De-icer

[Blu3]

Hi there to all, I am trying to create a good de-icer as a small project. What I have done so far is:

 

60% Isopropyl alcohol

20% Methanol

20% Water

 

Do you guys think this is any good, I am aware that methanol is toxic but I had to add it to make it stronger. Also I am still not completely sure what kind of salt to add to it and whether if 1% should suffice?. I was going for table salt cheap solution or sodium nitrite and a bit of a corrosion inhibitor, but no the best. If you have any other suggestion regarding the salt or the formula I am all open to ideas. Thanks in advanced. Also dissolving the salt seems a bit tricky since it does not dissolve? any suggestions about this?

[Klaynos]

For any advice you'll probably need to give some details of application.

[Blu3]

@Klaynos Gladly but I assumed I provided all the necessary details, please tell me what more do you need and I will tell you right away.

[John Cuthber]

What are you trying to de-ice?

If it's plastic then we don't need to worry about corrosion, but the alcohols might attack it.

How cold do you need to go?

How much are you able to pay?

Are you worried about toxicity?

 

and so on.

[Klaynos]

Is it going to be released into the environment and where you are as lots of places have controls on that.

[Blu3]

Ok It is a de-icer for windshields, glasses and mirrors for vehicles. I have no limits to how much I can use the products. As for the winters it never goes lower than -14 but even this is very rare. But lets assume that temperature. I am also curious as to whether using only methanol for example 70% methanol and 30% water, as I have seen brands like prestone that use methanol for their de-icer, would that work well?. Thank you for replying and helping me out friend.

[DrP]

Hi,

 

This might be a stupid question, but I have to ask, why do you need the methanol at all? Wouldn't a mix of IPA and water, say 70/30 be good enough? It would have a freezing point of around -29C according to a chart I found on wiki. This would save any fuss about the toxicity of the methanol. If this is too high a C, then an 80% solution freezes at -37C from the same chart.

[John Cuthber]

For a given temperature methanol is likely to be quite a bit cheaper but more toxic.

Ethanol is somewhere between the two in terms of effectiveness, but it's expensive- though it's probably rather less toxic.

 

If you want something that evaporates readily without a residue, then the alcohols are fine, but if you want it not to boil too easily then something like glycol is better- but it's relatively expensive, not very effective (at a given %m/m) and also rather toxic.

 

There are a whole bunch of trade-offs that you need to consider.

Unless you know what the circumstances are, there's no way to know the "right" answer.

[DrP]

For the small difference in price I think using methanol is just a no no then - the price isn't that different (2 or 3 times the price? - negligible for screen cleaner). Again, some of the glycols have H&S issues. IPA is the way - slightly heavier than the smaller alcohols, works and is relatively safe.

In fact we make a window washer/de-icer at work... it is essentially just IPA and water with a little soap and sometimes some colour (blue or green) and some scent. I do not like the scents though... it comes in Mountain Pine or Russian Leather.... the Russian Leather smells more like Russian Ballsack in it's concentrate. :-/