On my black tank I had an issue where in assembly someone placed a 1x4 board across the very edge of the black tank and then screwed it into the frame. Well the tank is slightly deeper than the frame it was mounted, so the board, when tank was weighted with sewage, would hold its position but the tank swelling put pressure on a corner of the tank and split it with a gap of about 1/4 inch. I took down the underbelly and removed the tank, and yes it was a pain, a real pain. I actually repaired the tank rather than buying a new one. I first was able to fill the gap internally by using a small amount of black roof material that comes in caulking tubes and pieces of ABS which sealed the tank, then By chipping up ABS fittings, using that to mix with the so called ABS glue and using plastic screen wire, spreading over a rather large area, and several layers and several days to cure, and then covering with liquid rubber. I then reinstalled the tank, without the suspect board. I mirrored hanging the tank just like the gray tank, which is the same size and config but did not have the 1x4 board. I have filled it to the top with water, bounced 100 miles, just to test it and all still good. We have used it several times since, in the heat and cold and all is good so far. I do expect that I will probably need to buy a new tank in the future, but for all intent and purposes, the repair is about 5 times thicker and stronger than the original tank. It behooves me that the weight of these tanks are solely held up by the lip or edge of the tank and that quality control, if there is any, did not catch the board and its placement.
2015 Sabre Silhouette 312RKDS
2011 Ford F-250 Stock