This is my entry for the #vanlife contest.
It will also give you an alternate use for your tire compressor.
I don't live in my van but I work from it every day, I regularly work on construction sites and quarries. It is nice to have access to warm running water to wash my hands and clean down my gear.
This device would also be really handy when staying in your van or camping.
WARNING: This instructable involves a heater, this unit has no thermostat so will not stop heating the water without intervention.
Also, the container is pressurized with no relief valve, failure to monitor the pressure in the container may result in rupture and possible injury.
Step 1: You Will Need
For this instructable you will need:
- 20L water butt
- Bicycle inner tube
- 12V immersion water heater
- Utility shower
- Epoxy resin
- High temperature sealer
- 12V power pack with an air compressor
Step 2: Prepare the Pressure Cap
As an alternative to a water pump, I opted to use my tire compressor to pressurize the vessel.
Starting with the inner tube, cut out a section around the valve.
Trim down the surrounding rubber until the valve fits inside the lid of the water butt.
Drill a 9mm hole in the center of the lid and insert the valve.
Using epoxy, bond the valve into the lid.
Use a spacer and a clamp to apply pressure, allow the epoxy to cure before applying any pressure.
Step 3: Install Water Heater
Remove the installed tap by unscrewing it.
There is a backing plate in the hole which has to be cut out.
The water heater is too large to fit through the hole from the outside so it needs to be fished through the neck of the container using a heavy electrical wire.
The heater is pulled backward through the hole and fixed in place with some high-temperature silicone. Again this should be left to fully cure before pressurizing the container.
Note: the sealer used here is not food grade so the water from this unit is not suitable to drink, there are sealers that are food safe if you want to be able to drink the water.
Step 4: Install the Tap
Drill a 10mm hole in the side of the container, I placed this at about the 5l mark on the container. This allows the heater to remain submerged as to expose the element could result in burning it out.
The tap can be turned off to allow you to remove the hose during transport and filling, making it a little easier to handle.
Step 5: Test
I filled the tank to about 10l for the test.
I hooked the heater to the 12V outlet on the power pack and allowed to heat. It took about 30mins for the water to become noticeably warm.
I then connected on the air line and pressurized the container. I worked in steps stopping to test pressure at 10, 15, 20, 25 ad 30psi. The container swelled significantly after 25psi. At around 20 the pressure from the outlet was pretty good.
Please note you should heat the water prior to pressurization as hot water will further expand and may push the pressure to the point of rupturing the container.
Step 6: Problems, Thoughts and Future Ideas
In the early stages of testing, I over pressurized the container and sprung a few leaks. Releasing the pressure and emptying the tank, repairs were easy and I got to know the limits of my tank.
The tank needs a temperature gauge, I was thinking something along the lines of the stick on thermometers for aquariums but most stop at 40 deg C, if they go beyond this they just show black. I note this as during one of the tests I forgot that I had left the heater on and there was only about 6l of water in the tank when I released the water it was very hot and not at all nice to have pour on my hand!
As the pressure in the tank drops so does the outlet pressure. To counter this I ran the compressor constantly but if you are not siphoning off the water pressure you need to stop the compressor to stop the tank bursting. If there was a pressure release valve this would take care of itself.
Runner Up in the
Outside Contest 2017