Black tank done

Lid attached to tank flange with Gflex and then two layers of 9 OZ over the edges

           3/8 x 4 aluminium straps to hold it in

Mounting straps made of aluminium and twisted to conform to the tank bottom

Valve and sender mounted. Valve is Valterra pattern

Leak test, it took 309 lbs of water before it quit venting.

Oring slip fitting for shower and lav, 3" for toilet and depression for shower trap

1-1/2 bung for kitchen

Tank bungs and lid reinforcement

Used West System Gflex epoxy to install the tank bungs

Gflex is tough stuff and looks like it will be more than enough to hold bungs.
Here is a video of a Kayak sawed in half and stuck back together with Gflex

                             Ribs on inside of lid to stiffen it up.

  Added a couple vents to the marine plywood core so it can dry out if it ever gets wet.

                                Test fit of the top and bottom

Adapter fitting

 PVC adapter with oring seal like original. Need to lube this so it slides on easy. This is the bath drain connection and is really pretty much fixed in place. Hoping not to have to disturb it.

 Fitting bored and grooved for a o ring

 Original black ABS fitting had a straight pipe thread, not tapered. It was cracked.

Getting ready for West G Flex epoxy.

Tank top layup and fitting stick out

Heat shrink 2 mill poly for a smooth surface

                                                         laid up

toilet stick out

Bathroom stick out. This fitting is a weirdo, it has an o ring to seal to the pipe and what looks like a GM part number.

Original black tank removal, starting on the new tank top

Cut the top off the old tank to use for a pattern

Clearance for shower trap

drilled holes to mark features

using a stainless bowl to form shower trap clearance

heat melts foam

blocks set depth

used a wire wheel to clean the foam off the bowl bottom after it cooled

Tank clamps

                                         Packing tape for release

                Level setup

            Three layer of 9.5 OZ glass in this layup

                One side done

                    Clamps complete and cleaned up

Black tank level sender and drain

                         West epoxy with 405 adhesive filler

                                            Cup to keep flange centered

                           Two layers glass outside

                                  Test fit sender and valve