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Soft plastic WE 554 housing damaged/discolored by isopropyl alcohol

Started by MaximRecoil, August 28, 2012, 06:45:59 AM

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MaximRecoil



This was my fault. I never knew about Tenite / soft plastic before coming to this forum, and I've always cleaned plastic items with rubbing alcohol without issue, including various WE rotary phones. I'd even cleaned the handset of the phone that this housing goes with many times with alcohol (it is ABS obviously). Rubbing alcohol comes in a plastic bottle even.

So anyway, I started cleaning this housing with alcohol and a toothbrush and I noticed immediately that it was dissolving something. At first I thought it must be paint, but then it became obvious that the plastic itself was being dissolved. I thought this was highly strange, because like I said, I'd never encountered plastic before that was not impervious to alcohol. An internet search then informed me about Tenite / soft plastic and it's vulnerability to alcohol.

I was irritated with myself, but it wasn't really a great loss. This 1957 housing was part of a "frankenphone" (1960 Northern Electric 593 phone with a 1968 Kellogg dial) and had been modularized (as well as cracked in the corner of the modular notch in the process, which I'd fixed with super glue) when I got it a dozen years ago.

So I decided this would be a good guinea pig for trying to fix/polish (something I'd never tried before). I wet-sanded the entire housing with 400-grit sandpaper, and the alcohol damage disappeared almost immediately. Then I used 600-grit, and finally I rubbed it with toothpaste and an old holey sock for about 10 or 15 minutes:



The toothpaste gave it a nice satin sheen, and it could probably be improved if I were to work at it longer. However, I have some Novus 2 coming in the mail, so I'll wait for that to see if I can get it shinier. As a side-note, the housing has a "minty-fresh" smell now that won't go away, even though I washed the toothpaste off with soap and water, but I'm not concerned about that (plus it will probably go away once I have at it with the Novus).

twocvbloke

Quote from: MaximRecoil on August 28, 2012, 06:45:59 AMAs a side-note, the housing has a "minty-fresh" smell now that won't go away

If you've not smelled tenite handsets yet, then be thankful, the smell that Tenite releases is akin to rancid, sweaty, cheesy feet, the shells lose the scent, but the handsets tend to hold onto that smell, so, minty fresh would be a good replacement...  :D

AE40FAN

I destroyed a handset with isopropyl alcohol and it was from the 1970s (Same outcome as you).  I don't have a clue as to how you had success with cleaning plastic using this method?

MaximRecoil

Quote from: AE40FAN on August 28, 2012, 08:40:16 AMI don't have a clue as to how you had success with cleaning plastic using this method?

The damage from the alcohol wasn't very deep, so the 400-grit sandpaper quickly removed it, exposing the undamaged plastic beneath. The 600-grit smoothed it out even more, but it still looked rather rough. The toothpaste brought back some shine to it, but I think I can get a better shine when the Novus 2 arrives. The whole process didn't take long. Either way, it looks a lot better now than it did with the alcohol damage.

Edit: Or did you mean you don't have a clue how I've had success with cleaning plastic using alcohol? If so, I have yet to encounter any plastic in a consumer device (the Tenite housing in this thread being the sole exception) that reacts to isopropyl alcohol in any way.

jsowers

That housing looks like it's from a 593 instead of a 554. It doesn't have "Bell System" on it. The 593 housings were missing those words because they were sold to independent telcos.

You did a great job with the refinishing. I was going to suggest Novus 2 might clear that up all by itself. It works wonders. You'll like it.

I've used denatured alcohol on hundreds of hard plastic housings with no ill effects and it actually cleans them better than anything else I've ever tried and leaves them shiny and with no residue. But alcohol and soft plastic do not mix!
Jonathan

twocvbloke

Quote from: jsowers on August 28, 2012, 04:53:04 PM
That housing looks like it's from a 593 instead of a 554. It doesn't have "Bell System" on it. The 593 housings were missing those words because they were sold to independent telcos.

The phone's already been ID'd:
http://www.classicrotaryphones.com/forum/index.php?topic=7502.0

:)

MaximRecoil

Quote from: jsowers on August 28, 2012, 04:53:04 PM
That housing looks like it's from a 593 instead of a 554. It doesn't have "Bell System" on it. The 593 housings were missing those words because they were sold to independent telcos.

Interesting. So it's a 1957 Western Electric 593 housing mated to a 1960 Northern Electric 593 phone.

QuoteYou did a great job with the refinishing. I was going to suggest Novus 2 might clear that up all by itself. It works wonders. You'll like it.

It might have, but in the worst spot (upper right-hand corner) where I first started with the toothbrush dripping with alcohol, there were grooves melted into the plastic from the bristles, and I had to sand that area a little extra to clear it up. I don't know if a polish for fine scratches could have taken out those grooves, but it probably could have taken care of the rest of the damaged areas, because they weren't as bad. I'm looking forward to trying it. I've been meaning to buy some for a long time, because it is commonly used in another one of my hobbies as well: coin-operated video arcade machines, i.e., polishing their plexiglass bezels. They usually use all three stages for that though (Novus 3, 2, and 1).   

