How To Make A Portable Grey Water Tank For An RV

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RV camping can be as DIY-oriented as you make it. No matter what, though, you’re going to have to dump your used water out. Instead of breaking camp every time you need to get rid of your waste, though, consider the other disposal methods you have on hand. For example, ask yourself: how could you make a portable grey water tank for your RV?

The best way to make a portable grey water tank for your RV is to modify one of the strongest sealed containers you have on hand. Trick this container out with wheels, a handle, a vent, and a sealed hose, and you’ll have your very own DIY grey water tank. 

You’ll want to make sure your water tank is as sturdy as possible before putting it to good use. Once you’re able to wheel your tank back and forth between deposit stations, though, you’ll find that your RV camping trips become a lot simpler. Keep reading to find out more about grey water tanks.

recreational vehicle parked at a camping ground with kitchen setup just outside. How To Make A Portable Grey Water Tank For An RV

How To Make A Portable Grey Water Tank For An RV

Grey water tanks collect the water that you use when showering, cooking, or washing dishes in an RV. You’ll need to dump out your grey water tank from time to time on longer trips to ensure that your ride stays as clean as possible.

Transporting a grey water tank isn’t all that easy, especially when it’s full. Portable accessories, including handles, wheels, and harnesses, can spare your back while making it easier than ever for you to move your tank to and from a dumpsite.

view of proper disposal of gray water and waste water from a camper van at an RV park

Your Materials

When building a portable grey water tank, your supplies should include:

  • A water-tight container of your choice, ranging between 7 and 40 gallons
  • C-pap tubing
  • An elbow joint made out of PVC 
  • A rain drip end-plug
  • The appropriate adapters
  • Additional PVC pipe
  • Waterproof silicone and tape
  • Sandpaper
  • Scissors
  • Measuring tape
  • A drill 

The Process

To begin making your tank, you’ll want to:

  1. Set your tank upright.
  2. Draw a small circle towards the bottom of your tank (four inches up or fewer) where the drain will eventually go. Leave enough room between the bottom of your tank and the pipe to allow the elbow joint to sit comfortably.
  3. Cut out the circle using your drill, smoothing it with sandpaper or other appropriate materials.
  4. Fit one of your adapters around your cut hole to seal it.
  5. Fit your PVC pipe into the fitted seal, leaving two inches outside of your tank.
  6. Attach your elbow joint to the exposed pipe from the inside of the tank.
  7. Weld the two pipes together with silicone.
  8. Attach the c-pap pipe to the exposed PVC from the outside of the tank.
  9. Connect the c-pap pipe to the exposed PVC using either a zip tie or a silver brace.

With this, your grey water tank is complete. To add the portable features, you’ll want to use a drill to safely attach a handle to the top of your chosen container. If you want to build a harness for the container to sit into, you can craft that around your container, attaching wheels to the bottom. As you build this container, however, make sure that your water tank can still comfortably fit into the space you have for it beneath your sink or shower.

Alternatively, you can attach wheels directly to your grey water tank. The easiest way to do this is to build a small rack beneath your container that you can attach to said container, courtesy of seals or screws. Fix the wheels to this rack alongside a handle, and you’ll be able to transport your grey water tank to and from the dumpsite with ease.

Are There Unsafe Grey Water Tank Materials?

There are some materials that you’ll want to avoid when making your portable grey water tank. While traditional grey water tanks are made out of resin, this material can be dangerous to use if you don’t have the right experience. Resin that doesn’t set properly can start to leak when exposed to the chemicals in your grey water.

It’s often easiest to create a grey water tank by using recycled or thrifted materials. Before you put your drinking and bathing water into these containers, though, you need to make sure that they’re clean. Gas cans, for example, are among the most effective DIY grey water tanks, but only when they’ve been thoroughly sanitized.

What Are Grey Water Tanks Made Of?

Store-bought grey water tanks are made out of polyethylene resin to create a smooth finish. These grey water tanks are rotationally molded to ensure that there are no weak spots within the make, thereby preventing leaks.

If you’re making your own grey water tank, it may be best to leave the resin and rotations for a point later down the road. There are other materials that can carry your water for you just as well. These can include:

  • Steel drums and barrels
  • Plastic drums
  • Aluminum gas tanks, cleaned or never-used

You’ll always want to make sure that whatever material you opt to use for your grey water tank has been treated and cleaned. While these tanks will take on your wastewater, you don’t want any dangerous runoff impacting the natural environment around RV dump sites. Be sure to fit your grey water tank to your RV as well so the amount of water you have doesn’t weigh down your ride.

How Do You Make a Grey Water Tank?

Professionals make grey water tanks en masse. These tanks, as mentioned, are made out of resin that is poured into an appropriate mold. Manufacturers rotate these molds to ensure that the resin makes it all the way through the mold as it solidifies. When the make is complete, manufacturers can remove the completed grey water tanks from their molds, fit them with any additional branding, and then send them on their way.

Even if you don’t have access to a resin mold or conventional rotator, you can still make your own grey water tank. You will, however, want to take a DIY and thrift route to make this process as simple as possible. Look for recycled or refurbished tanks that fit within the make of your RV. Be prepared, too, with the right tools to do some soldering, cutting, and sealing.

If you want your grey water tank to be portable, you need to fit it with wheels and a handle. You can do this by creating your own harness or by fitting the appropriate accessories to your tank.

How Large Does My Grey Water Tank Need to Be?

RVing In The Mountains In Class C Motorhome Landscape At Sunset

The size of your grey water tank should vary based on your personal needs. When you create your own grey water tank, you’ll have plenty of opportunities to customize it, ensuring that the tank lasts for as long as you need it to while remaining compatible with the RV itself.

With that in mind, be sure to consider the following factors:

Your Family’s Size

The number of people you have in your RV should directly factor into the size of your grey water tank. The more people you have in the same space as you, the more room you’ll want your water tank to have.

Note that children often use more water than adults because they’re still learning how to conserve resources. As such, you’ll want to plan the size of your DIY grey water container both with the age and number of your travelers in mind.

The Length of Your Trips

How long, on average, do you spend in your RV? Where, too, do you plan on resting? If you go on shorter trips and divide your time between camps and hotels, then you may not need a large grey water tank. If you tend to rough it for an extended period of time, though, then your water tank needs to hold you over for several days at a time.

The Size of Your Waste Tank

Above all else, you want your grey water tank to be compatible with the rest of your RV. If you craft a grey water tank that is larger than your waste tank, there’s a chance that the uneven distribution may cause a leak in your ride. Measure your waste tank before making any modifications to the containers you have on hand, and you’ll have a better chance of protecting your RV’s other utilities.

How Long Will a 40-Gallon Grey Water Tank Last?

A 40-gallon grey water tank carries a substantial amount of wastewater. However, the amount of time that your grey water tank lasts will vary based on your circumstances. If you have children with you who like to take long showers or who run your sink for several minutes at a time, then you’re going to run out of room in your tank sooner rather than later.

That said, if you have adults on-site who’ve traveled in an RV before, your 40-gallon tank should last you between 8 to 10 days.

recreational vehicle parked near the beach. How To Make A Portable Grey Water Tank For An RV

Prepare For Your Next RV Trip with a DIY Grey Tank Project

RV camping is an exercise in creativity. The more of a hands-on approach you choose to take, the more control you can exert over your experience. If you’re sick and tired of breaking camp every time you need to get rid of your grey water, consider what a portable, DIY grey tank could do for you. So long as you have strong materials and waterproof sealant on hand, you can make the care and keeping of your RV a little simpler.

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