H2OT - Rooftop, pressurized, solar-heated shower/sprayer using ABS pipe. DIY

After using the shower for 6 years now, I can say that this is the best camping gear I have made. We use it every trip and it is still going strong with no problems at all. Here is my response to the most frequent questions I receive about the build.

*ABS VS PVC*
I used ABS ( acrylonitrile butadiene styrene) pipe and not PVC (polyvinyl chloride). I used this for several reasons. ABS is much more resistant to impact, it is cell core meaning it will hold the heat better, it is more readily available in my region, easier to assemble (no primer required) and it is cheaper (up to half price) than PVC.

*FILLING AND USAGE.*
It is best to slightly elevate the front of the tank when filling and using the shower. This way, air does not get trapped at the drain end, reducing the capacity. It only needs to be 1 or 2 degrees elevated. This could be done by parking slightly uphill or using a thicker foam block on the front.

*ALWAYS TRAVEL WITH THE TANK FULL OR EMPTY*
Any partially filled tank will act like a water hammer when you hit the brakes. This could launch your shower like a missile, which would not be good. A full tank is similar to a solid mass, nothing will shift inside when braking hard. So, fIll the tank right to the brim and do not travel with a partially filled tank.

*PRESSURE RANGE.*
I pressurize the tank to 30 psi and shut off the compressor. When the pressure drops to 10 psi, I turn it back on and pressurize to 30 psi. 10 psi is still ample pressure for a shower. An upgrade from what I have would be a compressor with auto shut-off.

*PRESSURE VS. VOLUME.*
Water does NOT compress. As a result, if the tank is filled to the brim there is no room for air. Thus, the pressure will drop immediately from 30 psi and you will have to turn the compressor back on. As the water is used, the volume of space available to fill with compressed air increases. By the time you reach half a tank, you can go to empty on one recharge.

*FILLER SEAL*
The 2-inch filler cap has a silicone seal that prevents air from leaking out through that joint. I used a LESSO 2 In. ABS Male Plug MIPT which comes with the gasket.

*PRIVACY SCREEN*
We use a pop-up shower shelter right up against the side of our truck. We just route the hose over the top. We stand in a big Rubbermaid container to catch most of the water so that we do not have a wet and muddy mess. https://www.amazon.ca/gp/product/B015HQ6CTO

*TEE INSTEAD OF HUB*
You could use a 4” x 4” x 2” Tee instead of drilling the 2 “ Hub directly into the pipe It would add a bit of weight, and cost and not look as neat, but it will work just as well

*DRAIN AND AIR VALVE PLACEMENT*
I put both the drain and the air valve on the same end to protect the air valve from being damaged if the end was to hit something. Plus this allows me to store the tank vertically on the front end when not in use.

*ABS SOLVENT CEMENT IS NOT GLUE.*
The parts are not glued together, they are chemically welded using solvent cement. This literally metals the ABS pieces together. If done correctly, the joint is stronger than the pipe itself.

*HAND PUMP*
It would be very difficult to pressurize the tank with a hand (i.e. bicycle tire) pump. The volume of the tank is greater than the volume of a typical car tire. How long would it take to inflate a car tire this way?

*GRAVITY FLOW.*
You cannot use this mounted on the roof of your vehicle and expect gravity to generate the necessary pressure. Water pressure from gravity alone is called "head" and is measured in units of distance. 1 PSI = 28 inches of head. That is, if the spray nozzle is 28 inches below the tank, you will get 1 PSI. Assuming you are standing up and are at normal height and the nozzle is also at head height, you will get next to zero pressure.

*THREADED SPIGOT*
Before threading the spigot (Drain) into the end cap, I heated the brass threads up with a propane torch. This slightly melted the ABS and made threading it in very easy. Once cold, it formed a perfect seal.

*CONTINUOUS USE*
We do not have the spray nozzle on other than for initial wetting and then rinsing. This is key to preserving water and how two of us can have showers and still have water left in the tank.

For information or to contact me about my videos, I can be reached at http://camerasutra.ca