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Fixing a Distorted coiled Handset Cord.

Started by Dan/Panther, October 17, 2008, 12:20:15 AM

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Dennis Markham

OK guys, I'm giving this a try.  I've never tried to tighten a cord.  I've read your postings a couple of times.  I'm using the oven method as opposed to hot water. 

I have a wall phone cord (model 554 from October of 1964) that I want to reuse.  It is a nice cord except it is a bit stretched at each end.  Because I can't throw ANYTHING away I have lots of stretched-out cords.  So I'm starting with one of those.

For my example I am using a very long stretched red handset cord.  I'm sure it was originally on a wall phone.  I'm guessing that the phone may have been in some type of automotive environment as it was very greasy and stretched.  I'm guessing that it was stretched to six or seven feet.

I bought a 3/8th inch wooden dowel for this experiment.  I took the red handset cord and soaked it in warm soapy water for about 45 minutes.  I drained the water off and then used a 409 type cleaner and a rag to clean each coil.  It's nice and clean.  I then wrapped the cord tight on the dowel and fastened each end per Dan/Panther's instructions.  To keep it off the floor of the oven, or from touching the walls of the oven I took two small pieces of wood (cut off the end of a 2X4 and cut in half again) and drilled holes in each, just larger than the 3/8 inch dowel. 

The dowel is almost too long to fit in the oven.  So my experiment nearly ended before I started.  But I was able to kind of put it in the oven on an angle with one jammed up tight near the roof of the oven.  Before placing it in the oven I wrapped the four leads on each end with foil to keep them from touching anything.  Whether or not it will protect them we will see.

I have the oven set at about 225 degrees.  It's baking now.  In a few hours I'll take it out and put it on the back porch.  Since our temps are going to be zero tonight (currently about ten degrees above) that ought to be better than sticking it in the freezer.

More to come...................

mienaichizu

I'd like to try it too but would it not melt inside the oven?

Dennis Markham

It's been in the oven now for about two hours.  I can smell the plastic but it doesn't appear to be melting.  In another 20 minutes it's headed out into the cold Michigan winter night.

Dennis Markham

#18
Part One of this "experiment" is concluded.  I may have rushed things a bit but I had to see if I was wasting my time with this cord.  There are couple of factors about this cord that made it probably not the best choice for my first experiment.  The first is the length of the cord.  This cord, tightly coiled is a long cord.  They tend to "hang long" when on the handset and the handset is in the cradle of the 554.  It's a heavy cord. Secondly it was in the poorest of condition.  Not only was it stretched but the cord had stiffened.  I could almost stand it up in the corner! (Bad cord!)  :)

After two hours in the oven at about 230 degrees it sat outside for 13 hours in near zero temperatures.  I brought it in this morning and used my trusty hair dryer to warm it before trying to remove it from the dowel.  (I love that hair dryer!)  The faint odor I was smelling last night I think was the tape not the cord.  There was no evidence of any damage to the cord as a result of the heat.  The cord was stuck to the dowel in that I had to run my finger nail from one end to the next....like a needle in the groove of a record (you old people like me relate to this) to get the cord off without pulling it off the stick.

Result:  The cord was no longer stiff.  The coils maintained their original shape.  However they are NOT tight enough.  The cord is usable but as I held it up to my 554 holding one end where it would attach to the phone and the other where it would attach to the handset there was some sag, or stretching.  However it didn't hang as low as the cord on my wall phone.  That cord when installed was new old stock and it's been hanging there for a year or so.  So gravity is going to work on that.

Conclusion:  Would I be satisfied with that cord on a nice soft plastic wall phone?  No.  Is it much improved from when the little experiment began?  Yes.  I would say it is 75% improved.  In a desk set situation where the cord lays on the table when not in use it may all for the repaired cord to be usable.

I am not going to give up on this cord yet.  I'd like to give it another shot but maybe this time use the hot water treatment on it.  Also I am in the process of doing a second cord.  This time I'm using a black handset cord which is the normal desk set length.  It is stretched but nothing like this red one.  I'll use a shorter dowel and bake it a bit longer and then it will be outside to watch the snow fall.

I'm attaching a photo of the cord after being removed from the dowel and after I manhandled it a bit.  I'm going to put the first photo on again so it is easier to compare the two.  We may be onto something here.  I know it's nothing that hasn't been done before.   But I've always looked for replacement cords which is great if you can get one but this may be helpful.  By the way, the red cord has a date of 1975 on the strain relief hook.

bingster

#19
I think that's a great set of posts, Dennis.  Well explained and well photographed.   The thing I find most interesting is that the process cured the cord of it's stiffness.  That can come in very handy even for cords that are not stretched or kinked, but which have just grown stiff over time.
= DARRIN =



Dennis Markham

#20
Bingster, thank you for the compliment on my "experiment".  Good point on the stiffness issue.   I have been working on the red cord again.  I put it back on the stick and strapped it down tightly.  This time I had the tea kettle and a large pot boiling water at the same time.  I must have filled up each about 4-6 times and poured the water slower over the coils.  I had the ends of the stick on each side of the kitchen sink with the cord coils suspended so there would be no flat spots.  I gave that cord a good soaking with the boiling water and now it's out in the cold again.  We'll see if it improves any.