QuoteI've used denatured alcohol on hundreds of hard plastic housings with no ill effects and it actually cleans them better than anything else I've ever tried and leaves them shiny and with no residue. But alcohol and soft plastic do not mix!

I've never had any issues with using isopropyl alcohol (never tried denatured alcohol) on the common types of plastic that you find on items produced in the past ~50 years or so, such as ABS, nylon, plexiglass, and Lexan (thin Lexan was commonly used for control panel overlays on arcade machines, and plexiglass was commonly used for their bezels, and I've cleaned those things countless times with alcohol). Here's a post I came across on the topic when I was trying to find out why my housing reacted to the alcohol:

QuoteHi Robert,

I found your question a little puzzling. As an engineer with years of experience with a wide range of plastics, I have never once run across any recommendation to use amyl alcohol for cleaning purposes. For many plastics such as nylon, polyester, ABS, and especially solvent- sensitive polycarbonate (Lexan), isopropyl alcohol is recommended for cleaning purposes. In fact, because of polycarbonate's high solvent sensitivity, the only universally recommended cleaning solvent for this plastic is isopropyl alcohol.

The main difference between n-amyl and isopropyl alcohols (in this context) is the length of the hydrocarbon "backbone". N-amyl alcohol's carbon chain is 5 carbon atoms long, whereas isopropyl alcohol's carbon chain is only 3 carbons atoms long. The result is that isopropyl alcohol is more volatile and therefore evaporates faster after it is used for cleaning.

Neither of these alcohols "dries out" plastic, since there is no water (or any other substance) in plastic to "dry out" in the first place. Both of these alcohols act as both polar and non-aggressive non-polar solvents, which is very advantageous for cleaning. Acting as polar solvents, they are able to dissolve polar contaminants such as salts, and other water soluble contaminants.

Both of these alcohols are also able to dissolve non-polar contaminants such as oils and greases, with isopropyl alcohol acting as a somewhat more aggressive non-polar solvent because of its shorter carbon "backbone" and therefore lower molecular weight. Unlike many hydrocarbon solvents, neither of the two alcohols are damaging to any common plastics.

To summarize, when comparing the two, isopropyl alcohol is the cleaning solvent of choice for most plastics. Unlike normal-amyl alcohol, which is not easily available, 99% isopropyl alcohol is available at any drugstore. Isopropyl is better at removing oily deposits, and dries faster after use.

Regards,
Bob Wilson

link

Quote from: twocvbloke on August 28, 2012, 05:29:46 PM
Quote from: jsowers on August 28, 2012, 04:53:04 PM
That housing looks like it's from a 593 instead of a 554. It doesn't have "Bell System" on it. The 593 housings were missing those words because they were sold to independent telcos.

The phone's already been ID'd:
http://www.classicrotaryphones.com/forum/index.php?topic=7502.0

:)

Yes, the phone was ID'd (as a Northern Electric 593), but the housing wasn't ID'd until this thread. I assumed it was a 554 housing, so I never asked about it. I didn't know it would have had "Bell System" on it if it was a 554. I thought the lack of "Bell System" on it was simply because it was much older than my other two 554s (which do say "Bell System").

poplar1

I don't have a NE or Graybar (WE) catalog handy, but my guess is that both the 554 and 593 were offered for sale to the independents as well as both 500 and 591 desk sets.
"C'est pas une restauration, c'est une rénovation."--François Martin.

DavePEI

Quote from: jsowers on August 28, 2012, 04:53:04 PM
That housing looks like it's from a 593 instead of a 554. It doesn't have "Bell System" on it. The 593 housings were missing those words because they were sold to independent telcos.
NE 554s were also sold to the independents and had normal NE markings. The days of NE not selling Bell style phones to independents ended with the 302/Uniphones.

That might not have been the case with WE, but definitely NE sold to both.

I have tons of true 554s and 500s with NE markings distributed through Island Tel and NB Tel. Prior to then, NE sold 302s to only Bell Companies and Uniphones to only independents.

Just an interesting note.

Dave
The Telephone Museum of Prince Edward Island:
http://www.islandregister.com/phones/museum.html
Free Admission - Call (902) 651-2762 to arrange a visit!
C*NET 1-651-0001

Bill

Not meaning to hijack the thread, but it occurred to me that the effect you see might be viewed as a helpful tool in some cases, rather than a problem. In particular, a deep gouge might be filled and smoothed over in prep for final sanding.

I'm thinking, of course, about Chuck Hensley's threads on solvent-polishing hard plastic.

http://www.classicrotaryphones.com/forum/index.php?topic=5239.0
http://www.classicrotaryphones.com/forum/index.php?topic=5260.0

Bill

MaximRecoil

Wow, Novus 2 is amazing stuff:



I might go over it again a time or two, but it really looks good right now. You'd never know it'd been damaged by alcohol recently.