Altenative to isopropyl alcohol

[G7PSK]

I am fortunate to have a contact who works at a hospital in the supply chain and I asked him once what they did with the out of date alcohol wipes that are used prior to a needle injection and he said they simply get discarded, I told him to keep an eye out for some and a few weeks later he turned up with a big box of them, I still have hundreds of them left and a constant supply if required.

I remember Dave mentioning once that he buys them from the supermarket and I have since seen them in boxes on the shelves but they are relatively expensive compared to IPA in a bottle, certainly worth a look otherwise another option would be to ask your local doctor to put some aside, these wipes are fine to use for most clean up applications but they can leave the odd fibre behind, no big deal considering how quick and convenient they are.

I knew someone who worked in the Cavendish laboratory, every time a fresh batch of bottle washing alcohol arrived he analysed it to check whether it was ethyl or methyl if it was pure ethyl he made gin from it, whole carboys of gin.

[David Hess]

I've used ethanol fireplace fuel, and while it's a good cleaner, the Bitrex (denatonium) denaturant makes everything bitter, from my fingers, to the outside of my spray bottles... even just grabbing them later spreads bitrex everywhere. (I don't know what the electrical properties of bitrex are, either.)

Separating the alcohol from the water is easy enough - any high school chemistry laboratory has the apparatus required, and any competent handyman could build it from commonly available hardware and domestic utensils.   However, safety when distilling it is more difficult - Ethanol vapour is dense and has a lower explosive limit in air of only 3.3% and a flash point of 14 deg C - and in most countries obtaining a licence to distill alcohol legally is even more difficult (and expensive), or totally impossible for a private individual.

I does not matter for removing flux but I have heard horror stories about store bought IPA and hardware store bought solvents being contaminated with things making them poor cleaners if you want something actually clean.  This is easy enough to test on an optical surface.  It really is a sad state of affairs that the only thing preventing use of the safest and most effective cleaners are politics.

Where it matters, I end up cleaning again using hot distilled water and a detergent like dish soap or TSP following by rinsing in hot distilled water and baking but I do not have any good solution for if the alcohol or solvent wash does not remove all of the flux leaving white deposits behind other than to start over from the beginning.

I bet alcohol in a vapor degreaser would be effective but it is also a fire hazard.  Offhand I do not know of any home builders with vapor degreasers.

[Cerebus]

I does not matter for removing flux but I have heard horror stories about store bought IPA and hardware store bought solvents being contaminated with things making them poor cleaners if you want something actually clean.  This is easy enough to test on an optical surface.  It really is a sad state of affairs that the only thing preventing use of the safest and most effective cleaners are politics.

This is where solvent grades matter. Depending on who you talk to, the grades from best to worst are: semiconductor (99.999+% pure, £60 a litre), spectroscopy (typical 1 ppm residue on evaporation, 99.9+% pure), analytical (99.8+% pure), reagent (99.5%), technical (99%) and commercial (95-8% pure).

The commercial grades are often the output of solvent recovery processing (fractional distillation) of mixed solvent wastes. So, if there's something deleterious to what you're doing with a boiling point close to the solvent you're using you may be in trouble. Of course, all you're going to find on the high street, fleabay and the other usual places are commercial grades.

[jpanhalt]

Separating the alcohol from the water is easy enough - any high school chemistry laboratory has the apparatus required, and any competent handyman could build it from commonly available hardware and domestic utensils.   However, safety when distilling it is more difficult - Ethanol vapour is dense and has a lower explosive limit in air of only 3.3% and a flash point of 14 deg C - and in most countries obtaining a licence to distill alcohol legally is even more difficult (and expensive), or totally impossible for a private individual.

Did you notice that the author mentioned 96% ethanol?  Although that composition is by itself is a bit odd, your suggestion for getting 100% ethanol from it by normal distillation is bizarre.

You need to read about azeotropes.  I hate to reference Wikipedia, but maybe you should start there: https://en.wikipedia.org/wiki/Azeotrope

Apropos my earlier comment in this thread,  you are more than three orders of magnitude off base.  BTW, there is a way to do it by distillation (i.e., get 99%+ of ethanol). Maybe you can clarify your statement by describing that method.

Ethanol is maybe a bit odd in that its solvent properties vary greatly from 95% to absolute (100%) with the other component being water.

John

[IanB]

Here in the USA you can obtain KleenStrip Green denatured alcohol from hardware stores, which consists mainly of ethanol, methanol and other organic solvents. It is good for cleaning and seems to leave no residue.

