AIRSTREAM RENOVATION: Repairing the Water Holding Tanks

Let's talk about the process of inspecting the water holding tanks on a vintage Airstream

i only have the fresh and the gray water tank. I threw the black water tank out because, honestly, when i took it out of the trailer it was half full of crap *literally* and i just didn't want to deal with it so i just threw it away and  that's just really gross anyway.  plus we're not going to be needing a black water tank because we're going to go with a composting toilet! So that's exciting.

So after inspecting both tanks, and realizing how expensive new tanks would be, I decided that these tanks are in good enough condition to keep and just need a little cleaning up. The only repair I needed to make was to the inlet fitting on the fresh water tank. It has split at some point in the past and the previous owner had to make repairs. I could tell because it was covered in epoxy sealant.

The other issue I had to deal with was just cleaning out the inside of the tanks. Which was way harder than I thought!

The gray tank had some overflow from the black tank, so yeah, that was disgusting! I did my best to blast it all out with the pressure washer, boy is it hard to get around the corners. I rinsed both tanks out with some vinegar water, which is supposed to kill bacteria and sterilize it. The fresh water tank had some orange residue at the bottom of it, not sure what it is or what it's from but I blasted the heck out of it with the pressure washer, and I least got any loose residue off. The tank still has a hint of that color but the water is coming out clear so I am not too worried about it.

Plumbing parts

I ordered all new hoses and fittings for both tanks.

Some parts I found at Vintage Trailer Supply, such as the corrugated inlet hose and vinyl hose for the fresh water tank. And I can't remember or find the emails for where I ordered the rest of the plumbing, the drain pipe and the Valterra valve for the gray water tank. I'll update this when I find it... my life haha.

So I measured the fitting on my tank and figured it would be pretty straightforward, but apparently it's not! The fitting measured at 1.5 inches inside diameter so I ordered the 1.5 inch elbow tank adaptor. But the adaptor was 1.5 inches outside diameter or something because it was too big, and the one I actually need was 1.25 inches.... anyway, plumbing measurements are not as simple as other things... I spent an entire day running around and scrambling to find parts that would work and eventually ended up with a solution that involved 3 different fittings. and luckily it still (barely) fit in the tank pan.

After I got the fitting in, I now needed to seal up that crack. I used some PlasticWeld by JB Weld and it worked like a charm. After it dried, I ran some water through to test it and no leaks! Finally, we are getting somewhere.

Heaters and Monitoring System

I also decided to go with electric tank heaters instead of running a vent hose from the furnace. I got these Thermaheat Tank heating pads from RVUPGRADES.COM, you just peel and stick them onto the bottom of the tank. Hopefully they work, because I have not been able to test them out!

I am also super stoked on the new tank sensors that I got from, I went with the SeeLevel II system which now comes with "circuit board" sensors that you can stick to the outside of the tank, instead of the old sensors that were spin welded into the inside of the tank. No more needing to clean the sensors! 

Fixing the tank pans

The tank pans, which hold the tanks in place, were in pretty bad shape. One if not both were definitely hit by a rock or two. The fresh water tank pan was the worst. Luckily I had some connections and Matt over at Impact Auto Body in Hailey, Idaho hooked me up and did a quick fix on it and got it all straightened out for me! The tank pan wasn't as bad and I was able to hammer it out myself. I cleaned them all up and painted them with POR15. I went with the POR15 since I didn't have any of the Eastwood Rust encapsulator left, and I didn't have time to order it in, so I picked up some POR15 in Twin Falls. I have to say I am pretty impressed. It's a really tough paint!

and yeah, I kinda forgot to get a picture of the finished repaired pans, so... oops!

Installing the tanks

Now that everything is fixed up and ready to go, it's time to install the tanks onto the chassis. Before I put the tanks into the pans, I laid down some of the hemp insulation about an inch thick for the tank to lay on top of. This is more for padding and protection than temperature, but I am sure it will help a bit with that too.

the pieces of the gray water tank drain

The tank and pan combined are rather heavy so I needed help with this part of the process. Lacie helped me make sure it was all lined up properly and we used the car jack to help us lift it up, and we shoved a stack of plywood underneath to help hold it up. The fresh water tank has to go in from the bottom, as there is a cross beam welded in on the top of the frame, but the gray water tank can go in from the top meaning, I don't have to have it in the pan when I mount it up. that makes it a little easier.

Most of the original screws were rusted out, and some of them even broke off and were stuck inside the chassis. And instead of trying to deal with lining it up perfectly with the old holes, I just got some self tapping screws and called it good. They did the job perfectly and cinched it up nice and tight. I also lined it with some Butyl tape before I put it on to help seal it so no water or dust/dirt can force it's way in there.

I stuffed some more insulation around the sides of the tanks once they were centered in-between the frame bars. Again for more padding and protection and to keep the tanks from shifting.

Finishing up the Gray water plumbing.

Now that the gray water tank is installed I can get the drain in place. Originally, there was a "T" in place connection both the black and gray tanks to one drain, but since I only have one tank now, I just need a simple "L" to go from the gray tank to the hole in the pan. I used various parts and fitting to make it all work. Our gray tank drain fitting is 3 inch diameter so I uses all 3 inch pipes. Most of the fittings are Valterra, including the valve.

Because I won't be needing two valves I wanted to seal up the extra hole in the tank pan that was there for the black tank valve, for this i just got a thin piece of sheet metal to go over that hole, as well as fill in the rest of the hole that the drain pipe went out. Just to keep the critters out. For the gray tank valve, I also sealed that up but since the valve rod will be moving back and forth it needed to be something flexible and still give it a good enough seal. I found a 6x6 inch rubber gasket at Lowes and pokes a hole in it where the rod would go through and shoved it onto the rod. Works great! I also needed to get an 8 inch rod extension for the valved because it wasn't long enough to reach out.

And that's pretty much it! It was a long and stressful process, mostly because I was in a rush to get it all done before winter hit but it's now over and done and I am so stoked!

In the next post we will go over preparing the subfloor with cutting it to size and sealing it to protect it from water damage.

Until next time!

About the Author
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Ben Figueiredo

I make a living as a filmmaker & Website Designer, Telling Stories, creating content for businesses, entrepreneurs and even couples getting married. As a Five on the Enneagram, I love learning. Absorbing as much knowledge I can. I am into Biohacking, holistic wellness, and Rewilding so that I can be the best version of me to enjoy life with my family connecting with nature, our community, and God.

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