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Making Your Own Windshield Washer Fluid

With 3 cars, we have to keep 3 windshield washer reservoirs filled during the winter months. I used to see a gallon of fluid for only 99 cents, but now I can’t seem to find it anywhere for under $1.50. Therefore, I made it my mission to find a recipe for my own washer fluid that is still safe to use in my vehicle. I don’t want something that will corrode or deteriorate the fluid lines or spray nozzles, so I’m careful about the acidic nature of some recipes.

Note: the reason you have to use a “special solution” rather than just water is because the solution has chemicals that prevent the fluid from freezing in the lines. You can’t just put regular water in there, at least in the cold months.

When I Googled for a recipe, I found that eHow.com has a 5-step process. You basically water down regular window cleaner. However, it doesn’t calculate the costs of using window cleaner vs just buying the auto solution.

Many of the other results were just reposts of the eHow recipe, so if any of you make your own fluid, please comment with your recipe, your results and your cost breakdown!

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Clever Dude

48 Comments

  • Allison, a hair dryer will thaw things out if you don’t mind spending some time out doors or in your garage under the hood with a hair dryer. perhaps a small space heater?either will thaw the lines no problem, the trouble spot is going to be the plastic tank with the
    large chunk of frozen water in there. You may want to use some real windshield washer fluid to pour in to help delute the water with something that won’t freeze as you thaw it.
    once thawed, you need to get all the water out, the best way I suppose
    would be to spray it out through the washer. hopefully the little pumps aren’t damaged. Careful with electric equipment in winter conditions. Be careful not to expose the end of the ext cord to water or snow. Getting shocked sucks.

  • I live in Canada , Ontario and we are facing around 6 month brudal winter with mostlikly minus temperatures the 6 month long.
    I have 2 cars and go through 1 gallon WWF each car each week. Not cheap ? Figure this. average costs / gallon around 3 CAD$, times two cars times 4 weeks, times 6 month. thats $ 144 during a winter season… blown in the wind … just like that…. thats $72 each car. i am not sure about how many cars are here on the road every day but just asume 1.000.000 cars thats whopping $72.000.000 a season blown in the wind… and there is no other affordable, environmently friendly solution to prefent WWF from freezing ??
    Greez from Ottawa Canada

  • I work for a Chemical Distributor in PA, and we make this stuff. The “commercial” version uses Methyl Alcohol (methanol) instead of Alcohol. It is basically Methanol, water and a pinch of dye and a surfactant which takes away the surface tension of the water so it does not just bead up on your windshield.
    Commercially, methanol can be bought by the tank truck for about 70 cents per gallon. Considering that a washer mix that would give minus40C protection is a 50/50 methanol/water mix, the cost of the stuff in the jug, not counting labor, is roughly 35 cents. Add the cost of the jug, and you have some idea of the markup on this stuff.

  • If you want to use isopropyl alcohol, DO NOT USE rubbing alcohol. Rubbing alcohol is designed to rub on peoples skin and also contains oil to prevent the skin from drying out. Isopropyl comes in either 99% or the standard dilution of 70%/30%.

  • Well the best and cheapest anti fog coating contains alcohol(rubbing). You know two of the best window cleaners used by themselves seperately are white vinegar and rubbing alcohol.

    If you smell the windshield washer , you will smell either alcohol or you smell ammonia,

    Ammonia traditionally has been used for many many years as an industry standard in the janitorial cleaning trade, diluted of course with water to clean windows. Alcohol does not freeze at 32 degrees, this is why windshield wash contains it. The more ratio of alcohol the less it will freeze in winter as the temperature drops lower and lower.

    Missing though is the petroleum based chemical that keeps the window and mirrors from fogging. The oil based solvent will bond with the alcohol to hold up under moisture accummulation and keep windows and mirrors from fogging.

  • Wow, I can’t believe anybody hasn’t mentioned how toxic and bad for the environment methanol is! There are some green cleaners out there at Walmart and Home Depot and other chain stores that are methanol free. Check ’em out.

  • For 50 years successfully living in Maine, New Hampshire, Vermont, Green Bay Wisc, PA, Connecticut, Illinois, Iowa: one gallon water, alcohol (any kind) 1/3 bottle, one squirt of dish detergent. Never froze up, never a mess, no streaking, problem. Changing Times Magazine was the resource 50 years ago. Thanks for the interesting reading.

  • Hah, I can’t top Ryan’s ingenious use of rum, but I suspect that if you want to follow Jay’s guidelines for an alcohol/water mix, you could use a drop or two of Photo-Flo for the surfactant . That is, if you still have that old box of photo chemicals left over from your darkroom. Super concentrated, a little dab will do ‘ya. Don’t figure I’m going to save any money, I just don’t feel like driving to the store in the middle of a snowstorm.

  • I can’t believe this topic is still going strong! Yesterday I ended up buying some Rain-X fluid, it was orange and about $4 a gallon I think.