In the UK I have found the standard purple kind of methylated spirits to work very well for cleaning windows and mirrors without leaving any smears or residues.

[Bud]

Look for ethanol fuel at fireplace stores and fireplace sections in big box stores. In Canada we have Bio Fuel brand which is 95% ethanol

http://www.canadiantire.ca/en/pdp/bioflame-ethanol-3-78l-0643537p.html

Also go to woodworking stores and look for ethanol based lacquer thinners such as this one
http://www.leevalley.com/en/Wood/page.aspx?p=20107&cat=1,190,42942

I've used ethanol fireplace fuel, and while it's a good cleaner, the Bitrex (denatonium) denaturant makes everything bitter, from my fingers, to the outside of my spray bottles... even just grabbing them later spreads bitrex everywhere..

The Bio Flame one seems to only be ethanol/water or ethanol/propanol mixture.

[Ian.M]

@jpanhalt,
Tooki mentioned "non-denatured ethanol (i.e. 96% alcohol from the liquor store) costs $70/liter." and indicated a desire to be able to use  "40% vodka for $12/l," after removing the excess water.

I am well aware of the impossibility of separating the ethanol/water azeotrope by ordinary distillation at atmospheric pressure.   However with appropriate fractional distillation apparatus you can get to the aezeotropic composition in one step, meeting Tooki's requirement for 96% alcohol.

Once you have reasonably dry alcohol, (say 90+% if you want a decent yield), back in the first page of this thread I mentioned drying with calcium oxide and redistillation, which with a drier tube guarding the vent of the receiving flask can easily give you 99+% purity.   Also, vacuum fractional distillation of ethanol at less than 0.1 bar avoids the azeotrope problem (though at the cost of considerably more complex apparatus, especially if the pump cannot tolerate significant quantities of ethanol vapour or water vapour).

[nanofrog]

Here in the USA you can obtain KleenStrip Green denatured alcohol from hardware stores, which consists mainly of ethanol, methanol and other organic solvents. It is good for cleaning and seems to leave no residue.

According to the 11 July, 2014 revision of the MSDS for KleenStrip Green Denatured Alcohol, the composition is...

                                                                                                                               CAS#             Concentration
1. Ethyl alcohol {Ethanol}                                                                                          64-17-5          85.0 - 90.0 %
2. Methanol {Methyl alcohol; Carbinol; Wood alcohol}                                                  67-56-1          <=5.0 %
3. Methyl isobutyl ketone {Hexone; Isopropylacetone; MIBK; 4-Methyl-2-pentanone}     108-10-1        < 3.0 %



And as of the 13 April 2015 revision MSDS for KleenStrip Denatured Alcohol is...
                                                                                                                               CAS#             Concentration
1. Ethyl alcohol {Ethanol}                                                                                          64-17-5          30.0 - 50.0 %
2. Methanol {Methyl alcohol; Carbinol; Wood alcohol}                                                  67-56-1          40.0 - 60.0 %

[tooki]

This is where solvent grades matter. Depending on who you talk to, the grades from best to worst are: semiconductor (99.999+% pure, £60 a litre), spectroscopy (typical 1 ppm residue on evaporation, 99.9+% pure), analytical (99.8+% pure), reagent (99.5%), technical (99%) and commercial (95-8% pure).

My local pharmacy/chemist carries a few grades of IPA, and I've normally bought technical, but the pharmacy tech girl there actually didn't know what the grades meant and thus couldn't explain it to me. Thanks for this!

At $30/l for technical IPA, for flux removal I may as well buy actual commercial flux remover, whose blend of IPA and hexane works better, at $40/l. So for now, I have the $10/l denatured ethanol fuel with bitrex for general cleaning of things that won't be anywhere near food, the flux remover for removing flux, and technical IPA for other tasks.

For what it's worth, the ethanol fuel I get seems to be perfectly good for cleaning -- it leaves no visible residue even on multicoated lenses (both camera lenses and my eyeglasses, which have $500 Zeiss lenses with modern out-the-wazoo multicoatings). But I don't know the electrical properties of bitrex, which I suppose could be an issue for cleaning super high impedance things (like DMM boards).

I wish Switzerland allowed for ethanol to be denatured with other solvents, but as far as I've been able to tell, the only denaturant allowed here is Bitrex. 

(I know there's a mechanism for labs and stuff to procure un-denatured ethanol without paying alcohol excise tax, of course. I don't really care if it's denatured, I just want it without the cursed bitrex!)

[tooki]

P.S. When I say no residue on lenses, I need to qualify that with "as normally polished clean with a tissue". I have no idea what happens if just applied and allowed to dry without mechanically removing the excess.

