Mailport: November 2012
Antifreeze vs. Rubber
Does non-toxic antifreeze adversely affect rubber parts in marine plumbing? I just encountered an odd problem with the rubber parts in my three-year-old Jabsco head. The rubber of the flapper valve at the bottom of the pump and the joker valve both have enlarged. The flapper lengthened enough to hang up on the gasket portion, preventing it from sealing totally. The joker valve swelled to the point that it was a push to fit it in the discharge elbow. The only thing that I can think of that might have caused this is the non-toxic antifreeze that I use for winter storage.
Not all non-toxic antifreeze products are safe for use in plumbing systems. Those that are propylene glycol-based and are rated for plumbing should not damage the rubber; however, non-
toxic alcohol (ethanol)-based plumbing antifreeze can attack rubber. But the alcohol antifreeze typically dries out the rubber, not distorts it.
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