[Milsurplus] Softening hard coax

[Barry Hauser]

Hi Jim & crew ...

I don't recall that particular thread, however, I've had very good results 
rejuvenating mil power cables, test lead cables, etc. with CaiKleen -- a 
rubber cleaner made by the same outfit that makes DeOxit (Caig).  A pint can 
of it is fairly pricey.  I did find a similar item/smaller quantity, which 
is almost as good.  It might have been in Pep Boys.  Not sure.  Both have a 
very pungent citrusy/orange odor.

You wet a rag with the stuff and run the cable through it -- several 
repetitions, turning the rag to a clean spot.  It cleans off the old dead 
rubber and gunk.  I've used it on rubber test leads that were so bad I 
couldn't tell the red from the black -- also very stiff mostly from 
absorbing dirt.  Result -- bright and clean -- drape like new.  I've also 
used it on old zip cord, vinyl, etc.  You do not want to use a plain 
solvent, detergent or ionizing type cleaner (like 409, Simple Green, etc.) 
as these dry out the rubber and will kill whatever life is left in them. 
Also the ionizing type can leave salt compounds behind that can turn the 
insulation into a conductor.

The first time I used Caikleen on a power cable, lots of greenish, brownish 
stuff came off -- and after a while the rubber puckered.  I thought for sure 
I had ruined it, but about a half hour later, the rubber had shrunk back and 
was fine.  I suspect the solvent in it dissolves off the dead rubber and 
dirt and there's some oil or whatever that restores it.  I'm not sure if it 
would affect the dialectric properties of coax.  My guess is that most of 
the deterioration causing stiffness is mostly in the outer layer.  They can 
get crusty enough to cut through, even though the rubber underneath is 
recoverable.  So, be sure to avoid flexing them until cleaned off.

It's worth a shot.  While you can replace with new substitute, I've found 
that a lot of old mil cables were of a quality that's often hard to match. 
Some really old new old stock cables from WWII and just before (e.g. RAK/RAL 
power cables) are covered with some kind of preservative, or wax to start 
with -- underneath, the cables are like new.

Barry


----- Original Message ----- 
From: "James C Whartenby" <antqradio at juno.com>
To: <Milsurplus at mailman.qth.net>
Sent: Thursday, June 02, 2005 3:43 AM
Subject: [Milsurplus] Softening hard coax


>A while ago there was a thread discussing cures for hardened plastics.  I
> have a GR test set with coaxial cables that look like a petrified
> octopus!  So, what are the recommendations?
> Inquiring minds want to know!
> Jim
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