Maintaining O rings

[admiralslater]

Recently got a leak in new rudder bushings which use O rings on the top . The bearings had been on the boat uninstalled for several years before use . Turns out the O rings harden in the high heat of the tropics . I have purchased new ones . I want to keep them pliable with Vaseline or some thing . Any ideas

[model 10]

You need to up-grade to a better O ring. The newer fluorine rubber O rings are it.

[transmitterdan]

Superlube?

[a64pilot]

Regular ole O rings have a life of five years if kept in their sealed packages.
So sayeth the Military and I think the FAA although I can’t quote chapter and verse.
In particular it’s ozone that will rot them the quickest.
Depending on type of material Vaseline or any other petroleum product could be very bad.

Shelf life by material
https://www.oringsusa.com/html/shelf_life.html

[a64pilot]

I have had very, very good luck with Viton O rings in scuba applications. All I have are brown in color, had to miss that.

[Sailmonkey]

Neoprene orings have a shortish life exposes to the air. The answer is a different compound. Something like nitrile or Alfas will last longer, especially when stored in a light blocking sealed plastic bag

[GordMay]

Recommended O-Ring Shelf life
5 years: Polyurethane (millable), SBR, Natural Rubber, Polybutadine, Polyisoprene
15 years: Nitrile, Neoprene, HNBR, Polyacrylate, Butyl
Unlimited: Ethylene Propylene, Fluorocarbon, Perfluorinated Elastomer, Silicone, Tetrafluoroethylene Propylene (Aflas®), Fluorosilicone.

ARP 5316 ☞ https://www.oringsusa.com/html/shelf_life.html