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Home Made RO/DI Car Wash with real pressure.

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SabrToothSqrl

Active Member
Dec 5, 2014
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Small back story:
At my last house, and now my current one, the water DESTROYED two cars. Detailing shops and thousands of dollars later could not fix the water spots.
5+ years of $600/year (2 cars) car wash unlimited pass: zero water spots across 4 cars.

However, washing my car, in my driveway, like I assume for many people, is therapeutic. It's your car, you want to keep it nice. I was tired of the hassle of hand washing in a bay, and funny looks from chumps. Then trying to get it 100% for the drive home, where it would obviously get dirty within seconds.

After MUCH research and finding a few off the shelf solutions ($700+) that would offer what I was looking for... or close to, but not quite (not enough volume/pressure). I decided to build my own! I'm that special kind of person who likes a challenge that keeps him up and night and makes himself regret things or bleed on occasion.

So, I wanted wash my car at home. Problem: Well Water. (I got to learn a LOT about water) (But my advice is only worth what you've paid for it, so it's all AT YOUR OWN RISK).

Well water: 60-80 PSI on the pump (I cranked that baby long ago). Hardness rating: 13. 135 PPM TDS.
Parts Per Million, Total Disolved Solids. So for every 1,000,000 gallons of water, I have 135 gallons of 'crap'. (most likely calcium I think).

Flows to a 5 micron sediment filter. Followed by a water softner, followed by a 1 micron to the house.

Output: 0-1 hardness, 135 ppm TDS

So, the house water is ecologically sounds and 100% healthy for human consumption.

However the water destroys anything glass / car. Shower door? destroyed. Car paint? Destroyed. Car glass? Must be replaced to be fixed.

So... time for the only thing you can do. Reverse Osmosis. (links to everything I can remember at bottom).

75 GPD RO/DI system. + Shut off float valve. = makes RO/DI Water (De ionization).

Water comes in at the above, hits a 5 micron filter, hits a carbon filter, then RO membrane.
Water comes out a 1-3 PPM TDS. (pretty good!) 99% reduction.
Water hits the DI system, and comes out at ZERO TDS.

Water fills a broken (wheels broke) 64 gallon bin to the limit of the float valve.

Water then goes to the Harbor Freight 1 HP 30/50 PSI Shallow Well Pump with tank.

Water exits via 3/4" PEX to a 1/4 turn hose nozzle out the side of my house, to the driveway to be used to wash my cars.

I still have a small leak at the in and or out of the pump Blue Monster tape is awesome for plumbing.
Shark Bites are awesome. The smell of PVC glue takes me back... I used a union so I could move the water tank and pump for service issues.

I have not finished the wiring for the pump yet, but just used extension cord for testing. Washed my X last night and it shows ZERO water spots today. Pressure from the setup is good. My hose nozzle sucks, so I need one of those now...

Anyway, I'll post the links next. if you're neurotic like me you can now have a clean car, if you want... it's my little unpaid hour of therapy...

89392282_294421778198490_5527892663962959872_n.jpg 89499379_604141120167238_2642268132516823040_n.jpg

Ignore the water the ground lol that was a mistake.
 
That's interesting and a cool setup. I'm a homebrewer so I too have dealt with treating my home water to achieve different results.

But as a professional detailer I'm going to sound like an ass no matter how I say this so please don't get offended, I just mention the following to further the conversation...
I know you said you enjoy problem solving and tasks like your water project, but I have to ask why not just dry your car off after you wash it? I don't care how hard the well water is in your area, as long as you don't let it evaporate on the surface it will not leave mineral deposits. Of course you must already know this and have a good answer, but I feel like it needs to be asked for others reading this post, and to further this kind of discussion in a topic that I'm interested in and have significant experience.

Secondly, a rinseless wash process like OCNR also eliminates the problem of hard water mineral deposits on cars, and uses far less water in the process. Since you may choose to wash only one panel at a time you can wash your car in direct sunlight without worry of the solution evaporating too soon and causing spots.

As a side note, I'm sure you already know this but expect almost any metal components downstream of your DI system to corrode relatively quickly.

If my comments don't reflect the therapeutic nature of how much you enjoy washing your car then I totally understand, and please disregard.
 
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No worries, polite discussion is good. It's not a project / fit for everyone, just what worked for me.

As to drying it? I have. OMG have I tried. Been there, done that. In the parking lot of the local car wash in direct sunlight with a black car. (Not really ideal, I'm tired of it, and sick of it). At $600/year, this system will pay for it's self in well under a year. Not to mention time and miles saved. So my ROI on my RODI (get it?) should be around $500/year, starting year 2. (only real cost is DI Resin). (wife pays the electric bill ;))

So, even if I was to spend an hour at the car wash parking lot, (In addition to the 20 min I am working as physically fast as I can to actually wash it) (the limit of the 'unlimited' pass). (And I have)
Then it's a 8 mile drive home. During which water will, without question, end up coming out of the mirrors, roof, doors, rear hatch, etc. Then I get not only water streaks, but cut grass, dirt, road debris, a million other things will dirty the car beyond belief in only 8 miles. God forbid there is any water / puddles on the road, then you're really screwed... (I'm so picky that even a speck to me feels like I failed).

