1960s-1970s Telephone Repair

[J. B. Wood]

Hello, all, especially those with familiarity with subject. I've got a
decades-old Stromberg-Carlson SC-2554 wall mount phone. It's still in
great shape except recently a small white piece of plastic on the
make/break hook switch broke rendering the rest of the cradle mechanism
inoperative. The plastic piece finally broke from the tension from the
return spring. It's a clean break but I'm afraid that even if I can
glue the pieces back together it will most likely fail again in short
order. Thanks for your time and your comment is most appreciated.
Sincerely,
--
J. B. Wood e-mail: arl_123234@hotmail.com

 

There is a line of products of which Plastic-Weld is one that I have used with much success over the years for similar types of problems. This is a solvent based "glue" that actually dissolves the plastic a bit and reforms it. The joint essentially disappears. Caution though, don't press together too much or you will deform the plastic. Only apply enough pressure to be sure that the two parts meet firmly.

Dan

 

[Baron]

J. B. Wood prodded the keyboard with:

Hello, all, especially those with familiarity with subject. I've
got a decades-old Stromberg-Carlson SC-2554 wall mount phone. It's
still in great shape except recently a small white piece of plastic
on the make/break hook switch broke rendering the rest of the cradle
mechanism inoperative. The plastic piece finally broke from the
tension from the return spring. It's a clean break but I'm afraid
that even if I can glue the pieces back together it will most likely
fail again in short order. Thanks for your time and your comment is
most appreciated.
Sincerely,

You could always try a steel pin heated hot enough to sink into the
plastic, a bit like a staple, or cross drill it and press a staple in
the holes.

--
Best Regards:
Baron.

 

[Jeff Liebermann]

On Sun, 10 Apr 2016 16:12:40 -0400, "J. B. Wood"
<john.wood@nrl.navy.mil> wrote:

Hello, all, especially those with familiarity with subject. I've got a
decades-old Stromberg-Carlson SC-2554 wall mount phone. It's still in
great shape except recently a small white piece of plastic on the
make/break hook switch broke rendering the rest of the cradle mechanism
inoperative. The plastic piece finally broke from the tension from the
return spring. It's a clean break but I'm afraid that even if I can
glue the pieces back together it will most likely fail again in short
order. Thanks for your time and your comment is most appreciated.
Sincerely,

Glue the broken parts back together but do NOT reinstall them in the
phone. Instead, find someone with a 3D digitizer and 3D printer who
can make a reproduction of the original. I'm not familiar with SC
phones, but the equivalent part in a Western Electric wall phone is a
flat plate with two rectangular holes. That can probably be machined
out of plastic. I couldn't find a photo with Google Images.

Are you sure about the model number? The SC number was SC-554 while
the WE number was 2554.

SC-554:
<https://www.youtube.com/watch?v=cDP6I8bEP8o>

WE 2554:
<https://www.youtube.com/watch?v=VedsBJfsLlo>


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[pfjw@aol.com]

On Sunday, April 10, 2016 at 4:12:44 PM UTC-4, J. B. Wood wrote:

Hello, all, especially those with familiarity with subject. I've got a
decades-old Stromberg-Carlson SC-2554 wall mount phone. It's still in
great shape except recently a small white piece of plastic on the
make/break hook switch broke rendering the rest of the cradle mechanism
inoperative. The plastic piece finally broke from the tension from the
return spring. It's a clean break but I'm afraid that even if I can
glue the pieces back together it will most likely fail again in short
order. Thanks for your time and your comment is most appreciated.
Sincerely,
--
J. B. Wood e-mail: arl_123234@hotmail.com

Mpfffff... take out the part. Put it back together with JB Weld - available everywhere. Be sloppy with the material, but make sure that you do not glue the part to anything else. I will on occasion tie such a part together with fine thread (if there are holes through it, even better) and suspend it during the curing process. Then with files, X-Acto and sandpaper, reshape the part to its correct size, removing flash and sprue, so to write. Re-drill any filled holes and you are done. JB Weld will be harder and stronger than the OEM plastic by a considerable margin.

Peter Wieck
Melrose Park, PA

 

[pfjw@aol.com]

On Monday, April 11, 2016 at 9:22:11 AM UTC-4, Chuck wrote:

On Sun, 10 Apr 2016 16:12:40 -0400, "J. B. Wood"


I have had good luck with some plastic parts using Gorilla super glue.

In most cases, I would suggest super glue - Gorilla or otherwise. But many phone parts are made from DelrinŽ (Polyoxymethylene), which also happens to be one of the materials used to deliver super-glue as it does not stick to Delrin. I am not stating that this particular part is Delrin - but a great many friction and contactor parts are made from that material because of its self-lubricating and excellent insulating properties. Further to this, it naturally repels metallic dust and powder, such as could build up and arc.

