[VAC] Re: reinstalling holding tank

["Mr. Joy H. Hansen" <joytbrew@xxxxxxxxxxx>]

Hi,

My experience is with a '69 Safari holding tank.  I opted to remove the tank
as the floor was compromised across the rear.  Especially along the area
where the bumper hatch shelf directs water into the floor.  I've only seen a
few Airstreams with this area caulked to prevent damage.  Possibly your '67
already had the floor replaced?

With the toilet removed, the hold down flange is two parts.  A metal hold
down ring and a center funnel that along with the foam spacer seals the
toilet to the tank.  The center funnel is threaded and must turn counter
clockwise to remove.  Have your welder make a tool to just fit the
depressions in the funnel.  It will be tight!

The '69 might be the first year for the wide body and could mean that our
plumbing is different.  I couldn't get the Thetford gate valve to separate
and ended up cutting the valve body to get the tank out and check its
integrity.  Also, I had to cut the gray water line that drops through the
floor and connects down stream of the gate valve.  Planned for using a
rubber coupler to reconnect the gray water line.  The air vent is a slip fit
in the top of the tank.

Having done this restoration, there's one thing I didn't consider that I
note is part of my '74 Argosy.  The holding tank, besides allowing heat from
the furnace be forced around the holding tank to keep it from freezing, also
provides considerable support for the floor.  The dimensions of the tank
have to seal against the floor and I used foam fillers to accomplish this
with my Safari.  Now, I realize that the dimensions must be exact so the
housing is forced tightly against the floor.  My recommendation is to keep
the housing as thick as possible.  With regard to a drain hole, if water
gets inside the  housing, there's trouble in river city.  For small amounts,
the forces air from the furnace might clear the water.  BTW, I didn't
replace the gate valve and toilet hold down with Thetford as I feel that
they are vastly overpriced and are not readily available in case of future
problems.  There are several alternatives at RV outlets that are OK
replacements.  The repair kits for those I replaced on my Argosy were near
$35 and still lacked the pull rod that typically has the end rust off.

I hope you replaced the angle iron that holds the holding tank as it was
originally - welded tabs to the frame and the cross angle iron is bolted in
place?  An improvement I noticed on my Argosy is that two angle irons are
butt welded together to provide much improved support for the holding tank
housing.  Especially when the housing is intended to support the floor.

I used the angle irons bolted at one end as a slide to move the holding tank
(with tank) into position.  The housing was jacked into position and the
angle iron free end was then bolted.  The housing can't get out.  The toilet
hold down should be in position to replace the hold down ring/funnel.  An
important issue that  I've yet to solve is that the tank is not tightly held
in the holding tank (vertical).  I opted not to pull the tank to the floor
with the toilet hold down as the loaded weight might break out the toilet
fitting.

If you still have the old gate valve orientation and haven't cut any
plumbing loose, it should be very straight forward to connect the old gate
valve.  I opted to leave a large cut-out for the gate valve and make a two
section metal patch to seal the opening.  I had the tank out and opted to
carefully remove the Thetford gate valve and carefully press the new valve
in place.  An exact replacement wasn't available, so I had to seal one of
the typical two entry gray water fittings.  Also, I had to recover the ABS
fittings with careful grinding/filing as the replacement fittings are not of
the same dimensions.

I won't tell you that it's easier than it seems as it isn't.  There's an
obstacle to every solution I find that produces another obstacle!

Be sure your floor is sound before you button all this stuff up.  You won't
like the floor sag that might destroy all the work you've done with the
holding tank, etc.

                                             '69 Safari, Joy