[VAC] Spare tire + grey water tank

["Robert / Susan Harper" <rharper@xxxxxxxxxx>]

Let me just head off any suggestions that may arise from that subject line:
I DON'T think it is feasible to use the spare tire as a gray water holding
tank, although it's an interesting idea.

A little thinking out loud here.  All potential gray water tank locations
behind the axle will require either removing or re-locating floor/frame
braces (or fabricating around them), or using smaller multiple tanks.  Since
my fresh water tank is at the front of the trailer, it would seem like a
good idea to put the Grey water tank at the front, also. Then the weight of
the water stays in about the same location whether fresh or Grey, and I
don't have substantial changes of balance. There's a large space under the
floor in the front (under where my dinette will be) which is unobstructed by
floor or frame bracing.  I think this is the area that has been discussed as
a spare tire storage site. Today I will try to calculate how many gallons
could be stored in that area under the front floor.

Has anyone ever fabricated a holding tank from stainless sheet metal? I know
a guy in the business who could do the work, and I'm thinking it could be
designed to have some integral s.s. bracing welded in at the time of
fabrication.  Welded/bolted/strapped in place, it would probably even
stiffen the floor a bit. Mount it tight to the underside of the floor (seal
bottom of floor first to guard against condensation)and put the rigid foam
insul. below the tank.  Could be made from ABS or polyethylene, too.  I'll
compare costs.  The worst problem I foresee is routing the draining gray
water to the tank. Might require an above floor pipe hugging the wall coming
to front (from galley) streetside.

Which raises another problem. I assume these tanks require a vent stack to
let air out as water goes in, yes? So here I am, back to snaking something
bigger than wires up the inside of the wall .....  Would a piece of flexible
clear vinyl tubing suffice as a vent pipe to the roof? How big?

Re: tire carrier.  I'm leaning towards the rear bumper mount. My rear bumper
has had a steel pipe welded onto the back of it about 5" in diam. (nests
right into the concave shape of the bumper).  I've cleaned it up to look
pretty decent, and it does make the bumper much more substantial.  It had a
crudely fashioned tire carrier welded to it when I bought it (1/2 x 3 x 3
angle), but I removed it (was crooked, off-center, bad angle).  Maybe it
wasn't such a bad idea.  (Former owners stored their sewer hose inside the
pipe. Maybe I'll use it for awning poles or short fishing poles.)  I saw
pictures of Roy Lashaway's bumper-mount spare, and with the Continental
cover (s.s. ring), it looks pretty good.  Maybe I can finagle a thin sheet
of polished alum or stainless for the center of it, too.  Is the center
usually plastic or what?

The pro's of the rear carrier would seem to be:
    - clean and easy access to spare if needed
    - provides substantial counterbalance weight for batteries (if I end up
squeezing them
    onto the tongue behind the propane tanks - still a possibility)
    - leaves space under dinette for holding tank possibility
    (I don't have one of those storage compartments between trailer and
bumper, and there is no access panel under rear window)

Cons:
    only one I can come up with is the aesthetics, which seems surmountable,
or at least acceptable

Suggestion/yeasayers/naysayers please.

BH62GT/SC

p.s. Fridge arrives today!  I went with the larger Dometic 2410 - plastic
stuff looks easier to disguise on this one, and it has 3.7 cubic feet. Susan
may have to stand on her tiptoes to use the high galley counter, but hey,
life is about compromise...