Softening Rubber

[BaronYoungman]

Any ideas on how to soften up some semi dried out rubber?
Bob

[graphic66]

Maybe some brake fluid, it works great as tire dressing, just don't get it on any paint. It has lots of rubber conditioners in it.

[awolff280sl]

90% Silicone grease (not the spray) has worked for me.

[wwheeler]

Might try 303 protectrant. It will definitely protect what is left.

Use caution with brake fluid. The reason rubber elastomers swell in brake fluid is because the rubber is incompatible with the fluid. The swelling is a reaction to this incompatibility. If you were to weigh the part before and after exposing it to brake fluid, you would see that the part has absorbed the fluid. If you try this with an elastomer that is designed to be in brake fluid, it should neither swell nor shrink. I would not do this to parts that hold pressure or are under stress or strain.

[Jonny B]

Plain old glycerin work pretty well too.

[Bullethead]

Plain old glycerin work pretty well too.

+1 to Jonny B. The least damaging thing for old rubber, simply wash the part thoroughly & dry, rub glycerine into the item and bag it until re-using.
It will restore elasticity and shine. I've got treated 1978 vintage Michelin XWXs bagged this way for over a decade. They look like new tires. Just for show, obviously. Brake fluid will just dissolve the surface and will ultimately damage the piece. Never use it as a tire dressing, it weakens butyl & natural rubber!

[Witt]

......just applied "petrol-jelly" to the new whether stripping to keep it from wearing to quick, maybe that will work ?!

I also gave the same treatment to my  daily driver a 86 VW Jetta to keep the whether stripping from freezing !

CHEERS !
WITT !

[RickM]

......just applied "petrol-jelly" to the new whether stripping to keep it from wearing to quick, maybe that will work ?!

Petroleum Jelly (aka: Vaseline) attacks rubber. Isn't it a no-no to use it together with condoms? 

[wwheeler]

Rubber that is specified for contact with oil is OK with petrol-jelly. Rubber that is used for weatherstriping and such should not be in contact with petrol-jelly. The degradation may not be immediate, but it will break it down eventually.

It may all look black, but NOT all rubber is the same. Be carefull where you use it.