Argosy holding tanks

[SmokelessJoe]

Andy Thompson of Can Am explains the fact that current Airstreams have about 4 times the holding tank capacity of old Argosys this way:


“The reason tanks are larger now is that they are mounted close to the
axles which allows two things. The tanks can be much deeper because
ground clearance is not as big a concern by the axles. The other reason
is the weight does not matter next to the axles
either. As well the frame rails are 6" further apart which leaves more
room for the tanks.”

Has any one out there installed new, bigger tanks in an Argosy? Maybe moving the grey to the axles and using the space at the front for a bigger black?


Sergei

[overlander63]

Sergei, you can move the grey water tank to between the axles, and have more grey water capacity. The '70's Argosies had a 7-10 gallon grey water capacity, so anything more you can put in would be good.
The black tank, however, usually rests on the floor in the bathroom, under the toilet. You really can't do much moving around there without major surgery. Black tank capacity uis about 10 gallons.

[CanoeStream]

Black tank capacity isn't as readily exceeded as grey (though the above floor black tank capacity isn't great to begin with). One might want a direct sewer connection if they like to do extended stays. Airstreams in general and the lighter older trailers in particular have the ability to scoot -- and who doesn't empty their tanks first?

My Argosy manual seems to speak for all lengths in '76:
Black tank (rear bath): 12 gal
Black tank (center bath): 23 gal
Grey tank (rear bath): 10 gal
Grey tank (center bath): 16 gal
Water tank: 30 gal
[Center bath is an option only on 28' Argosy. I don't know if that high capacity is all above floor. The water tank is above floor under the front window in my 24' -- can't speak for all.]

My 2006 25' FB has a 39 gallon water tank just behind the axles, a 39 gallon grey tank just forward of the axles, and an 18 gallon black tank just forward of that. Here's the catch -- all three tanks protrude about 6" under the belly wrap. All three tanks on my trailer look exactly the same -- about a 5.5' wide, 22" fore-and-aft black plastic box protruding 6" below the belly wrap. There are 4 heavy galvanized straps holding each in place. Not wanting to take my new trailer apart quite yet I cannot describe the insulation and heat ducting.

Silvertwinkie first mentioned the projection of the tanks 6" below the belly wrap. I've got to take it on faith that Airstream has the heat ducting done correctly. The noteworthy point is that the described 6" below the belly wrap places all tanks approximately 2" below the axles -- the outside axles near the hubs! These definitely aren't trailers you want to be hauling in to the deer shack.

[SmokelessJoe]

Thanks for the information Canoestream and Overlander.

I'm enroute now and don't have access to a SE 25 floorplan. Does the toilet exit directly into the tank on the SE?

Must a marine/trailer toilet always dump into the tank or can a clever run of large drainage pipe be employed for a short distance.

I would like to get rid of the above floor black tank.

Sergei

[overlander63]

Originally Posted by SmokelessJoe

Must a marine/trailer toilet always dump into the tank or can a clever run of large drainage pipe be employed for a short distance.

I would like to get rid of the above floor black tank.

Sergei

Sergei, if you are clever with the use of PVC, you can rig a pipe to go from your toilet, into the floor, and forward to a location between the axles for your black water tank. If you are really good, you can then hook the lines back into the original outlet for the black and grey tanks. This would do a couple of things for you.
1- It would open up more storage space in your bathroom, although I don't know what you would put in that space.
2-It would slightly lower your center of gravity, and could increase your black water capacity. You theoretically could carry more black water without straining your frame.
3- It would give back up to 80+ pounds to the front of the coach for increased tongue weight, for added stability. Ten gallons of water (plus the contents of that waste water normally in the tank) at 8 pounds per gallon is a lot of weight to take off the rear.

[SmokelessJoe]

Originally Posted by overlander63

you can then hook the lines back into the original outlet for the black and grey tanks.

Terry:

I can't follow the above. Can you clarify?

I plan to take the belly pan off to see what's where, so to speak.

My thought was to remove the above-the-floor black tank and locate a new, larger one someplace nearer the axles. But how to ensure the gravity flow of the black stuff to the tank?

( I imagined a new exit dump drain for the black tank being somewhere near the wheel well)

Perhaps it will prove simpler to install a NEW grey tank mid trailer and redirect the toilet to the existing grey tank. ( Making the current grey the new black).

The existing grey appears to be below the floor at the front, near the black tank.

I think re-plumbing the waste water flow could be done fairly easily.

I want to redo the rear bath in my 76 Argosy, getting rid of the ABS sink/counter in the process. What I want most to get rid of is that toilet sitting up on a ledge.

A floor mounted toilet will provide more space but most of all it will look neater, cleaner and give more design possibilities.

Any thoughts gratefully received.

I have found an RV supply company in California on the net that will make plastic tanks to order in any dimension. There may be more suppliers like that out there.

