Re-forming Cloth Covered Coiled Handset Cord With Rubber Insulated Conductors

[gands-antiques]

Okay, I'll rewind it in the correct direction and I'll try hot water this time.


Thanks,
Gary

[Jim Stettler]

I heard some tips at a phone show over the weekend. To bake the cord coil:

Coil your cord on a 3/8" dowel and slide a cardbord tube over it. Hit it with a hair dryer on high for about 3 minutes and let air cool.

To wash cords:

For cleaning the cords  use the washing machine. If you are washing a lot use a pillow case and safety pin it shut. For single cords use a sock and pin it shut.

I haven't tried this, but I was told it works good.

Jim S.

[gands-antiques]

I tried the hair dryer and cardboard trick but it didn't get any better. Next, I got a piece of scrap coiled cord with rubber conductor insulators and I cranked up the oven to 250 degrees and balked it for 30 minutes. It didn't melt the scrap cord so I put my cloth covered coiled cord back on the dowel rod and baked it at 250 for 30 minutes and then i put it in the freezer over night.

I removed the cord from the freezer and let it return to room temp and then I removed the cord from the dowel and it is much better. The coil forms stayed together this time.  A higher bake temperature but shorter bake time are the only variables I changed so that must have been what made the difference. 

I think I am still going to get some of the spray stiffener to help permanently set the coils.

[unbeldi]

Good.  As the conditions of the cords vary, so do the results.

The freezer idea has always seemed totally against logic to me. Higher temperature makes sense, but lower does not.  One wants to achieve some softness, perhaps 'flow' of the material for reshaping, but freezing obstructs that.  Temperature and time do the work, both higher, not smaller.

That's why I suggested hot, not warm water, and with hot I have used water that I got to a boil first, if necessary.  That's close to 212 degrees.  When the jacket is wet, it doesn't work against the coiling as much, and dries into place.  It also prevents the temperature from exceeding the boiling point of water in case there are hot spots in the oven or the heat gun, as the temperature can only rise higher once all the water has evaporated off.

By the way, when making Vinyl spring cords for the 500 series, Western Electric heated them for eight minutes at 268 degrees.  That was followed by rewinding in opposite direction. But that is only for those thermoplastic jackets, not for cloth cords. I have not come across technical descriptions of making the cloth coils.

[gands-antiques]

Thanks, I know what you mean about the freezing part being an issue.  The only reason I starter adding that step is because a guy who worked in the WE cord shop told me he put his vinyl cords in the freezer after the bake cycle.

I had trouble soaking my cloth cord it hot water because I don't have a utility sink large enough for the length of cord and dowel. I just poured hot water over the cord for about 15 minutes.