DIY - How to make a car top shower.
You might be wondering why we would post information on how to make a car top shower since we sell a commercial version. The reason: There is not much information about the differences between a DIY Road Shower and a Road Shower 4. There are many difference, from capability to safety. We think that if you know the facts you will choose a Road Shower 4. If you want to make your own after reading this you will be making an informed decision. Also, just so you know, Road Shower was invented first and made the roof top shower famous, and the DIY versions came afterwards.
Parts needed to make your own Road Shower. Cost around $125. - These parts are not safe for drinking water or safe to be pressurized, and we do not advocate making one yourself. We show this picture that is on Kombi Life for comparison only.
For detailed directions check out REI Coop Journal and Kombi Life.
Let's compare now.
Road Shower 4S - $330 with shipping. - Time. Buying 1/2 hour. Unpacking and installing. 1/2 hour. $12 in time. Total cost $342.
DIY Shower - Around $125 in parts. And that doesn't count pressure relief valves or a bike tray to mount it on. Time - reading and planning - 2 hours. Shopping 2 hours. Laying it out and cutting and drilling - 2 hours. Gluing, testing, re-gluing. 1 hour. Mounting - 2 hours. Total 9 hours. That doesn't count starting over if you screw up. Add 7 hours for that and buying more parts. What is your free time worth? Let's say just above minimum wage. $12 per hour. So $108 in time. Total cost $233. If you are a fast worker, maybe you could do it in 5 hours. So knock off $50 if so for a total of $183.
Cost savings. $109 - $159. (If you didn't screw up. If you did and have to start over, you are now breaking even.) -
The Road Shower 4 can safely be pressurized to 65 PSI. It has a built in air chamber, so you can pressurize it once and drain the tank. Shoot a spray of water about 60'.
Kombi's shower runs on gravity. You can see the gentle spray in the lower left. They said the nozzle needs to be low to the ground, or there is not much pressure. The also said, "WARNING: If you are going to pressurize your shower with air you really should have a pressure relief valve installed! The plastic one shown in this video won't withstand 18 PSI."
What they did not tell you is that it is actually very dangerous to pressurize PVC, ABS, or any plastic pipe with air. Pressurized air can cause the pipe to explode into sharp shrapnel, and can hurt and possibly kill someone. The pressure rating for the PVC pipe is for water not air. Unlike water, which is incompressible, air is very compressible, making it hydraulically equivalent to a large mechanical spring. It is actually illegal to use air to pressurize PVC in the workplace under OSHA regulations.
Here is a quote from this website: https://www.pvcfittingsonline.com/resource-center/using-pvc-pipe-for-compressed-air/
"Despite how much it can do, there are certain jobs that PVC pipe just can't handle. One of those jobs is compressed air. When using PVC pipe with compressed air, you run serious risks. The most dangerous of these is that of explosion. If put under stress that it cannot handle, PVC pipe can explode, sending plastic shrapnel flying. There have been numerous cases of this happening in compressed air applications."
Road Shower uses built in T-slots, so mounting is easy and it stays secure. There is a T-slot on the bottom and one on the side for multiple mounting options.
The DIY units need to be secured with rope, bungis, garden hose, or something else. They are round, so they tend to roll around, unless you make some kind of cradle for them to set on.
Road Shower is made from aluminum, which is a good conductor of heat. It is powder coated black. It can heat water much faster than black PVC or ABS. Plastic pipes are insulators, not conductors. It will take them a long time to get to the 80-90F range and it needs to be a really hot sunny day. Road Shower can heat water 10-15F per hour, reaching a max heat of around 100-110F in 2-3 hours. PVC or ABS will hold the heat longer after the sun goes down. However Road Shower has an accessory that covers and insulates it, in order to hold the heat for hours. DIY models will not heat much when the days are around 70F. Road Shower 4 will.
Road Shower 4 comes with a built in air chamber. DIY models will need to be pumped several times to drain the tank. So you only have to pressurize it once and you can drain the tank. It also has locking loops so you can use a cable lock to lock it to your rack. Not that someone would steal a DIY model, just saying. Road Shower 4 comes with accessories, such as a flex neck shower head. Road Shower uses aluminum which is non-toxic, and food grade hose, so you can use it for drinking water. You should not drink from ABS pipe.
Road Shower 4 is superior in Looks, Pressure and Mounting and Heating. DIY Shower is less costly. However, Road Shower 4 should last you at least 20 years. The DIY's will wear out long before that.
If you want to make one out of aluminum pipe and weld it and powder coat it, you will spend around $400. And it won't have slots for mounting bolts.
Historical note: Some of you might know that when we first started making Road Showers in 2012, we made them with ABS plastic pipe. You can see them here. However there were some important differences between those and the DIY units. First we had 2 pressure relief valves. One opened at 8 PSI, and if that one failed the next one opened at 10 PSI. So even though pressurizing plastic pipe is dangerous, we knew we were selling a safe product. Each of those valves costs about $10. Also we had a clear plexiglass window that was painted with black epoxy swimming pool paint on the inside. This increased the heating by 200 %. The cost of plexiglass and paint - add $25. In addition, we did not want them rolling around on the roof rack bars. We strapped the tube to a bike tray which then mounted to a rack via the T-slot on the tray. Add $45 for the bike tray and $12 for the mounting hardware. So if you wanted to make one like the original Road Shower, which was a good product, add $102 for the extra parts and 3 more hours of work.