ALL
that hard work to feel like "why do I bother?"
What have I done so wrong that I can't even have a clean car for a few hours?

When I wash and dry it at home, I can park it in my garage. But being a black car, it will be dirty again within 2 hours... because... black car. I tell my wife not to look at it, if you don't at it, then it's not dirty, right?

I get what you are saying, but I'm not sure anyone could dry it fast enough to not get spots, consistently, and 100% of the time. Anyone is welcome to wash their car with my well water if you want to test :) I'll grill up some burgers and watch :) But honestly, who wants to wash a $85,000 car, knowing it's bad water? or a $50k car? (whatever a 3 LRAWD is now) with the same said bad water? That would be like trying to run your lawnmower around your child's favorite toy, when mowing the lawn every. single. time... when you know eventually you're going to just run it over and ruin their life... or you could move the toy...

Sadly, even just a few washes, destroys glass, fiberglass gelcote, and car paint. My 2009 Tahoe was so bad I paid out over $2200 to have the panels wet sanded to fix what they could. They didn't even do the roof, and after taking it three places, replacing the glass (sunroof) and all side glass was the only solution all three said was viable to fix the spots on the glass. (I decided to live with it).

My all glass shower door was 100% spotless when installed. Today, NOTHING will touch it. I even tried wet sanding the damn thing. Barkeeper's friend, water spot remover, vinegar, human blood, oven cleaner.... And yes, we tried to dry it every time we showered, but seriously? I have things to do... like wash my car...
The glass now is almost tinted look, tinted white. It's... not ideal... but water company wanted $6k to do a whole house RO system. and $6k is a lot of shower doors...

I'll try to find a pic of the Tahoe, but I sold it years ago.

With that massive expense, I swore I was never going to use that water again. Although I did try with my 2012 Wrangler... and it ended up with spots, even with the idea of quickly drying the vehicle... and there is not much surface area to a Wrangler...

So when I got my first Tesla, back in 2015, I ended up with a $300/yr car wash plan. (2 cars starting in 2018, $600).

and, I'm just tired of paying it, for something that causes me more stress and money.

As for water-less... it's neat but, Call me old fashioned, I like a garden hose. :)

Correct, anything holding DI water, that is metal will most likely not last forever. Luckily the pipe is PVC and PEX. So only the pump casing is metal. If it lasts 5 years, I'd be more than happy. 10 would be super. :)
 
You're old fashioned. But so am I in many ways.

I see vehicles like your water-spotted Tahoe regularly from people that live out in the country and have hard well water. I absolutely believe you in regards to the mineral buildup getting so bad that nothing will remove it (not even human blood!), or the cost being so high that it's better to just replace whatever it is.
 
I have a lot of experience with water quality ( had a company that maintained and kept saltwater reef tanks for over 20 yrs). I would bypass the DI, you will burn through DI cartridges which are not cheap and not only is DI water not needed for your application but IMO can be detrimental. DI water has no minerals so it will not have a steady PH level and will be acidic. IME a company called Spectrapure has the top filter replacements
 
The RO comes out around 3-5TDS and after DI it's zero TDS. But you suggest to bypass it? I've seen car wash systems that are only DI...? I don't want to wash the car with acid, but I would like to know more. Thanks.

Example: https://www.amazon.com/APEC-Water-Systems-Deionization-CWS-300/dp/B01LY0WXU4
IP agree with azjohn.
Also, just because you've seen it, doesn't mean it's working or is a good idea.
I had a DI system installed for my detail company; after 6 months I ripped it out and went back to city water because there was no return on investment. It didn't save time or prevent water spots. It just added to my overhead in both maintenance product cost, metal parts corrosion costs, and worker's time to maintain.
Using a rinseless solution like OCNR and/or drying immediately saved time and prevented water spots.

I encourage you to mix up a batch of OCNR using your hard well water, put some in a quart trigger sprayer bottle, squirt some on the fender of your car and let it dry completely. Then see how hard it is to wipe the resultant water spot off is. You will see that it wipes right off, leaving no permanent deposit like raw well water does. If you've freshly waxed/sealed or have a ceramic coating applied it will wipe off even easier.
 
Thank you for the info. I will do some more research! Do you think the 3-5TDS water is low enough to not leave spots? Is there any vehicle harm with DI? I just bought some PH test strips.
Those TDs numbers are one thing, but in my experience you truly have to just try it for yourself and see what happens. Those TDs numbers are theoretical and don't take into account anything that is picked up by the water downstream. Also remember that like azjohn hinted, since DI water is free of all minerals it attracts those minerals downstream from your metal fittings. Any minerals it picks contribute to your TDS number. How much? Not significantly but it doesn't take much to leave a spot on a dark colored car.
Is DI water harmful to your paint's finish? No, not any more than any other water left on the surface to evaporate is.
 
Thank you for the info. I will do some more research! Do you think the 3-5TDS water is low enough to not leave spots? Is there any vehicle harm with DI? I just bought some PH test strips.
3-5 is excellent. IMO not worth burning through DI cartridges. Anything less than 50 you will be ok. TDS of 135 I would guess your PH would be slightly acidic which I wouldn't worry about