P.P.S. The best way to clean eyeglasses is with warm water and dish liquid. Rinse with water only to remove debris, then wash with dish liquid to degrease, rinse, and then polish dry with a clean tissue. Doing this (and never, ever polishing your glasses with a t-shirt without first removing debris) will get you praise from your optician, who will say that your lenses are in better condition at 4 years than most people's at 1-2.

P.P.P.S. Does anyone know where to get Kimwipes or equivalent in Switzerland???

[nanofrog]

Anything useful available at local paint stores? And if so, is it reasonably priced?

I ask, as I get denatured alcohol, acetone, xylene, and MEK this way and not feel like I've been robbed at gunpoint.

[tooki]

Actually I really should do that. I've checked the paint department of the (relatively small, downtown) hardware stores, and they have acetone and various paint thinners, but not an actual paint store.

I also need to ask a friend who recently opened his own pharmacy. Since he actually studied pharmaceutical chemistry, he'll at least know what I am looking for!

[Ian.M]

Bitrex is Denatonium Benzoate, which is a quaternary ammonium salt.   As with any other ionic compound, you don't want it as a residue on a high impedance PCB. I have no data on whether or not its hygroscopic, but other residual contaminants could be and could thus mobilise the Denatonium and the Benzoate ions. Its  highly soluble in water so water washing + a final deionised/distilled water rinse followed by drying at an elevated temperature would remove it down to levels where it is not a significant contributor to surface leakage.

It is possible to strip it from alcohols - see http://www.forensicscience.pl/pfs/63_zuba3.pdf however methyl hypochlorite may be formed and is highly explosive, and other alcohol hypochlorites are also thermally unstable, + you would need to distill the product to reduce sodium, chloride and chlorate ion concentration to an acceptable level, so you are back to obviously illegal processes (though simply attempting to remove a denaturant is illegal in most jurisdictions).   I suppose you could live dangerously and try granular calcium hypochlorite, followed by calcium oxide, settling and filtration but don't blame me if the reaction or its residue burns down or blows up your workshop or traces get you arrested as a terrorist next time you pass through airport security

[ebastler]

I wish Switzerland allowed for ethanol to be denatured with other solvents, but as far as I've been able to tell, the only denaturant allowed here is Bitrex. 

(I know there's a mechanism for labs and stuff to procure un-denatured ethanol without paying alcohol excise tax, of course. I don't really care if it's denatured, I just want it without the cursed bitrex!)

I would think that the Bitrex is negligible, as far as residue is concerned? Current German requirements for denaturing seem to be: 1% iso-propanol, 1% methyl ethyl ketone, and 0.001% Bitrex; I assume the recipe will be quite similar across Europe. The Bitrex ("world's most bitter substance") is just to really make sure you don't want to drink the stuff... https://de.wikipedia.org/wiki/Verg%C3%A4llung - sorry, German only.

[Ian.M]

Countries with an illegal home made spirits problem are likely to use a much higher Bitrex concentration so enough carries over in a typical home still to maintain an effective concentration in the distillate.  e.g. Polish regulations call for rectified spirits to be denatured with 1g/l of Bitrex. (+crystal violet die) to make it exempt from excise tax. 

Concentration due to evaporation could increase the amount of residual Bitrex on the PCB surface by an order of magnitude

[BBBbbb]

P.P.P.S. Does anyone know where to get Kimwipes or equivalent in Switzerland???

Edmund Optics
(https://www.edmundoptics.com/lab-production/cleaning/lens-tissue-cloth/)
Thor labs
(https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=330)

Both have stocks in Europe and do delivery there.

Another option is to look for "lens tissues", a lot of brands (mostly cheap Chinese) on ebay, and they are mostly good for everyday cleaning when you don't want residues.
If you're looking for a quality brand you can try Tiffen (Kodak used to rebrand them back in the day).
If you need bigger wipes also a lot of the cleaning stuff you can find at the suppliers for "clean rooms", there are several in DE that might deliver to you.

[tooki]

I wish Switzerland allowed for ethanol to be denatured with other solvents, but as far as I've been able to tell, the only denaturant allowed here is Bitrex. 

(I know there's a mechanism for labs and stuff to procure un-denatured ethanol without paying alcohol excise tax, of course. I don't really care if it's denatured, I just want it without the cursed bitrex!)

