as possible.   Can't do that in your oven (plus or minus fire/explosion risk). 


Back in the day, friends of mine used to do WE and AE and suchlike hard plastics by putting them through a restaurant dishwasher and then buffing on a wheel.  After the dishwasher, the housings looked spotless but dull.  After the buffing treatment, they looked new. 

So now we have the fading problem to contend with, and I'd suggest something like the following:

Step 1:  Soak in lukewarm water for an hour or two, this to loosen up stickers and aged dirt (then scrub off the sticker paper with a soft brush).

Step 2:  Dishwasher but NOT using high-temperature wash, rinse, or dry, which will warp soft plastics.  Use warm wash and warm rinse.  This may take checking the dishwasher periodically to be sure the cycle isn't going into high-temp mode. 

Step 3:  Dunk a tank of liquid RetroBrite bath per Kleenax's method, with UV lights above the chem tank.  (The ingredients in RetroBrite are all safe, but ventilation is always good.)  This of course is the bottleneck in the process, as you might only be able to do one phone's worth of plastics at a time.

Step 4:  Lukewarm water rinse.  Result at this point should be perfectly clean parts with the fading undone.   Then air-dry; a fan makes this go much faster (for those of us who have fans from the same eras as our phones, there's a certain symmetry about this:-)

Step 5:  Either or both of the commercial plastics-treatment compounds (darn if I can't remember the names: there are three or four different ones in a kit) and/or buffing on a wheel using fine white compound and a soft wheel at low to medium speed (electric drill useful for this). 

Best part is, with a bit of care, this won't result in logos and suchlike getting blurred or fuzzed out.  The result should end up looking like new, or with the "newer than new" shine that some folks prefer. 


My first "find" was a rotary WE with an ITT shell. The handset logo is exactly as described here. At first I thought it was painted but I couldn't find any evidence of paint. I wonder if they did handsets this way also?