Comments on: windshield washer fluid

Question: windshield washer fluid

randomstriker — Sat, 07 Oct 2006 00:23:59 -0800

Windshield washer fluid vs. soap/detergent + water -- what's the difference?

Can I replace one with the other? Aside from the fact that it might be too sudsy...what problems might it cause?

By: knave

knave — Sat, 07 Oct 2006 00:34:04 -0800

It'll probably freeze in cold weather.

By: cosmicbandito

cosmicbandito — Sat, 07 Oct 2006 00:36:38 -0800

washer fluid is alcohol based. it dries quickly. and it's like $1 a bottle. soap and water will smear the window and the wiper blades will not be able to squeegee the soap film off the window.

By: empyrean

empyrean — Sat, 07 Oct 2006 00:37:04 -0800

Add some alcohol to that recipe to avoid freezing.

Googling reveals this recipe:

Ingredients:

* 3 cups rubbing alcohol
* 10 cups water
* 1 Tablespoon of liquid detergent

Makes one gallon.

Optional: You can add some blue food coloring if you like!

By: RichardP

RichardP — Sat, 07 Oct 2006 01:16:37 -0800

Commercial windshield washer fluids are typically 30-50% methanol, water, and perhaps a little detergent. Sometimes they contain a wetting agent that helps to minimize mineral deposits. If you choose to make your own, you might consider substituting distilled water for the water in your homemade recipe if your local water has a high mineral content. If you want to get your own methanol, a fairly easy way is buying the yellow bottle HEET brand gas line antifreeze - it's about 99% methanol. You can find it in auto parts stores.

By: randomstriker

randomstriker — Sat, 07 Oct 2006 01:36:56 -0800

soap and water will smear the window and the wiper blades will not be able to squeegee the soap film off the window

Then why can you squeegee it off with a squeegee?

So the alcohol is just to prevent freezing...unnecessary since I live in a locale where it rarely dips below freezing?

By: PercussivePaul

PercussivePaul — Sat, 07 Oct 2006 02:17:36 -0800

While in California I ran out of washer fluid and got it refilled at a local gas station. They mixed up some liquid in a bucket with water and some special soap. It was real cheap and kept my windshield nice and clean. Then I drove back home to Ontario, and first snowstorm - frozen solid!

If you live in a warm climate you're fine. Just don't go driving up in the mountains in winter.

By: Thorzdad

Thorzdad — Sat, 07 Oct 2006 05:09:16 -0800

Then why can you squeegee it off with a squeegee?
Because, with a handheld squeegee, you are exerting far more force on the blade (in order to remove the soapy film) than is ever exerted by your wiper blades.

By: Mitheral

Mitheral — Sat, 07 Oct 2006 07:52:33 -0800

Be careful that your choice of detergent doesn't remove wax. Many laundry and dishwashing formulations are designed to.

By: mendel

mendel — Sat, 07 Oct 2006 08:30:50 -0800

So the alcohol is just to prevent freezing...unnecessary since I live in a locale where it rarely dips below freezing?

No, it'd be unnecessary in a locale where it never dips below freezing. Remember that the 60mph wind that your wet windshield is exposed to on the highway will make things a bit colder for your washer fluid too.

By: Kwantsar

Kwantsar — Sat, 07 Oct 2006 08:52:45 -0800

Remember that the 60mph wind that your wet windshield is exposed to on the highway will make things a bit colder for your washer fluid too.

Not exactly. It will bring the temperature down faster, but it won't cool the fluid colder than ambient.

By: aubilenon

aubilenon — Sat, 07 Oct 2006 13:03:39 -0800

Kwantsar: yes it will! Evaporative cooling is how come humans are only 98.6 degrees even if the air is 102 degrees.

By: Kwantsar

Kwantsar — Sat, 07 Oct 2006 13:24:14 -0800

Great. Now you can show me the sweat glands on the washer fluid reservoir.

By: Kwantsar

Kwantsar — Sat, 07 Oct 2006 13:29:52 -0800

Or you could take the NOAA's word for it.

By: jamjam

jamjam — Sat, 07 Oct 2006 14:08:18 -0800

I wouldn't mess with methanol. The Merck index says as little as 30ml (~1oz) has been fatal, that it can be absorbed through the skin or by breathing vapors (your car's air intake may be at the base of your windshield-- mine is), and that chronic exposure causes visual impairment.

By: Opposite George

Opposite George — Sat, 07 Oct 2006 14:16:23 -0800

Great. Now you can show me the sweat glands on the washer fluid reservoir.

I think what mendel is suggesting is that the fluid will freeze on the windshield, which is arguably more dangerous than having it freeze in the reservoir.

By: mendel

mendel — Sat, 07 Oct 2006 19:39:00 -0800

Yeah, that's what I was suggesting. That happens about once a year to me, when it gets cold and I still have the "get the bugs off" summer fluid in instead of the "don't turn the windshield opaque" winter fluid in. It's even better when you're using the fluid to clear the window because of freezing rain and you end up just adding more freezing rain.