Successful gray water retrofit???

[blrpix]

Has anyone done this successfuly?

I want to do this to my 1965 20ft Globe Trotter.

Fitting a tank under the belly does not seem like an issue..that said here are my concerns:

1) The position of the tank...closer to the axle the better I would think?

2) That said the bigger concern is the slope from the lowest point (shower drain) to the tank...I can almost envision a flat run, but to get any slope would vastly diminish the tank capacity...correct?

Any ideas are appreciated.

[thenewkid64]

Originally Posted by blrpix

Has anyone done this successfuly?

I want to do this to my 1965 20ft Globe Trotter.

Fitting a tank under the belly does not seem like an issue..that said here are my concerns:

1) The position of the tank...closer to the axle the better I would think?

2) That said the bigger concern is the slope from the lowest point (shower drain) to the tank...I can almost envision a flat run, but to get any slope would vastly diminish the tank capacity...correct?

Any ideas are appreciated.

I am in the process of doing a add on tank to a trailer with a 6 gallon grey. as a plumber friend told me water WILL find it's level. If the top of the tank is below the level of the water in the P trap and you vent the tank it will flow into the tank no matter where the pipe enters the tank. It may start to flow slow as the tank gets full though

[rluhr]

Originally Posted by blrpix

1) The position of the tank...closer to the axle the better I would think?

I own a 68 Caravel fitted with a gray tank. The tank is slung from the axle rearward (24 inches). The tank is 48 inches wide and 7 inches deep, for a capacity of 34.9 gallons. (If you're going to do it, you might as well put in a nice big tank!)

The major catch is that a full tank of this size will alter your tongue weight, and may choose to detach itself during travel. Mine weighs almost 280 lbs when full, enough to overload the Caravel's axle. So it is a mandatory checklist item to dump the gray tank before travel. If you are conscientous about this, you can eliminate a lot of potential design problems, too, because you only have to design for short-distance travel with the extra 200+ lbs. (typically the distance between the campsite and the dump station).

I didn't do the original install, but I've re-built the mounting system. My tank is secured on the front edge by simply slipping the front flange of the tank between the axle and bellypan. In this way, the front of the tank is supported by the axle directly.

The rear of the tank is supported by a 48" piece of angle iron (again, holding up the tank's flange). The angle iron is bolted into the frame at either end with beefy, coarse-threaded bolts. These bolts are the weak spot -- choose the wrong type and they will rust and break, or strip out. I put Loc-Tite on the threads and also orange marker paint show that I can readily tell if they are loosening.

As further insurance, my tank is strapped front to back. But this is like putting on safety chains -- not something you want to rely on except for redundancy.

Having a gray tank is really great. No blue tank hauling, and you can go anywhere. We just got back from a place on the beach where only "fully" self-contained RVs are allowed. The manager took a look at my plumbing to be sure, because this beachfront state park is ecologically sensitive. I would have been disappointed if we had been denied access for lack of a gray tank.

Good luck with your project.

[markdoane]

Blrpix,
I have my new gray tank located ahead of the axle, with about an 8ft run from the rear vanity to the gray tank. I put the drain pipe in with a 1/8"/ft slope. I know it isn't much, but I figure if it's a problem I can lower the tongue of the trailer an inch when I take a shower. I also put in a back flow valve to keep water from sloshing back into the shower pan while travelling. I can also fit a drain plug in the shower drain if necessary.
In this picture, the drain line is about 12" to the right of the left side frame rail. (the blue tubing is electrical conduit).

[Chuck]

Originally Posted by rluhr

Having a gray tank is really great. No blue tank hauling, and you can go anywhere.
.

...and you can always borrow your neighbor's, should the need arise

Rich, do you have any idea what the origin (manufacturer?) of your tank is? been browsing around trying to find something suitable, and can't find anything that'll fit, at least inside the frame space. If I want to go that way, I may need to contact someone we know that'll make one out of fiberglass. (anyone got any opinions on a fiberglass tank??).

Don, how about you: is that a custom job, or is that an "off the shelf" tank?

I found a plastic fabricator locally, and sent them off an email for a "ball-park" figure on making a custom tank. just e-mailed me back: $410!! makes my $150 blue-boy seem so much more attractive

[markdoane]

Originally Posted by chuck

Don, how about you: is that a custom job, or is that an "off the shelf" tank?

Mine is 28 gal, about $120. from Accutank.
HOWEVER- The tank was exactly 24" wide. Not a problem, as I was relocating two of the crossmembers, so I made the space 24 1/2" wide. However, it might be a problem for normal frame spacing.

Knowing how these tanks are made (rotational molding), you might be able to talk the manufacturer into putting a shim or spacer in the mold to make a one-off tank 23 3/4" wide. Won't know unless you ask. They can also adjust the amount of 'shrink' by how they cool the tank after it is molded. Pretty risky, and all the risk would be on your nickel.
To get anywhere with this you need to talk to the guys that make the tanks, not the salesman who answers the phone. It helps if you work for a company that might order dozens of tanks someday.

[rluhr]

Originally Posted by chuck

...and you can always borrow your neighbor's, should the need arise

Hey, that was the first time I've ever used a blue tank -- really! I was just curious about how it works. Yeah, that's it -- I was CURIOUS.

Originally Posted by chuck

Rich, do you have any idea what the origin (manufacturer?) of your tank is?

I think there is a manufacturer label on mine but I won't be able to check it for a few days. The trailer is 10 miles from me and the rain is pouring down. If we get a break tomorrow I'll go over and look for the label. I remember trying to find them on the web once, so I know they don't have a website.

My gray tank is polyethylene, like your blue tank.

Try a web search on water tanks and you'll find a few manufacturers with standard sizes available.

[aztlanco]

blrpix;
There is an interesting article by Stuart Natof in The Vintage Advantage Newsletter (the vintage Airstream club). Issue # 1,Q2 Vol. 11 2004.
The article has pictures and shows how this guy made his own holding tanks for his '64 Bamby. It also shows valves, hangers, skid plate and bellypan.
Good luck!
Ernie WBCCI #4636
'58 Traveler
'50 Ford F-1 tow vehicle (350 Chevy engine)