Dear Dr. R.V. Shrink:
We just started a trip that will last two months. My husband is raising a stink and I keep complaining about it, which makes him even more cantankerous than he usually is. We have a 1989 travel trailer. It seems our exposed plumbing outlet for the black water tank is cracked right were it is connected to the tank. It is a slow, steady, smelly drip. Every time my husband tries some new super-duper glue or filler, he tells me it's fixed. Every time I tell him it's leaking again he gets mad and frustrated. I know it's a lousy job and hard to deal with on a trip, but I just can't stand smelling like an outhouse every place we park. Should I just put up with it or keep giving him the stink eye.
--Odiferous in Oregon
In your husband's defense, these are some of the hardest leaks to deal with and actually fix without having the tank replaced. There are many products that claim to be "stop leak" for ABS plastic, but they do not often work for any length of time. Not letting it drip onto the ground should be your first course of action.
Put some sewer deodorizer into a small bucket and contain it. If you can completely dump and dry the area around the suspected crack, I may have a solution for you, no pun intended. I have used this several times in the past and it seems to work better than anything else I have come up with. Get a small ABS fitting and grind or break it into very small pieces. I use a bench grinder that turns the ABS into thin, semi-melted, ribbon-like pieces.
Gather this material into a small can and add Acetone until it covers all the ABS pieces. Let this set for a couple hours, stirring occasionally. You will end up with ABS paste. By applying this paste to the dry, roughened area around the crack, the solution should meld into the fitting and crack. Let this dry and then add a couple more layers if needed. If nothing else it should last the rest of your trip. Often a new tank is the only remedy, which should be pretty straight forward if the tank is exposed. So work on this together and stop giving your husband the stink eye.
--Keep Smilin', Dr. R.V. Shrink