Sergei

[overlander63]

Sergei, your coach should have a common outlet for the black and grey tanks. By me telling you that you may be able to plumb the new tank so you can still use the original valves and outlets was so you didn't have multiple dump locations on your coach. As far as making the waste water drain, just remember the first rule of plumbing: S#*t flows downhill. You won't have to make much of a downslope to make an effective drain, although the steeper the better. If you take out you black tank, you will notice it has a definite slope to the corner with the drain hole in it.
After thinking about this overnight, I have realized a small problem, but not insurmountable: You should look into a tank monitoring system, as you will no longer ne able to physically see how much black water you have in your tank until it is full to the top.

[SmokelessJoe]

Terry, yes, I'd overlooked the common outlet in my planning.

One would want to maintain that, 'though if the tanks were relocated, the common drain outlet might also be moved somewhere closer to the new locations.

If I have the pan removed it will allow the frame to be inspected and provide an opportunity to see the current sewage system, then reimagine it.

Thanks.

Sergei

[SmokelessJoe]

Friends:

I posted an update with photos recently. Check the project out at

http://www.airforums.com/forum...ase-18448.html

if you are interested.

You’ll see that the trailer has been carefully de-commissioned inside and out and the pan removed.

The frame was in good condition. Despite 30 years having passed, some of the 1” x 2” steel tubing running lengthways atop the frame was in the original blue-black factory condition.

Nevertheless, Phil sanded and sand blasted the rust that develops around plumbing and where seams in the body panels and belly let in moisture over time.

You can see that the frame, hubs and axles have been primed and painted and we are now ready to move ahead with the remodel.

The first order of business is to decide how to re-plumb the trailer with new holding tanks.

The 1976 Argosy 24D had a 10 gallon black above the floor and a 12 gallon grey below it, both at the rear.

A 10 gal. black is OK. What I don’t want is the tank above the floor, taking up space inside the bathroom.

A 12 gal. grey is unacceptable.

This is our chance to bring the tanks to contemporary Airstream standards or better.

There are four well-situated locations between frame rails and crosspieces were we could install new tanks.

At the rear, 32 x 48 x 8 inches.

Just before the axles 34 x 56 x 9 inches.

Between the axles 30 x 56 x 9 inches

Just after the axles 22 x 56 x 9 inches

These spaces are clear, without having to modify cross struts. The dimensions are outside, allowing for 1” foam insulation all around.

Through Wiltsie, I have access to the Coast Distributors catalog. They carry about 20 different sizes of polyethylene tanks with floors sloping toward 3” outlets.

A tank in a size that would fit the between the axles would give a 43 gallon capacity for instance.

The task will be to find tanks with the outlet in a location that will make convenient plumbing and dumping possible. In the unlikely case that we can’t find one among their stock, we will have to custom order.

Our choices seem to be these:

(a) Install a new black tank, below the floor at the rear, with as much capacity as will fit the space

Install a new grey water tank near the axles, re-plumbing the shower drain and both sinks to this location.

Or, maybe better,

(b) Install a new European style cassette toilet. No black tank is needed; you remove the “cassette” through an access hatch created in the Argosy body.

Keep the present 12-gallon grey at the rear. The shower and bath sink already drain to it. Nothing to change.

Install a SECOND grey, 40 gallons or more near the axles, exclusively for the kitchen sink.

We will try to drain both greys to the present dump valve. If not easily possible, we can have a separate dump at each of the two tanks.

Do you have any suggestions or comments to offer?

I would especially be interested to know if anyone has used, bought or seen a “cassette” toilet.

Sergei

[wahoonc]

Originally Posted by SmokelessJoe

I would especially be interested to know if anyone has used, bought or seen a “cassette” toilet.

Sergei

Sergei,
I have one in my Coleman popup, it does the job fine, it is good for about a week at a time with two people using it. One advantage IMHO is that it has its own water supply. It holds maybe 3+ gallons in the waste tank.

Aaron

[SmokelessJoe]

Aaron:

Is this the type you have?

http://www.thetford.com/permanent_cassette.cfm

Sergei

[wahoonc]

Sergei,
Yep the C4 is the one that is installed in the big Coleman popups...holding tank is bigger than I realized

Aaron

[overlander63]

Sergei, you have made a great start. Your statement about the black tank gave me an idea. Since you are doing some modifications to the waste plumbing, why not move the grey tank forward, as you indicated, and simply cut a hole in the floor under the black tank? You can theoretically double the black water capacity by extending the tank under the floor, and your weight will be almost the same at the rear of the coach, since you will be moving the greey water forward.

[SmokelessJoe]

Terry,

Yes, that’s what I called option (a).

I’m interested to explore (b) more fully because:

- It would mean buying and installing one tank instead of two.

- I’m not sure we can slope the drains for the shower and sink back toward an axle area grey tank efficiently. I suppose we could use some sort of shower drain pump to help do the job.

- We’d have to plumb the grey water back again, to a common dump valve, so that it could flush out the drain and sewer hose, after dumping the black.

The idea of a cassette toilet has some appeal. They seem common sense and our job might be easier for us.

I know these toilets are widely used in Europe, the standard I believe, but I haven’t seen one.

Do you know anyone here who knows about them?

Sergei