JB Weld *does* stick to Delrin reasonably well, and has enough self-integrity to bridge and fill.

Peter Wieck
Melrose Park, PA

 

The product I am referencing is NOT JB-Weld. The product is made by Plastruct and is called Plastic Weld. It is a clear liquid not an epoxy that actually dissolves the plastic and allows for reformation. It is considered a plastic solvent and cement.

Dan

 

[pfjw@aol.com]

On Monday, April 11, 2016 at 10:30:40 AM UTC-4, dansabr...@yahoo.com wrote:

The product I am referencing is NOT JB-Weld. The product is made by Plastruct and is called Plastic Weld. It is a clear liquid not an epoxy that actually dissolves the plastic and allows for reformation. It is considered a plastic solvent and cement.

Dan

Dan:

If that part *is* Delrin, it will be entirely impervious to Plastic Weld. As will be many high density, self-lubricating plastics.

The material you suggest is useful on the polystyrene/acrylic based materials, not so much on others.

Peter Wieck
Melrose Park, PA

 

[Don Y]

On 4/10/2016 1:12 PM, J. B. Wood wrote:

Hello, all, especially those with familiarity with subject. I've got a
decades-old Stromberg-Carlson SC-2554 wall mount phone. It's still in great
shape except recently a small white piece of plastic on the make/break hook
switch broke rendering the rest of the cradle mechanism inoperative. The
plastic piece finally broke from the tension from the return spring. It's a
clean break but I'm afraid that even if I can glue the pieces back together it
will most likely fail again in short order. Thanks for your time and your
comment is most appreciated. Sincerely,

Your description is vague.

Is the plastic piece part of the housing? Or, a mechanical actuator that
conveys the hookswitch's state to the actual switch?

Said another way, does the phone *appear* (visually) to be intact -- but,
some INTERNAL mechanism is broken that allows it to FUNCTION as it should?

(Could you, perhaps, post a picture on a hosting site with a link, here?)

 

[J. B. Wood]

On 04/10/2016 04:42 PM, Jeff Liebermann wrote:

Are you sure about the model number? The SC number was SC-554 while
the WE number was 2554.

SC-554:
https://www.youtube.com/watch?v=cDP6I8bEP8o

WE 2554:
https://www.youtube.com/watch?v=VedsBJfsLlo

Thanks for the response, Jeff. The number stamped on the back of the
instrument is S-C 2554BPM. Perhaps the "2" designated a DTMF type dial?
Sincerely,
--
J. B. Wood e-mail: arl_123234@hotmail.com

 

[J. B. Wood]

On 04/10/2016 06:25 PM, dansabrservices@yahoo.com wrote:

There is a line of products of which Plastic-Weld is one that I have
used with much success over the years for similar types of problems.
This is a solvent based "glue" that actually dissolves the plastic a
bit and reforms it. The joint essentially disappears. Caution
though, don't press together too much or you will deform the plastic.
Only apply enough pressure to be sure that the two parts meet
firmly.

Dan

Thanks for the follow-up, Dan. Are you referring to one of the products
from http://www.jbweld.com/collections/plastic-composite-pvc?

If so, is there a specific one from this company that you can recommend?
Thanks. Sincerely,

--
J. B. Wood e-mail: arl_123234@hotmail.com

 

[J. B. Wood]

On 04/11/2016 07:13 AM, Don Y wrote:

Your description is vague.

Is the plastic piece part of the housing? Or, a mechanical actuator that
conveys the hookswitch's state to the actual switch?

Said another way, does the phone *appear* (visually) to be intact -- but,
some INTERNAL mechanism is broken that allows it to FUNCTION as it should?

(Could you, perhaps, post a picture on a hosting site with a link, here?)

Hello, and yeah, I kind of figured that might be a problem. It's just a
small piece of plastic that separates the electrical contacts on the
hook switch. A small shaft which passes through the plastic piece upon
which a spring-loaded bracket pivots. This bracket makes contact with
the arm that determines whether the handset is on or off the cradle.
The plastic split right where that small shaft passes. Sincerely,
--
J. B. Wood e-mail: arl_123234@hotmail.com

 

[Chuck]

On Sun, 10 Apr 2016 16:12:40 -0400, "J. B. Wood"
<john.wood@nrl.navy.mil> wrote:

Hello, all, especially those with familiarity with subject. I've got a
decades-old Stromberg-Carlson SC-2554 wall mount phone. It's still in
great shape except recently a small white piece of plastic on the
make/break hook switch broke rendering the rest of the cradle mechanism
inoperative. The plastic piece finally broke from the tension from the
return spring. It's a clean break but I'm afraid that even if I can
glue the pieces back together it will most likely fail again in short
order. Thanks for your time and your comment is most appreciated.
Sincerely,

I have had good luck with some plastic parts using Gorilla super glue.

