Black Water Tank Solution

[Barry Gilley]

We are giving our 1985 center bathroom 34" Avion a second life as a permanent Rental unit. We have heard horror stories about the "mess" that can be made by attaching the black water drain to a permanent sewer connection without the benefit of a generous supply of both water and jostling motion within the black water tank to keep the solids suspended.

I have access to a septic system where the unit will be parked and I don't want to have to periodically dump the tank. My solution is to take out the old tank but can that be done from underneath or does the bathroom floor and all of the cabinetry need to come out?

[KYAvion]

When I opened up my bellypan to install heat pads for my black tank, it appeared as though it could be removed from below. On my 30R the tank goes across the width of the tank, and I imagine all the models are configured this way. Thus, it’d be extremely difficult to remove from the inside, so I can only assume the tank can be dropped from below.

[pbsled]

Just thought I would add from recent experience - If you pull the entire subfloor out anyway during a restoration of a 30P, it is possible and probably easier to pull the tank out from the top. I did have to break off the old 3" clamp because of rust, but I wanted to pull the tank up to try and preserve the level sensor wires that were impossible to unhook. The entire job was made easier by the removal of the rear door and I would opt for removing from the top if already into a floor project. However, be prepared to cut out the support braces if removing from below if the screws break off.

During the installation, I tried to minimize the use of some spray foam to hold the tank firm to make future removal from the bottom possible. I would assume one could piano wire through the foam at a later date. I would probably just cut the aluminum tank supports out next time and replace the braces rather than messing with the sheet metal screws.