Homemade windshield wiper solution/ isopropyl(?)

I’ve found several recipes for homemade windshield wiper solution. One question that no recipe seems to address is how damaging is isopropyl alcohol (usu “add 3 cups per gallon”) to the hoses that carry it to the windshield. Does anyone have a REAL clue as to the effect? I just dont want to end up facing a costly repair for cheap economy. I realize that this is a winter and not a summer issue. tnx.

Why bother? Go purchase a gallon bottle of washer fluid for a buck.


I agree. I used store-bought fluid for years in my Toyota Pick-up and never had a problem. I had that truck for 15 years. The most I paid was $1.50/ gal. A few times, got it for free with certain purchases. What’s the big deal?

Proceed with your plans for the homemade brew. I understand where you’re coming from; this is not a matter of economics.

Isopropyl alcohol is totally harmless to the hoses and all other components. Commercial windshield fluid uses methyl alcohol which is potentially more corrosive than isopropyl, but the hoses have no trouble dealing with commercial washer fluid. And summer or winter has no bearing on the case.

And methyl alcohol is not something we should be breathing much. Methyl alcohol is pretty poisinous, in sufficient quantity will make you go blind (i.e. if you drink it.


IPA is only a problem for vinyl, and your hoses are not vinyl if the are OEM.

Methanol is a lot more polar than propanol. I don’t know how you can tell if it is safe unless you test all of the parts that will contact it in your particular car. There is no way this will work out less expensive unless you get the propanol for free.

i used bottles of isopropyl alcohol on the windshields of a boat i used to work on. it took two sets of wiper blades to realize that the store bought stuff was (in the end) cheaper to use, and more effective.

the wiper blades MAY not have been eaten up by the alcohol, but after i started using rainx again, the blades stayed for about two years. SO… i am a firm believer and convert to rainx.

Which is worse for the paint- isopropyl or methyl? It would seem that would be a major concern.

All washer fluid is bad for rubber. Summer fluid is probably good but you don’t want it in Winter. You don’t want it to be flammable. You won’t have costly repairs to the washer system unless you have to drive a long way to the Rolls dealer.

my mother used vinager in water to clean windows the best windows I ever seen. and if you stop by for dinner you will have the oil and vinager for the salad.

I doubt that either is bad for the paint, but IPA is less aggressive than methanol.

so are you saying windshield washer fluid is bad for the rubber wiper blades – and more so in the winter? What do you think of the suggestion made a couple below yours re: using vinegar and water for windows? Just wondering if I should switch to something new. Also, the toxicity of the window washer fluid – i never thought about that, and now another thing to consider.

Don’t panic, ritamd. In particular, don’t believe the tale that washer fluid is bad for rubber. If it were, 100 million drivers would have figured it out by now, don’t you think? Same goes for toxicity. You’d be in trouble if you swigged a pint or two, but just catching a few drops of overspray in the face? Refreshing! Continue using the commercial blue stuff. It is safe and effective.

thanks everyone who replied. I agree for a $1.50 there is far less worry with store bought. But this is more than just a matter of cheap economics or curiosity. I mean what do you do if the store(s) is closed and you are out (because your wife used up an entire gallon of the store bought stuff) and you NEED some NOW? I think there are two answers: Dont run out and buy two gallons. g.