At more than one site, more than one venue, I've read or even seen videos recommending you occasionally clean your wiper blade off with Isopropyl Alcohol.

It's a pretty common recommendation.

I don't do this.
This is my logic. Alcohol dries things out. Seems to me the LAST thing I want to do is dry my wiper blades out prematurely.
Therefore, I wipe my blades down with water....and that's about it.

So just wondering, am I wrong in this thinking?

 

I wouldn't use alcohol either. I usually use window cleaner because it's handy and cuts the oily grime pretty well. In any case, wiper blades live a tough life and their lives seem limited regardless of how well I treat them.

 

I save the alcohol for consumption (but, only if it's properly aged, of course). <HIC>



I wipe the blades lightly with the same netting-covered sponge that I clean the window glass with. The netting removes grit from the glass and the wiper blade.

 

I don't think alcohol harms rubber. There is no water in the rubber for the alcohol to remove, and thereby dry out the rubber. Windshield wiper fluid is a mixture of water and alcohol. Not sure how much alcohol but it shouldn't be too hard to find out. The alcohol both cleans the window, and prevents the fluid from freezing. It is always labeled as to how low of a temperature it can go to without freezing. The lower the tempearture, the larger the percentage of alcohol.

 

Hmm..
You are of course absolutely correct about most windshield fluids having a degree or percentage of alcohol in them to make them less prone to freezing.

But I still think it's a bad idea to directly apply isopropyl acohol to your blade.
Rubber does dry out over time, and I don't see how direct applications of alcohol wouldn't expedite that process.

Basically you just want to keep your blade clean. Why not just soapy water or car wash soap? Rinse the blades well?

 

Rubber does dry out over time but I don't think it is caused by water leaving the rubber. I don't see how direct application of alcohol would expedite or accelerate the process.

I suspect it is a chemical reaction that occurs slowly as the rubber ages, and is accelerated by sunlight.

 

Windshield wiper rubber strips are made out of synthetic rubber which is a petroleum product. During production it contained petroleum solvents and petroleum oils but the solvents are mostly gone from the finished product. The finished product is already "dried out." Some oils remain. These help keep it flexible. There is no appreciable amount of water in the rubber. The elastomer, deteriorates with age, become less elastic, that is, it gets relatively brittle as opposed to remaining relatively elastic. It can also get mushy and sticky and surfaces and edges may be susceptible to being wiped away. It simply undergoes chemical changes as it ages and does so fairly rapidly. Chemicals are added to slow down the process somewhat but they are not able to arrest the process. Ultravioltet from sunlight and ozone from the air speed up the process. Oxygen in the air also contributes to the process but ozone, a form of oxygen, speeds it up even more. Alcohol, like brake fluid, is hydroscopic, that is, it attracts moisture from the air and the moisture dissolves in the alcohol. If alcohol could be added to windshield wiper rubbers it would attract water. But it cannot be added. Cleaning the rubbers with petroleum solvents or oils will dissolve the rubber. The rubber dissolves in these things. The outer layer will be changed as a result, damaged. The reason alcohol is recommended is because the rubber does not dissolve in alcohol. There is little or no interaction between the 2 substances. Some inserts are made out of silicone rather than the more frequent butyl rubber, I think it is. The same cautions apply to silicone wiper inserts. However silicone deteriorates more slowly than the butyl rubber that I think ordinary inserts are made out of, and silicone is equally as flexible and works as well to wipe windows, so one might want to spend extra money to get silicone inserts.

 

Educational write up. Thanks