    At the auto parts store, the blue stuff was $2, the Rain-X (orange) was $4 and there was the clearish Yellow Prestone stuff for like $6 a gallon.

    I went with the orange and I’m pretty happy with it.

    I fix cell phones in the Washington DC area and I consider myself a pretty “clever dude” but I think in this case it’s worth the $4 to not bother with the hassle!

  • I am blown away that there are people as cheep as me out there. I don’t even consider myself cheep but when I pour 4 bucks in a tank and then spray it out on the ground it urks me. It’s like going to the car wash on a slushy day. I just made up two different concoctions. One is 1 gal water with 2 cups isopropyl and a 1/2 cup concentrated window fluid from home depot. The other only has one cup of isopropyl in it. Got about a 1$ in one gal. I set them outside for the night see if they freeze. I will update you all on my findings..

  • Two cup of isopropyl was not enough, still froze in this artic tundra on northern Michigan. I just gave in and spent the 2.50. Maybe I’ll buy it buy the case in the spring when it’s cheep. Then I have to think about the intrest on that money being tied up all summer……… Il get back to you on that… Damn those dirty windows.

  • I have tried using some home made washer myself, but it did not work well. So, I don;t think spending £1.99 is a lot for something that will last the whole winter months.

  • I had to literally LOL at some of these comments. I live in Fairbanks, ALASKA where temps get to -40 and coldER! We plug in out vehicles just so they’ll start. If I could get a gallon of WWF for a buck fifty I’d be elated. I just came her looking for the balance of make-your-own stuff (for summer use) simply because I keep forgetting to buy some and figured I’d get it done right now. Instead I found humor =)) Thanks all!

    I opt for the store brand WWF w/ antifreeze in the winter time – it still freezes eventually; I use Bug Off in the summer time usually.

  • Here is a link to a website that lists freeze points etc for alcohols and water mixtures – none will hold up to 0 freeze point unless at least 20% to 25% alcohol. Dish washer rinse agent (super pure detergent) is good for keeping the water from beading up – that is what it is designed to do – 1 teaspoon max per gallon should be enough. The alcohol provides wetting action but not much cleaning.

    http://www.engineeringtoolbox.com/ethanol-water-d_989.html

  • Use “Jet Dry” as your surfactant. Thats the stuff you add to your dishwasher and the same surfactant that comes down on your car as the final spray at the carwash. I use one capfull in a 32 oz spray bottle for a great shine on my cars and cycles. . . Just sray it on and rinse it lightly off. One “Jet Dry” capfull in a gallon of homemade windshield solution would be plenty. . . . . . .I tried to get menthanol at Home Depot but they didn’t have any. ..” No I’m not trying to make methamphimine.”

  • Here is the formula to ascertain a certain freezing point change as a function of the properties of the solute and the solution.

    ΔTF = KF · b · i
    ΔTF, the freezing point depression, is defined as TF (pure solvent) – TF (solution).
    KF, the cryoscopic constant, which is dependent on the properties of the solvent, not the solute. Note: When conducting experiments, a higher KF value makes it easier to observe larger drops in the freezing point. For water, KF = 1.853 K·kg/mol.[4]
    b is the molality (mol solute per kg of solvent)
    i is the van ‘t Hoff factor (number of ion particles per individual molecule of solute, e.g. i = 2 for NaCl, 3 for BaCl2).

    Here is the formula to ascertain a certain freezing point change as a function of the properties of the solute and the solution.

    No , I still haven’t WITH 100% CERTAINTY produced a viable ( safe for the car/ less $ than anywhere else ) mixture.

    Cmon Nerds !

  • Living in southern California I use the DIY method in all 5 cars with no problem over the years. 1 gal. water, 1 T dish detergent, 1/2 cup ammonia and 4 drops of blue color for identification. Costs about a dime per gallon.

  • Thanks, Lewis! I kept reading for a recipe for warmer climate and you had one that is cheap and effective!! It is also similar to several other posts I’ve found, so that is good enough for me!
    Ten cents for a gallon! Our family has six cars so that is a nice simple savings.

  • My first two cars had broken windshield washers so i was accustomed to keeping a spray bottle of rain x and using that along with leftover drive thru napkins. Id spend about 3.50 for the bottle that lasted a year. Now that i have a car with windshield washer, i can’t believe how much more expensive and wasteful it is to use washer fluid. It wastes alot of water and the cost is MANY times more than just getting your fat toosh out of the car and wiping for 5 seconds . so now i have a spray bottle of rain x and i will also buy a spray bottle of deicer and a scrape thingie. I can afford it but i seeno point in wasting more money to be lazy. Btw ove discussed this with a few low income people (i literally talk to anybody 🙂 and they said they do what i do and just hand wipe it. they knew all along its the better option and its even cheaper than making your own fluid.

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