Once again I'll be the guine pig. I have a 40 gallon Vetus
holding tank. I would rather have a rigid tank but I had to remove that (15 gal) because the PO installed it over top of the
bilge pump. Of course the
surveyor didn't notice that, or many other issues.
Anyway, after several years of good
service something happened ( that's code for I screwed up) and allowed the tank to be over filled, twice! That stressed the top fitting. Is not leaking (it did, eeeeewe!) but it ain't good, so I gooped it up with 5200.
Now it's a matter of time to see if it will fail or hold up. I only did this last week. And we are hauling shortly for 6 months so it will be a while.
I MAY break down and buy a new one, just to be safe.
My second thought concerns venting, Peggy you still here? We have a
Lavac toilet. Smell has been an issue. I'm starting to using some KO which seems to be helping. My thought is to leave the lid up and
pump the bowl dry periodically, like twice a day. The thought is to inject some air into the tank to feed the KO. Any thoughts?
My third thought would be to use some aircraft two part
fuel tank sealant on the joints. If anything is stickier and stronger (and messier) than 5200 it is that. You can buy it at aircraft online stores (FlameMaster or 3M) or pay a bit more and buy the same stuff from Boatlife. In fact that's what I'll likely do, seal the fittings with that goop in the fall. It's wicked tough.