I attempting to fix a black water tank problem for a 1978 17"
Boler Trailer. It appears that attempts have been made by previous owners to seal up around the drain pipe from tank to ABS 4" pipe that is connected to the release valves and mechanism. I cleaned off standard toilet wax and a little silcon as well as some black goopy stuff as well. The threaded 4" hole on tank appears to be the problem area. Looks like plastic around hole about an inch wider in diameter is cracked or leaking.
Since this is gross black water not sure if it is worth it to try with something like 3M marine sealer.
I was thinking of asking DM plastics if they had a waste tank for
Boler as well. We just picked up a potable water tank from them that is original
Boler mold. Worked great.
This blackwater is way more involved, will likely have to take down the one original wood panelling to access the vent stack if I replace tank.
Suggestions on trying this patch or opinions are most welcome.
Have fun out there.
Will