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OT? softening rubber

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  • OT? softening rubber

    I have a filler spout for a WWII Jerry can. It has the lever that squeezes a rubber sleeve to expand it to fit snug in the can opening.

    I did a google for what to use to soften the rubber since I can't seem to find a replacement. Kerosene seemed to be mentioned most often so I have had it soaking for about 5 days now and it has gone from hard as a rock to slightly flexable. At this rate it may take months to get it pliable and serviceable again. I probably can find some rubber to machine a new one and may have to.

    Does anyone have experience softening old hard rubber parts and what have you used? Did it work?
    It's only ink and paper

  • #2
    Most of the stuff (solvents) that will soften aged, hardened rubber usually also speed up the decomposition process.
    Your better off replacing the rubber.
    I cut it twice, and it's still too short!


    • #3
      Those spouts are for sale all over the place.


      • #4
        Yeah, but this spout is an an ti qu aka, antique, and I want to keep it. I guess I'll make a trip to the local rubber supply store in Louseyville Ky.

        I'll leave it soak until it's soft enough or melts, which ever comes first and yes, solvents speed up deterioration. It's just an experiment right now.

        Just wondering what others have done.
        It's only ink and paper


        • #5
          Originally posted by Carld
          I have a filler spout for a WWII Jerry can. It has the lever that squeezes a rubber sleeve to expand it to fit snug in the can opening.
          this sounds like the old style plugs for thermos jugs, and i had one for the drain for a small fishing boat. . . that might be a place to look. . .


          • #6
            Many years ago I read a book by James Melton, a famous opera singer and antique car collector, in which he describes his struggle to find the correct tires for some very rare car. He finally found them, hard as a rock, and the solution he or his consultants came up with was to weight them down and throw them in a lake for a few months. Apparently this softened them up, and they were good as new. Might be worth a try!


            • #7
              sometimes a brake overhaul kit is a packet of grease called rubber grease

              also the grease inside of a steering rack is of the sort that is kind to rubber .

              other than that i don't know

              other than silicone spray.

              all the best.markj


              • #8
                I have heard of running wiring harnesses through a dishwasher with the detergent to soften them. might want to wait till the better half is away for a bit


                • #9
                  Here are a few methods others have tried...


                  • #10
                    My friend who owns a rubber company has this advice:

                    "You need to know what sort of rubber you have.

                    See there are about 150 kinds of rubber... tens thousands of fillers modifiers and additives. Each combination requires a different cure agent.

                    Given that it's WW2 vintage... and that it's NOT latex... it's ether Ameripol or GRS. My money is on GRS. (Government Rubber: styrene)

                    Knowing this you can look up what solvents you need to rejuvenate said polymer."
                    Last edited by Grind Hard; 09-06-2011, 08:53 PM.
                    "The Administration does not support blowing up planets." --- Finally some SENSIBLE policy from the Gov!


                    • #11
                      Try doing a "Google" for rubber rejuvenator.

                      It's supposed to restore the "suppleness" & flexibility of the rubber.


                      • #12
                        I used to use a product called rubber renew for pinch rollers, etc. Electronics suppliers might still have it- I think it's one of the GC or MG chemicals products. It's a foul smelling liquid, but it works. Something to be done outside, if there's any size to the part.
                        Last edited by darryl; 09-06-2011, 09:28 PM.
                        I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-


                        • #13
                          If you want something suitable to make a replacement from, look in a good plumbing supply store for expandable rubber "test plugs". They are used to seal drain pipes for leak testing.
                          Don Young


                          • #14
                            silicone oil works great. Be careful with the sprays. Many of the sprays use a solvent to deliver the oil and that can harm the rubber.


                            • #15
                              I have used dot 3 brake fluid with some luck.Seems it has a ingredient to keep the rubber parts flexable.