Meanwhile I did a shorter cord from a model 500.  This one was stretched and a bit stiff.  I washed it like before, then wiped each individual coil using 409 cleaner to make it nice and clean.  In the oven between 225 & 250 degrees for several hours.  In fact I had it in the oven for about an hour and a half and had to leave.  So I turned off the oven and turned it back on again when I returned and left it in there for another 3 hours.  It's outside enjoying the frigid cold now.  Supposed to go down to -3 tonight.   We shall see how that one turns out.  I am more optimistic in that it wasn't as stretched and it's shorter.  It's from 1959. 

McHeath

My wife looked at the red cord before and after and said, and I quote, "Wow, it's like a miracle."

So I think you are doing pretty good work.  I assume that the plastic is reflowing to some degree in the heat, and then being reset, do you know how they made these cords?  (or still make them?)

Dennis Markham

I've done the second test on the red cord and did a black one as well.  First I will talk about the red one and show a couple of photos.  I will post results of the black in a separate posting so I can put on more photos.

I think that the condition of the red cord improved somewhat.  The cord is useable but again, since it is a wall phone cord as it hangs it is going to stretch.  Gravity is stronger than the strength of the coils.  Overall, I would increase the total improvement to 85%...maybe even 100% because before the cord was completely unusable.  The cord is now soft and pliable.

This time I poured boiling water over the cord while it was on the dowel.  A LOT of boiling water.  Would it have been better had it been able to soak in the water?  Perhaps.  I was thinking maybe a wall paper tray or something like that will work for soaking in boiling water or just below the boiling temperature.  The wallpaper trays I've seen were plastic so I don't know if they would support boiling water.  Just a thought.

After the water treatment it went outside for 24 hours.  Our morning temperature was below zero this morning so I guess that's cold enough.  A regular home freezer?  Maybe keep it in there longer.  What is long enough?

I took the second batch of photos after the cord had warmed to room temperature.    This cord is date stamped 1974.

I don't know if these second set of photos will show much more than the first "after" photos.

Dennis Markham

Now the black cord.  This cord is dated 1959.  It too was very stiff and stretched.  I put it on a shorter dowel and was able to fit it comfortably in the oven.  Again, I used little blocks with holes drilled to fit over the dowel at each end.  It kept the dowel suspended above the floor of the oven rack.  I put a couple of sheet pans down first so the blocks wouldn't fall through the grate.

I baked the cord for a longer period of time...probably all together 3-4 hours at 250 degrees.  Then it went out in near zero temperature for about 14 hours.  Some of that time the temperature was below zero.

The plastic seems different than that of the cord from 1974.  It is more sticky.  Long after it had warmed to room temperature I removed it from the dowel.  The coils stayed together and as the red one, it is soft and pliable.

I simulated conversation by holding each end the approximate distance one would stretch a cord from a desk phone to the ear and held it for a period of time, maybe a minute.  The cord did not immediately retract.  My photos will show the cord just off the dowel, immediately after simulated use and then a minute or two later as the coils kind of crept back together again.  If I "help" it, it will retract completely.

So once again it is usable where before it was not.  As the collectors like to say, "It Presents Well".  I have no immediate plans to do this one again use the water technique but may eventually (I've got other things to do!) do that. 

I think that in summation these techniques will greatly improve the condition of a useless, stiff and stretched cord, especially for display purposes.

I think the differences in plastic technology from 1959 to 1974 is evident in the feel of the cord.

Let me know if there are questions.  I may have omitted something.

Steve


I think it may be worth doing for a cord not easily replaced, or when wanting to keep a phone all original. they look in the pictures, to be much improved. with the red one, it looks like it should get tossed out in the before pics, but I think it looks usable in the after. not a new cord by any means, but very presentable. thanks for sharing the photos, I have an original black cord on a 57 desk I may try this on. it is still in fairly good shape, but may give better results as it's in better shape to start with.   
If you're a long way from home,
Can't sleep at night.
Grab your telephone,
Something just ain't right.

Dan/Panther

Dennis;
I would say both of the experimenrts were successful.
They both appear as N.O.S.
D/P

The More People I meet, The More I Love, and MISS My Dog.  Dan Robinson

Dennis Markham

Thanks Dan.  They are much improved for sure.  That black cord is 50 years old this year!  A half a century!  I'll bet the person(s) that made that cord never dreamed that someone in the 21st Century would be trying to make it look new again and posting pictures on the internet!  :)

Sargeguy

Now how about straight handset cords that curl up?  I have a vintage 302 with a straight rubber cord that thinks its a rattlesnake.  Should I just boil it and hang it out in the cold off a hook with handset attched? ???
Greg Sargeant
Providence, RI
TCI /ATCA #4409

Dan/Panther

Quote from: Sargeguy on January 18, 2009, 12:47:39 AM
Now how about straight handset cords that curl up?  I have a vintage 302 with a straight rubber cord that thinks its a rattlesnake.  Should I just boil it and hang it out in the cold off a hook with handset attched? ???

On straight cords I fastened them to a board by the strain reliefs, rather tightly. let them cool that way, and they stayed straight or if I coiled them up they would remain subtle, without twisting.  I make a loop of the cord when I hang up, and try to hang them up the same each time. This prevents the kinking from years of twisting.
Periodically I will hang the handset at length, to let it reach it's own comfort zone. this take out the minor twists.

D/P

The More People I meet, The More I Love, and MISS My Dog.  Dan Robinson

Sargeguy

Thanks!  I boiled it for a few then let it hang outside from the strain relief with the handset on the other end.  It's not exactly supple but at least its straight.
Greg Sargeant
Providence, RI
TCI /ATCA #4409