o-ring lube and installation?

[Jennifer]

I'm replacing the 2 inch o-rings and split nut union on my Balboa heater. The O-ring is rubber and the split nut union holds together a metal pipe (on the Balboa unit) and a PVC pipe.


What kind of lubricant is safe to use on the rubber o-ring, metal, and PVC? I know Vaseline deteriorates rubber. Would a silocone lube be ok, or can I used cooking oil/Crisco, OR do I need to go buy some Plumbers Grease? I have heard that the o-ring lube is a rip off and I don't need it. I've read all different answers to similar questions on the plumbing forums.


I don't want to use anything that will deteriorate the rubber o-ring faster than they normally deteriorate on their own. They are a pain to replace, not because putting in an o-ring is difficult, but because these particular o-rings that I have must be ordered on-line and take several days to be shipped (only one site sells them, too.)


One other question: if water is trickling out of the Balboa metal housing, can I put the o-ring on, or should I want until both ends are dry, lube them up and then attach them? My boyfriend and I disagree on the answer to this, so...can't wait to hear what you have to say!


Thanks in advance for all responses!

[Mary]

They don't need to be dry to replace. I would recommend using a silicone lubricant. I wouldn't recommend any of the other products that you listed.