Wednesday, February 08, 2006
Homemade windshield washer fluid - the recipe!
The versions with "bug remover" contain a dash of 2-Butoxyethanol. That's going to be a bit harder to track down, but if you're trying to save money by making your own windshield washer fluid, it's something you can leave out anyway.
The whole Household Products Database is useful if you want to try making your own copy of a commercial product. For example, many octane boosters are mostly JP5 jet fuel. And STP Fuel system cleaner is mostly napthalene in kerosene.
Labels: Automotive chemicals
in Russia, we use ethanol or isopropyl instead of toxic methanol. We love winter ))). Just add detergent \ PAV to your solution - and no difference with commercial products. G.Luck!
It evaporates VERY quickly and is highly flammable with an effective octane rating of 120.
What to do the commercial WWF Mfr's use? Some sort of Glycol, I'd guess. If that's true, you could probably find a source of Propylene Glycol (food grade; non-poisenous) and fine-tune your recipe to local conditions.
Rubbing alcohol doesn't cut it. In desperation, I tried it one day when temps were in the low teens (F). The streets were coated with liquid Mag-Chloride, I was out of WWF, the convenience store was out, but had some rubbing alcohol (a pint, or half-litre, I think), which I mixed on the spot in my just-emptied WWF container. It froze to my windshield and stunk to high heaven.
2. Due to its volatility, the environmental persistence is low and there are zero credible medical reports of anyone getting sick from passive exposure to methanol in household water.
3. Methanol is not a controlled substance by DEA law, by watch list, or even Title 27 of the CFR. In fact, it is a common denaturant in ethanol (see 27CFR part 21). Methanol is "readily available without a precription" at hobby stores as a fuel for R/C vehicles, as is indicated in previous posts.
3. Glycols such as ethylene glycol do not work as windshield washer fluids due to their low vapor pressure. Think of spreading Karo syrup on your windshield when it is cold outside.
4. Methanol in windshield washer fluid does not flash. I am unaware of a car fire ever being started by ignition of windshield washer fluid.
5. Accidental sip ingestions of methanol do not result in systemic toxicity. Generally speaking, the only people who get sick from methanol exposure are those who drink it. Those huffing carburetor fluid frequently get very high blood methanol levels, but they rarely develop systemic toxicity such as metabolic acidosis without having ingested some of it.
6. Propylene glycol is not volatile enough to use as a windshield washer fluid (see comment #3 above). Plus ingestion or injection of propylene glycol (in sufficient dose) can be posionous - propylene glycol is metabolized to lactate so the patient develops a metabolic acidosis. We see this sometimes in people on long term high dose lorazepam infusions in the ICU.
7. I just bought a gallon of the blue stuff for $1.88 at the Safeway gas pumps. How much of this stuff would you have to use to financially justify making your own? Does it really save that much money? If so, might it be time to re-evaluate where you are driving? Driving on the actual road might help.
My reservoir holds about half a gallon, so adding a bottle of heet would boost the percentage by 15-20% depending on the current amount in it.
One Gallon Container
1 cup epson salt
1/2 teaspoon dish detergent
1/2 cup "dry gas"
and just for added protection
1/4 cup enviro safe anti-freez
If you follow these simple measurements and trust me when I tell you ..... please mix the dry gas with water and salt then add dish detergent then finaly your anti-freez . It is a no brainer and you will find it works great.
In Ohio, we salt the roads. Once the snow season starts, any moisture on the road contains salt. When it gets thrown on your windshield, it dries to a haze.
Washer fluid is also used as a deicer - it can take quite a bit to get the windshield visible enough to drive, and some days it requires a few squirts every minute or so to maintain visibility.
What all that means is you can easily go through more than a gallon per week just commuting back and forth to work.
Beyond just saving money, for some reason the stores all tend to run out at least once every season for a few days to a week - usually when an unexpectedly bad storm hits, so the ability to make one's own would be a real plus.
For added protection, one can add ethylene glycol or propylene glycol. Both are also used as antifreeze in engine coolants. It is commonly known that these coolants, as opposed to methanol, are less effective undiluted than in a solution with water. The eutectic solution for both of these glycols is around 63%. Their eutectic temperatures are very low, -50 to -70 C, but in practice it is not feasible to guarantee protection to these temperatures because the freezing point increases steeply at either side of the eutectic concentration, so the properties of the fluid are difficult to control (the reason we never use more than a 50/50 mix for engine cooling seems to be the price paid in terms of heat transfer at operating temperature).
Propylene glycol is more expensive than ethylene glycol and more viscous at low temperatures, but has less of an impact on the environment.
Thus, one could use a 30-40% methanol mixture with some ethylene or propylene glycol thrown in. However, without additional information it is impossible to predict the freezing point of a given water/methanol/ethylene glycol mixture. This is exactly what for instance the PEAK -30 brand does. The propylene glycol content is less than 5%. Why it is so low is anybody's guess, but it could be due to viscosity problems at low temperatures or environmental concerns. Speaking of environmental rules, methanol also seems to be regulated by VOC (volatile organic compound) rules in California and elsewhere.
(where winter temps occassionally reach -40) we used to mix methyl hydrate and water at about 30% methyl to 70% water for windshield washer fluid in the winter. Methyl hydrate is readily available at hardware and paint supply stores as one of its uses is to thin shellac.
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