Finally got the new Black Tank and Grey Tank for our Avion C-10!
These have been a long time coming, I started designing them over a year ago and explored a lot of options on paper and with 3D mock-ups built from foamcore board. I ended up having my drawings quoted at several custom fabricators, the quotes I got back varied greatly. I ended up having them built at Triple M Plastics in Maine, they not only had one the best quotes but also gave me the most confidence that they would be built the way I wanted. The build quality of the tanks I received was amazing and they were spot on to my drawings. The Black Tank is similar to the original, but about 2” taller which is good because it’s pretty small being at about 7 gallons. I didn’t realize it until it was too late, but I think if you were to use a "short" Dometic toilet the black tank could be another 4” taller which would increase the capacity by another 3 or 4 gallons, if had already bought a “tall” toilet but maybe an opportunity here for someone reading this.
Our Avion did not originally have a Grey Tank, the sink drain lines were connected to the main dump valve below the gate so grey water would just run onto the ground, into a bucket, or to campsites waste connection if you were attached at a site with a full-hook ups. I designed a Grey Tank that hangs from the floor inside the grey fiberglass fairing under the bathroom. This tank is small even by truck camper standards also at about 7 gallons, but it allows us to use the sinks when traveling and easily dump the grey water separately from the black tank. The tricky part of a grey tank in this location is that it needs to be below the trap for the shower drain. I used a HepvO trap to save height over a conventional trap, and because it uses a rubber valve it also keeps odors from coming up through the shower drain. I cut-out the bottom two layers of flooring in the area just above the trap to gain an additional inch of height in the capacity of the grey tank. We are rebuilding bathroom to allow it to still function as wet bath which will be a nice feature to have when boondocking, but if you want a larger grey tank eliminating the wet bath might be something to consider.
