Now I'm no material scienmatist, but it seems to me that rubber dries out and cracks because it loses something over time. Is there any way to recondition a rubber piece that hasn't begun cracking, by reintroducing the thing that is lost?
Hmmmmmmmmmmmmmm....... 
A long time ago, someone recommended Gummi-Pflege at my local BMW dealer. Kinda like leather hide food for rubber. Usually takes a few applications, but seems to restore old rubber seals really well.
-Rob
I don't know how much truth there is to it, but I have always heard that brake fluid will make rubber soft again.
Gummi-pflege works well on window and door seals that have absolutely no load carrying capacity, but I don't think I'd try it on suspension bushings or engine mounts.
haha oh my. I dont think I want to recondition loaded rubber. I was thinking more like brake caliper slider pin boots, weatherstripping, etc etc.
Ive heard peanut butter works, never tried it though...
Never had any luck reconditioning old rubber.. just seems a stopgap measure.
Brake caliper boots are cheap, just replace them and the pins every second brake job or something. It'd be as much work to get in and treat them as it would to just replace them.
Gummi-pflege is good for door seals and the like though. I think Bill Dodge BMW probably has it, if not Bavauto definitely does. I have a bottle in the garage if you're ever in Saco/Biddeford.
Having worked in the elastomers industry for 12 years, I can tell you that nothing will recondition rubber chemically.
pinchvalve wrote:Having worked in the elastomers industry for 12 years, I can tell you that nothing will recondition rubber chemically.
Good enough for me.
Out of curiosity though, what is actually happening to the rubber when it ages? What causes aging, and what combats aging?
pinchvalve wrote:Having worked in the elastomers industry for 12 years, I can tell you that nothing will recondition rubber chemically.
Not with that attitude, if you can dream it you can do it!
pinchvalve wrote:Having worked in the elastomers industry for 12 years, I can tell you that nothing will recondition rubber chemically.
OK. Not disputing you. Simply asking for what you think happens.
Why is it that I can take an old garden hose that is stiff as a wooden plank, soak it in armorall and let it sit in the sun for a day, and it becomes soft? The same hose that has been sitting in the sun all summer, refusing to become soft. It certainly seems to be a chemical softening.
And secondarily, what have you seen with regards to preservatives that are supposed to prevent the degradation from happening in the first place?