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[Jeff Liebermann]

On Mon, 11 Apr 2016 07:23:49 -0400, "J. B. Wood"
<john.wood@nrl.navy.mil> wrote:

On 04/10/2016 04:42 PM, Jeff Liebermann wrote:

Are you sure about the model number? The SC number was SC-554 while
the WE number was 2554.

SC-554:
https://www.youtube.com/watch?v=cDP6I8bEP8o

WE 2554:
https://www.youtube.com/watch?v=VedsBJfsLlo

Thanks for the response, Jeff. The number stamped on the back of the
instrument is S-C 2554BPM. Perhaps the "2" designated a DTMF type dial?
Sincerely,

Ah, that's a better number. There's one for sale on eBay if you need
parts:
<www.ebay.com/itm/STROMBERG-CARLSON-2554-BPM-Wall-Mounted-Single-Line-Corded-Phone-/281979044418>

It's impossible to get into a discussion on adhesives without everyone
recommending their favorite potions, concoctions, and methods. I'll
just make things worse.

My guess(tm) is that the plastic in the phone is probably ABS (acrylic
butyl styrene) which will weld nicely with acetone solvent. There are
overpriced potions available that are mostly acetone, but might
include other solvents (MEK, toluene, etc).
<http://nerfhaven.com/forums/topic/18527-intro-to-solvent-welding-plastic/>

Superglue (cyanoacrylate) is too brittle and mutilates acrylics.
<http://info.craftechind.com/blog/bid/323475/Stick-to-it-A-Guide-to-the-Best-Glue-for-Plastic>

Urethane adhesives, such as Gorilla Glue, don't do well with many
plastics because they do NOT contain any solvents. Fortunately, the
phone switch insulator (or whatever it's called) sees force in only
one direction, so marginal adhesives will probably work, for a while.

Just to muddy the waters, I've been learning plastic welding using
some home made brass nozzles attached to my SMT desoldering station
hot air gun. When it works, it works great. When I do something
wrong, it destroys the part. Plastic welding works best for me on
large plastic parts, and not so good on small plastic parts.

I'm also a fan of hot melt glue, but that's not appropriate for this
job. However, if you do decide to try hot melt glue, be sure to get
the correct type of adhesive stick:
<https://en.wikipedia.org/wiki/Hot-melt_adhesive>

Good luck.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jeff Liebermann]

On Mon, 11 Apr 2016 07:30:34 -0700 (PDT), dansabrservices@yahoo.com
wrote:

The product I am referencing is NOT JB-Weld. The product is made
by Plastruct and is called Plastic Weld. It is a clear liquid
not an epoxy that actually dissolves the plastic and allows for
reformation. It is considered a plastic solvent and cement.
Dan

A URL is amazingly helpful:
<http://www.amazon.com/Plastruct-Plastic-Weld-applicator-2oz/dp/B00FDFWJD8>
The MSDS at:
<http://plastruct.com/wp-content/uploads/2015/06/MSDS_PPC_2.pdf>
says that it's:
Methylene Chloride (Dichloromethane) 80-90%
Methyl Ethyl Ketone (MEK) 5-15%
Yep, that will certainly work for ABS, PVC, and various styrene
plastics.

However, methyl chloride is rather dangerous. The EU banned the stuff
in 2011. It was commonly used for furniture stripper before it was
recognized as hazardous:
<https://www.cdph.ca.gov/programs/hesis/Documents/MethyleneChlorideAlert.pdf>
Suggestion: Use the stuff outdoors and wear the usual protection
(breather, glasses, gloves, etc).

Plastruct video:
<https://www.youtube.com/watch?v=979eXts6DwM> (1:23)


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

On Sun, 10 Apr 2016 16:12:40 -0400, "J. B. Wood"
<john.wood@nrl.navy.mil> wrote:

Hello, all, especially those with familiarity with subject. I've got a
decades-old Stromberg-Carlson SC-2554 wall mount phone. It's still in
great shape except recently a small white piece of plastic on the
make/break hook switch broke rendering the rest of the cradle mechanism
inoperative. The plastic piece finally broke from the tension from the
return spring. It's a clean break but I'm afraid that even if I can
glue the pieces back together it will most likely fail again in short
order. Thanks for your time and your comment is most appreciated.
Sincerely,

I don't know what kind of plastic your part is but there is a two part
plastic cement that bonds well to many of the plastics that are hard
to glue. I don't remember the name but I think it is made by Loctite
which has lots of epoxies and the like at hardware stores. Anyway, the
stuff is made specifically for plastic repair, not general repair jobs
like JB Weld (which is pretty good stuff) and 5 minute epoxy and the
like. I have used the stuff and it worked very well. Smelled bad when
curing but no smell once cured. I even used it in a test repair. The
radiator in our Toyota Camry developed a crack in the upper plastic
part of the radiator. I ordered a new radiator and while waiting for
it tried this plastic repair stuff. I cleaned and roughed up the
plastic, slathered on the glue, then I laid a piece of cloth which was
saturated with the glue on top. After it set the car was driven for a
couple weeks before I replaced the radiator. The patch never gave up
and the radiator got hotter than the recommended highest temperature
for the glue. I don't know how long the patch would have lasted but
since it was on the car I installed the new radiator.
Eric

