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 Post subject: How to soften rubber insulation
PostPosted: Mar Mon 05, 2018 7:17 am 
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Location: Vancouver Island, Canada
To soften hard rubber insulation on a 1950 speaker cord, I have found the following suggestions:

1) Heat with a blow dryer or in the oven (when alone in the house, no doubt). Sounds temporary.

2) Soak in oil of wintergreen and alcohol.

3) Spray with silicone spray and seal in a plastic bag for a day.

Has anyone tried any of these or found something better?

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Mon 05, 2018 7:50 am 
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I have used ArmorAll (Original Protectant) on rubber insulated test leads to clean them and slightly soften the rubber so it would not crack.
For initial cleaning, I used paper towel saturated with the ArmorAll to wipe the wires. Then I lay the wires flat in a pan between layers of paper towel, also saturated with ArmorAll. The time for soaking is indefinite, monitor and stop if/when you can feel some softening. HTH

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Mon 05, 2018 3:08 pm 
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Acetone is the best..Some use brake fluid.


Last edited by hoffies2 on Mar Mon 05, 2018 5:28 pm, edited 1 time in total.

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Mon 05, 2018 4:41 pm 
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I use a heat gun...

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Mon 05, 2018 5:51 pm 
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I successfully softened the rubber cup of my Crosman pellet gun by soaking it in a solution of 1 part Oil of Wintergreen (bought at aroma therapy bar) and 4 parts Xylene. Oil of Wintergreen is methyl salicylate, an agent that keeps rubber pliable. The Xylene opens the pores of the rubber so the Oil gets in. Over time the Xylene evaporates. It causes the rubber to swell, so monitor it in 30 minute increments. Another piece of rubber swelled so much it split apart. The rubber shrinks to original size after the Xylene has evaprated.


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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Mon 05, 2018 6:52 pm 
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What happens when solvent treated cord (dry) is near or lays upon a fine wood finish, floor tiles, painted finish? Oops?

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Mon 05, 2018 7:23 pm 
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Macrohenry wrote:
I successfully softened the rubber cup of my Crosman pellet gun by soaking it in a solution of 1 part Oil of Wintergreen (bought at aroma therapy bar) and 4 parts Xylene. Oil of Wintergreen is methyl salicylate, an agent that keeps rubber pliable. The Xylene opens the pores of the rubber so the Oil gets in. Over time the Xylene evaporates. It causes the rubber to swell, so monitor it in 30 minute increments. Another piece of rubber swelled so much it split apart. The rubber shrinks to original size after the Xylene has evaprated.


I love Xylene, and Xylol, great chemicals, a bit tricky with plastics, as in don't do it!

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Mon 05, 2018 10:03 pm 
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Location: Mpls, Minnesota
hoffies2 wrote:
Acetone is the best..Some use brake fluid.

I have some rubber suction cups from a transoceanic that I soaked for a couple of years in brake fluid, didn't soften them a bit.

I have yet to find anything to soften rubber

Dave


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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Mon 05, 2018 11:10 pm 
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I once put the spray tube for wd-40 on the can with a rubber band. They never seemed to work very long as they would get stiff as dry pasta and crackle off. So much for silicone preserving rubber. I use this stuff to preserve rubber. It's the same stuff the companies would include with RF connectors that had rubber O rings. I use it on seals and car door weatherstripping and other rubber items.

https://www.harborfreight.com/85-gram-s ... 93744.html

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Tue 06, 2018 1:16 am 
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Thanks, I looked up the SDS for Super Lube but didn't get much from that, such as the active ingredients. It's a well kept secret, or it's just grease.

Oil of Wintergreen seems to be magical stuff. I am thinking acetone would work similar to Xylene.

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Tue 06, 2018 1:36 am 
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It's a synthetic lubricant, similar to synthetic oils. It is supposed to be safe for use with food processing equipment.

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Tue 06, 2018 3:12 am 
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Location: Simonton, Texas
I have used glycerin which I have harvested from bad pressure gauges to soften rubber.

My Jeep wiper blades lasted 5 years.

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Wed 07, 2018 4:11 pm 
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I have some NOS resistor line cords in the orig. boxes. If you try to uncoil them you can hear the rubber insulation cracking on the wires. Next step, soak coil in acetone for an hour, rubber softens and cord can be uncoiled into a straight line. Within a short period of time the rubber goes back to original brittle state. The cord is useable in the straightened out position, never to be coiled up again.


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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Wed 07, 2018 4:27 pm 
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This guy sells Isopropyl Alcohol and Glycerin as a rubber rejuvenator:

https://www.ebay.com/itm/12oz-RUBBER-SO ... 2905740322

We used Rawn Rubber Re-Grip back in the day. Rawn Chemicals made all of the house brand stuff for our local distributor - freeze mist, spray cleaner, tuner lube. They also packaged the lubes for PTS/Precision Tuner Service.

Re-Grip looks to be still available:

https://www.amazon.com/RAWN-RUBBER-DRIV ... -CAPACITY/ <- No affiliation, I've never bought from....

Made for phono idler use, it'll quickly swell up most rubber components, and we used to soak the BSR and Gerrard motor bushings in it to soften them up.

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Thu 08, 2018 4:24 pm 
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Thanks, guys. I think I still have some acetone if it hasn't evaporated out of the bottle. It is encouraging to know it softens the rubber temporarily, so must be similar to Xylene in that respect. Then either glycerine or wintergreen to prolong the rejuvenation. I'll give one of those a whirl on some dry cords and report back eventually.

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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Sun 11, 2018 3:18 pm 
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[quote="westcoastjohn"]........

Oil of Wintergreen seems to be magical stuff....... quote]

Yes,it certainly seems to be.According to this ad on Amazon,it's poisonous,yet surprisingly tasty. :?

Important information:

Safety Warning
Keep out of reach of children. Not for internal or topical use. For aroma-therapeutic use only. May be harmful if swallowed. Consult poison control center or an emergency room immediately accidentally consumed. Natural essential oils are highly concentrated and should be used with care.

Ingredients
Pure wintergreen oil

Directions
Wintergreen Oil (Gaultheria procumbens) is great tasting and useful internally or externally. This oil is the natural smell and taste used in many gums and food products.


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 Post subject: Re: How to soften rubber insulation
PostPosted: Mar Tue 13, 2018 4:24 am 
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Mike C. wrote:
westcoastjohn wrote:
........

Oil of Wintergreen seems to be magical stuff....... quote]

Yes,it certainly seems to be.According to this ad on Amazon,it's poisonous,yet surprisingly tasty. :?

Important information:

Safety Warning
Keep out of reach of children. Not for internal or topical use. For aroma-therapeutic use only. May be harmful if swallowed. Consult poison control center or an emergency room immediately accidentally consumed. Natural essential oils are highly concentrated and should be used with care.

Ingredients
Pure wintergreen oil

Directions
Wintergreen Oil (Gaultheria procumbens) is great tasting and useful internally or externally. This oil is the natural smell and taste used in many gums and food products.
Right, I thought about that, "will it be safe for the grandkids?" Well, hopefully, the Darwin Theory of evolution has already eliminated any kids that chew on wiring. Just kidding. But actually these kids are pretty smart. My grandson hasn't turned 3 yet, sent grandma a picture he took himself with Dad's cell phone. He just searches for her icon to find her number and clicks Send. :o

But if wintergreen makes wiring smell and taste like gum, maybe I should use glycerine.

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