Gray water tank - 1971

[gamakai]

How hard is it to add a gray water tank? I am inquiring about adding a tank to an AS that needs no other work or restoration.

[Belegedhel]

I am in the process of doing that very thing. I am doing a shell-off rennovation, so adding the grey tanks is a fairly minor part of the fun. It is hard to tell you the level of difficulty without knowing the range of trailer years you are looking at, but it isn't rocket science, many of the vintage trailer owners have made this modification. It isn't a "cut and paste" sort of operation either--you will be performing a customization that is going to take some thought and planning. There is no "out of the box" solution.

The biggest question that plagued me was whether to use a single large tank that would hang below the belly, or to use two very shallow tanks that would stay within the frame rails. Once that decision was made, and the tanks acquired, I have actually been able to make some steady progress.

good luck.

[purman]

I am in the process of putting 3 in. 2 grey tanks and 1 fresh tank on top of the other fresh tank. Mine hand bellow the belly pan as I wanted 60+ gallons of capability. The key is finding a why to get your plumbing to them, not the tanks. you can get tanks here.
Page 3 - RV Water Tanks

[Minno]

We also added gray tanks - two of them. One is 4 inches deep and sits above the rear axle. The other one is 5 inches deep and sit behind the rear axle, and it hangs below the original belly pan about 1 ½ inches total including the frame and plywood support. I customized the belly pan to enclose this tank when we installed the new belly pan this year. I also built the tanks myself to maximize the space in between the main frames and cross members rather than pay for custom sized tanks.

You can get details in our thread: http://www.airforums.com/forums/f185/little-girl-refurb-50967-19.html starting at post 259.

Chris

[Belegedhel]

Chris,

What technique did you use to construct your own custom tanks (fiberglass, plastic weld, etc)?

[gamakai]

I should have stated that I am looking at a 1971 Globetrotter that needs very little work but needs a gray water tank.
Mike

[Bauxter]

I would use the gray tank that Vintage Trailer supply has available. It fits within the belly pan limits, which means minimal, if any belly pan alteration.
You would still need to alter the incoming drain lines and vent up in the cabin, as well as either tie into the outgoing waste drain line, or create a second one.
I think whatever tank you choose, there will be at least some slight frame additions/adjustments to support the tank.
On the flip side, you could get a much bigger tank, if you can extend below the belly pan....a little more work.
Vintage AS tank link below
Gray Water Tank

[Belegedhel]

Ok, here is a picture of my upside down frame sans-axle with two vts tanks installed. If I had had to do everything I've done in the last few weeks from the underside of the trailer, I would have thrown in the towel.

[Bauxter]

Wow, Bottom-side up would make it easier. Do you have a rotisserie to spin it around? I dropped ABS tanks from the top-side, but if you put them in from the bottom, I am guessing it would have been as difficult as the VTS tanks. I don't think there is a magic bullet for this task.

[Chuck]

from what I can see in the pic, it looks like when you flip that thing back over, the tanks are gonna just fall out. How do you propose to prevent that?

[Belegedhel]

You can't see the wads of bubblegum under the tanks! Seriously, I made panels that will slide into angle supports much like the panel that supports the fresh water tank. I'll slide them into place before I flip.

[Belegedhel]

My comments earlier about all that I had done recently and throwing in the towel was more directed at the fact that I replaced the entire belly pan. The tanks were the easy part.

[Aerowood]

Originally Posted by Belegedhel

Ok, here is a picture of my upside down frame sans-axle with two vts tanks installed. If I had had to do everything I've done in the last few weeks from the underside of the trailer, I would have thrown in the towel.

Nice job.

[Belegedhel]

Aero wood--thanks!

Bauxter--no rotisserie, I used the two gantry frames I built and used to lift the shell and three chain hoists to flip the frame. Worked pretty slick.

[Bauxter]

Team, I think we may be in the process of hijacking Gamakai's thread, not sure, as I have misplaced my official Forum user handbook.
Gamakai, I hope we haven't sidetracked you.

[Belegedhel]

My apologies if we have veered off track. To get back on topic, I would reiterate that adding a grey tank to a 70's era GT isn't terribly difficult, and that if one chooses the VTS tanks, they fit nicely inside the frame as pictured above.

Some modifications are required, namely, one must devise a means of support for the tanks, whether it is straps or slide in panels like I am using. I also made slight mods to two cross members so that drains could pass from tank to tank as low as possible. The center belly pan is one continuous sheet from the rear bumper to just behind the fresh tank. One option may be to remove it and then put it back all in one piece, another would be to create several sections of belly skin, as I did.

When I started working under my trailer, I stacked some 2 x 12s under the wheels to raise the trailer 3 inches to give me some more working room. I also got an angle drill, which was helpful for drilling out the rivets in the belly pan. Get ready for all kinds of nasty to fall in your face as you work.

Good luck.

[Belegedhel]

Another thought on the level of difficulty of adding a grey tank: no matter what tank you choose, at some point you will have to order the tanks and possibly specify locations for drains/ fittings. Some tanks are constructed such that you can drill your own hole where you need it and put in a rubber fitting, and away you go. On most polyethylene tanks, your best bet is to spin-weld fittings into place. For the VTS tanks, you can have VTS spin weld the fittings in for you, but you have to be very confident of where you want them to be. I actually constructed faux-tanks the same size as the VTS tanks out of insulating foam so that I could play around with them and figure out exactly where I needed them and where the drain/vent holes ought to be spun in. This worked out quite well. I have heard of other people ordering the tanks with no additional spun fittings, and they decide where they want the fittings and then take the tanks to a local RV place and have the fittings installed. So again, its a custom job, not really an off-the-shelf solution, so it takes some careful planning (to order your tanks with the fittings in the right place).

[moparjohn]

Do you have to open the floor of the trailer to install these tanks or can you go in from the bottom? I realize you will have to access the drains into the tanks from above. which is preferred drain grey into black and then out, or separate exits for both? Thanks John

[dbj216]

A 71 Globetrotter that doesn't need much work is a rare trailer indeed. Airstream archives shows the 71 with a rear bath, above floor black tank. I wonder if the sewer hose connection is on the bottom and pointing down at the rear of the trailer like my son's is. This is not a the handiest.

I think all modern Airstreams have below the frame rail sewer connections, usually, but now always, behind the wheels. As mentioned above, some folks like the skinny tanks between the frame cross members, and some hang a larger tank to drain below the frame rails out the side. Here is a photo of my 86 sewer connection, and a photo of an 05 single axle Bambi Airstream with a very low sewer connection.

I like tanks that look like a "T" so they can be hung from angle irons. I like to drain them below the frame rails and out the street side of the trailer.

To install a gray tank under your Globetrotter, you will need to drop the belly pan and insulation, figure the best frame bay (between cross members) for the gray tank, figure a mounting method and a drain manifold with blade valve. Then you will need to plumb ABS piping from the galley sink, shower bath, and bath sink to the new gray tank. You will also have to figure a vent for the tank. Yep, it is a significant project. I'm installing a new gray tank in my 75 Overlander this winter. I'm almost done with that project.

David

[Bauxter]

Anyone know anyone in Ohio that can spin weld a few fittings on my new polyethylene tanks? If you do, please PM me. I can't find a single person to do it.

Should I be so leary of those rubber grommet connections?



So why are ABS tanks so expensive now?? My poly tanks were less than 1/3 the price of ABS