 

[Phil Hobbs]

On 04/11/2016 12:22 PM, Jeff Liebermann wrote:

On Mon, 11 Apr 2016 07:30:34 -0700 (PDT), dansabrservices@yahoo.com
wrote:

The product I am referencing is NOT JB-Weld. The product is made
by Plastruct and is called Plastic Weld. It is a clear liquid
not an epoxy that actually dissolves the plastic and allows for
reformation. It is considered a plastic solvent and cement.
Dan

A URL is amazingly helpful:
http://www.amazon.com/Plastruct-Plastic-Weld-applicator-2oz/dp/B00FDFWJD8
The MSDS at:
http://plastruct.com/wp-content/uploads/2015/06/MSDS_PPC_2.pdf
says that it's:
Methylene Chloride (Dichloromethane) 80-90%
Methyl Ethyl Ketone (MEK) 5-15%
Yep, that will certainly work for ABS, PVC, and various styrene
plastics.

However, methyl chloride is rather dangerous. The EU banned the stuff
in 2011. It was commonly used for furniture stripper before it was
recognized as hazardous:
https://www.cdph.ca.gov/programs/hesis/Documents/MethyleneChlorideAlert.pdf
Suggestion: Use the stuff outdoors and wear the usual protection
(breather, glasses, gloves, etc).

Plastruct video:
https://www.youtube.com/watch?v=979eXts6DwM> (1:23)

Methyl chloride (CH3Cl) != methylene chloride (CH3Cl2). The stuff with
the shorter name is pretty evil, but the longer stuff you can
practically drink. (Just joking, kids. Don't drink paint remover.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

[Phil Hobbs]

On 04/11/2016 02:03 PM, Phil Hobbs wrote:

On 04/11/2016 12:22 PM, Jeff Liebermann wrote:
On Mon, 11 Apr 2016 07:30:34 -0700 (PDT), dansabrservices@yahoo.com
wrote:

The product I am referencing is NOT JB-Weld. The product is made
by Plastruct and is called Plastic Weld. It is a clear liquid
not an epoxy that actually dissolves the plastic and allows for
reformation. It is considered a plastic solvent and cement.
Dan

A URL is amazingly helpful:
http://www.amazon.com/Plastruct-Plastic-Weld-applicator-2oz/dp/B00FDFWJD8
The MSDS at:
http://plastruct.com/wp-content/uploads/2015/06/MSDS_PPC_2.pdf
says that it's:
Methylene Chloride (Dichloromethane) 80-90%
Methyl Ethyl Ketone (MEK) 5-15%
Yep, that will certainly work for ABS, PVC, and various styrene
plastics.

However, methyl chloride is rather dangerous. The EU banned the stuff
in 2011. It was commonly used for furniture stripper before it was
recognized as hazardous:
https://www.cdph.ca.gov/programs/hesis/Documents/MethyleneChlorideAlert.pdf
Suggestion: Use the stuff outdoors and wear the usual protection
(breather, glasses, gloves, etc).

Plastruct video:
https://www.youtube.com/watch?v=979eXts6DwM> (1:23)


Methyl chloride (CH3Cl) != methylene chloride (CH3Cl2). The stuff with
the shorter name is pretty evil, but the longer stuff you can
practically drink. (Just joking, kids. Don't drink paint remover.)

Cheers

Phil Hobbs

CH2Cl2.

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

[Jeff Liebermann]

On Mon, 11 Apr 2016 09:51:46 -0700, etpm@whidbey.com wrote:

I don't know what kind of plastic your part is but there is a two part
plastic cement that bonds well to many of the plastics that are hard
to glue. I don't remember the name but I think it is made by Loctite

<http://www.loctiteproducts.com/p/sg_plstc/overview/Loctite-Plastics-Bonding-System.htm>

Cyanoacrylate resin and MEK as "activator". Works quickly and great
for most plastics. However, the MEK tends to dry out prematurely in
the bottle. Have some extra MEK handy if you're going to use it.
Also, make sure everything is free of grease or it won't stick.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jeff Liebermann]

On Mon, 11 Apr 2016 14:03:54 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

Methyl chloride (CH3Cl) != methylene chloride (CH3Cl2). The stuff with
the shorter name is pretty evil, but the longer stuff you can
practically drink. (Just joking, kids. Don't drink paint remover.)

Oops. Thanks for the correction. I thought they were the same stuff.

>Cheers

Grumble...
Jeff L.

>Phil Hobbs
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558