I would think that the Bitrex is negligible, as far as residue is concerned? Current German requirements for denaturing seem to be: 1% iso-propanol, 1% methyl ethyl ketone, and 0.001% Bitrex; I assume the recipe will be quite similar across Europe. The Bitrex ("world's most bitter substance") is just to really make sure you don't want to drink the stuff... https://de.wikipedia.org/wiki/Verg%C3%A4llung - sorry, German only.

Have you worked with alcohol with Bitrex in it? I made the mistake of cleaning my eyeglasses with it once. For a week, if I touched my glasses and then put my fingers in my mouth (think like adjusting glasses while eating), it could taste that damned stuff.

I don't think it's a big problem for most electronics, the issue is the bitter residue it leaves on everything. Alcohol is a useful household solvent, but not when it coats everything in bitterness that gets everywhere. IPA is easy enough to get, but I wish I could get something less odorous -- ethanol is much better in that regard.

[tooki]

P.P.P.S. Does anyone know where to get Kimwipes or equivalent in Switzerland???

Edmund Optics
(https://www.edmundoptics.com/lab-production/cleaning/lens-tissue-cloth/)
Thor labs
(https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=330)

Both have stocks in Europe and do delivery there.

Another option is to look for "lens tissues", a lot of brands (mostly cheap Chinese) on ebay, and they are mostly good for everyday cleaning when you don't want residues.
If you're looking for a quality brand you can try Tiffen (Kodak used to rebrand them back in the day).
If you need bigger wipes also a lot of the cleaning stuff you can find at the suppliers for "clean rooms", there are several in DE that might deliver to you.

Thanks, but I was really looking for vendors in Switzerland, because ordering from abroad generally triggers enormous customs fees. (Also, lens tissue and kimwipes aren't the same thing.)

[Cerebus]

This is where solvent grades matter. Depending on who you talk to, the grades from best to worst are: semiconductor (99.999+% pure, £60 a litre), spectroscopy (typical 1 ppm residue on evaporation, 99.9+% pure), analytical (99.8+% pure), reagent (99.5%), technical (99%) and commercial (95-8% pure).

My local pharmacy/chemist carries a few grades of IPA, and I've normally bought technical, but the pharmacy tech girl there actually didn't know what the grades meant and thus couldn't explain it to me. Thanks for this!

As I say, it depends who you talk to. The terms are pretty loosely defined and will vary a lot from supplier to supplier. So always read the specification sheet and treat my summary with a pinch of salt.

[ebastler]

Have you worked with alcohol with Bitrex in it? I made the mistake of cleaning my eyeglasses with it once. For a week, if I touched my glasses and then put my fingers in my mouth (think like adjusting glasses while eating), it could taste that damned stuff.

I don't think it's a big problem for most electronics, the issue is the bitter residue it leaves on everything. Alcohol is a useful household solvent, but not when it coats everything in bitterness that gets everywhere. IPA is easy enough to get, but I wish I could get something less odorous -- ethanol is much better in that regard.

I try to avoid denatured ethanol, because its smell annoys me. Not sure which constituent is responsible for that -- I assume that other components besides those required to consider it properly denatured (and tax-free) are allowed, and are usually present as they make the stuff cheaper to produce. In those situations where I have used it, I don't recall any exposure to the bittering agent, but I don't doubt your experience. Being very bitter is Bitrex' claim to fame...

I don't mind the isoproanol smell, and use IPA quite often. I find its smell much less annoying and less persistent than petroleum or nitro paint thinner (whatever is in there), and less intense than acetone or MEK -- although those latter smells are not unpleasant, in moderation. A matter of personal preference, I guess. 

[MLXXXp]

I use 1-propanol because I was given a large bottle of it (99.5% pure). How does it differ, when used as a cleaner or for any other purpose, from 2-propanol (IPA)?

[Old Don]

190 proof moonshine can be had under the counter in many locations - just saying.   

[boffin]

What would be proper and easily available alternative to isopropyl alcohol to cleanup spots/excess of liquid flux after soldering?

isopropyl alcohol is not available in local electronic stores, pharmacy drugstores does non sell even 100% ethyl alcohol, while 70% ethyl alcohol does not help much.

I use a 50/50 combination of 99% IPO (from the local drug store) & my wife's nail polish remover (which is acetone based).

It's not enough acetone to really go after plastics, but it does a better job than the IPO by itself.

[Ian.M]

Depends on the soldermask.  Acetone has virtually no effect on fully cured epoxies.   However it is likely to remove inked component markings and attacks some plastics used for component bodies so its still risky.

[Old Don]

Different countries of the world have different names for isopropyl alcohol:  https://en.wikipedia.org/wiki/Isopropyl_alcohol