Need advice on unusual black tank situation

[scombs]

Maybe get a “heat gun” at Harbor freight and heat up the bottom of that tank and reshape it into a poop ramp into the lower level?

[mgoldstone]

Originally Posted by 153stars

If you move tank and there is almost no clearance for cap on pipe.You should be able to find a pvc plugs to fit in a sch40 pipes ,then use in a short pipe as plug in grommet hole a tab of metal or plate and screw to keep from pushing in tank . You could cut a cap down shorter for lesser clearance. There's no pressure and will be on top of tank . Hopefully bottom drain can just be repiped.

To make a watertight connection to a HDPE tank I have used Uniseal bulkhead fittings, Mr Sticky's 2 part epoxy and a propane torch to flash the HDPE tank before drilling the hole for the Uniseal. The heat flash changes the surface structure of the HDPE tank facilitating a superior bond with the epoxy. The epoxy is optional but in my opinion desirable when dealing with contaminated gray and black tank water and vibrations while traveling in your RV.