Fixing a Distorted coiled Handset Cord.

[TelePlay]

I forgot to mention that I think the coiled cords were made by tightly winding a round cord around a metal rod.

The rod with the cord in place was electrically heated to a temperature that was just below the cords melting point, a temperature at which the cord touching the metal rod deformed  and when allowed to cool over time, the cord stayed coiled.

If you look at a coiled cord, the inside of the coil is totally flat (from the metal rod) and if you look between the coils, the side of coils is  flat near the inside of the coil, the side of the coil closest to the metal rod.

So, to create a coiled cord they heated the cord material from the inside to a point where the round cord "melted" and took on the shape of the hot, round rod - flat. The flat coil sides shows how much of the rounded cord was flattened.

They may not have heated the outside of the round cord and, in fact, heated the rod in a cold chamber to keep the outside of the soon to be coiled cord from deforming, to keep it round.

It would be fun to put a voltage across a metal rod having a resistance, say a NiChrom rod (I'd hate to see the price of 3 foot long 3/8" diameter nichrom rod), and using a Variac to heat such a rod with a distorted coiled cord wrapped around it to a specific temperature for a period of time to reform the distortion.

Then there's passing steam through a 3/8" pipe for a specific period of time to heat and thus reform a distorted coiled cord.

Might be other ways as well.

[TelePlay]

If anyone here wins this 1955 WE Mediterranean Blue on eBay,

https://www.ebay.com/itm/326027537038

I would be willing to recoil the handset cord, if not physically damaged, for free if the new owner pays for shipping both ways.

[artdecobuchwald]

Hello all and a happy new year to you.  I recently restored a Stromberg Carlson 1211.  I chose to keep the non-original, but period, handset cord.  It is coiled plastic.  I was not happy with how it looked after a clean-up, so searched and found this topic.  The first picture details the rather disheveled cord.  I read everyone's posts and decided I would wrap the cord on a 2 foot 3/8" diameter steel rod and put it in the oven at 200 degrees on the convection setting.  After 2-1/2 hours I took it out and put it in the near 0 Fahrenheit temps outside for about 5 hours.  After this I brought it inside to acclimate for another 5 hours. This process really made a difference in coil consistency and tightness.  You can see it hanging on the door.  I then proceeded to reverse the coils and take another picture of it hanging.  Not a huge difference, but significant.  Now it is back on the phone and I think it really makes a huge difference to the presentation.  Thanks to all whose experimentation went before my project.  It was really a flawless experience because of this forum!

[TelePlay]

Well done. Glad the forum could help.

Wall phones have to fight gravity, unfortunately, which defeats some of the restoration efforts. At least the coils are once again uniform.

I use an aluminum rod which seems to better transfer heat to the inside surface of the coils.

IIRC, phone manufacturers used to electrically heat the metal rod to create coils out of straight, round cord. Would take it up to near melting to form the coils. That's why the inside of the coils are flat and the inner sides of the coil show signs of the cord coils sticking together.

They must have used a metal rod with some resistance causing it to heat when a voltage was applied.

What you did is very good.

[artdecobuchwald]

Thanks, Teleplay.  Yes, aluminum is a great conductor of heat.  I would have used that had I not easily located the stainless rod.

Now the big question is, what phone to do next.  I always seem to have some contenders lying around vying for their chance...

Adam

[Jim Stettler]

IIRC, phone manufacturers used to electrically heat the metal rod to create coils out of straight, round cord. Would take it up to near melting to form the coils. That's why the inside of the coils are flat and the inner sides of the coil show signs of the cord coils sticking together.

They must have used a metal rod with some resistance causing it to heat when a voltage was applied.
WE used a 3/8" metal rod and baked them in an oven. Im pretty sure i have read the specifics in some old posts

What you did is very good.

WE used a 3/8" metal rod. and an oven .
electrically heating the rod was likely a later technique.
Ther are old posts regarding the techniques. likely searchable under recoiling cords is my best guess for topic.