Altenative to isopropyl alcohol  - Page 1
Forum section: electronics / beginners

author: sasa
author_rank: Regular Contributor
timestamp: August 23, 2017, 12:15:50 pm
content: 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.One left possible solution I'm still aware of is acetone, but that is not really a solution as it can dissolve many type of plastic (IC's, TO92 and similar plastic packages).I would not be able to order any chemical out of country as it is usually forbidden to transport any hazardous and flammable chemicals for individuals.

author: ironmonkey
author_rank: Contributor
timestamp: August 23, 2017, 12:24:32 pm
content: Hello Sasa. Isobutyl alcohol is another good choice and in a good chemical supply store you can get it.

author: plazma
author_rank: Frequent Contributor
timestamp: August 23, 2017, 12:27:50 pm
content: Where do you live? In Finland you can buy IPA as anti-freeze for air brakes or diesel engines.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 23, 2017, 12:41:01 pm
content: The stuff we call Methylated Spirits in Oz works quite well instead of isoprol alcohol.A lot of people fuss about it leaving a "white deposit", but if you clean it off with Kimwipes or similar,(Even ordinary tissues or toilet paper), the board comes up OK.If I was doing it for an employer who supplied the isoprol alcohol, I would use, & have used, that, but for my own stuff, "Metho" does the job.I've seen "white deposits" with isoprol, too, -----I think it is just a tiny amount of flux residues still there.

author: Ash
author_rank: Regular Contributor
timestamp: August 23, 2017, 01:07:54 pm
content: @sasa, not sure what country you're in but perhaps you need to search for other chemical suppliers, "consumer" level stuff is sometimes not very useful.Industrial processes like painting use solvents like this. Is there a car body or spray painting shop near you? they may be able to help or suggest a supplier.. They may not use isopropyl but they probably have a good supplier who will stock it.Just to clarify what @vk6zgo mentioned. Metho (or Methylated Spirits) is a Ethanol (also called Ethyl Alcohol, or booze) diluted with water. I don't remember the normal percentage, but 70% seems to ring a bell.. It also contains a "denaturing" agent - a really bitter substance that can't be distilled out so that it isn't drinkable and therefore the government duties are avoided.It is also possible to purchase "industrial pure alcohol" (IPA) which is basically undiluted Ethanol and the denaturing agent. I actually purchased this for making violin varnish and shellac, but that is a whole other hobby..I normally reach for the Isopropyl or the IPA, but I've also used Acetone on some things.Ash.

author: wraper
author_rank: Unknown
timestamp: August 23, 2017, 01:33:04 pm
content: If you live in EU, you can easily order huge amounts of IPA or specialized PCB cleaner from TME (EUR 7 delivery).

author: TomS_
author_rank: Frequent Contributor
timestamp: August 23, 2017, 01:40:42 pm
content: In the UK, I bought a bottle of isopropyl alcohol from Amazon.

author: drussell
author_rank: Super Contributor
timestamp: August 23, 2017, 01:41:46 pm
content: Quote from: sasa on August 23, 2017, 12:15:50 pmIt would be very helpful when answering a question like this if we knew what country you were in.00 isn't much help.

author: wraper
author_rank: Unknown
timestamp: August 23, 2017, 01:44:14 pm
content: Quote from: Ash on August 23, 2017, 01:07:54 pmI'm not sure if you are calling things with right words. Isopropyl alcohol and IPA is one and the same. I never heard about "industrial pure alcohol" as a name for denaturated alcohol. Denaturated alcohol is anything but pure. When it dries out, usually it will leave a thin layer of a crap it was denaturated with.

author: Ian.M
author_rank: Super Contributor
timestamp: August 23, 2017, 02:23:46 pm
content: Alcohols can be dried with anhydrous calcium oxide ('quicklime') which can be produced by heating natural chalk or white limestone to red heat and holding at temperature for a minimum of five minutes to drive off the carbon dioxide.Caution: quicklime is extremely caustic and its reaction with water is very exothermic. Research the hazards and use proper PPE!Start with the highest concentration clear alcohol without additives you can legally buy. Add the cooled quicklime SLOWLY to the alcohol, stirring continuously, and waiting (while still stirring) if the temperature rises excessively, till you are certain there is an excess over that required to react with the water content then agitate thoroughly at intervals for an hour or so. Ideally you'd distill the alcohol off the alcohol/quicklime/slaked lime mixture, but as calcium oxide and calcium hydroxide are nearly totally insoluble in alcohol, you could get away with filtration, settling and decanting.Methylated spirits does not normally contain more than 10% water as that degrades its performance as a stove fuel and reduces its utility as a cleaning solvent. However it is usually denatured with denatonium benzoate and a dye, which are generally undesirable on your circuit boards. It can still be used (to save on the 'good stuff') as a first stage flux removal solvent if you blot it up rather than letting it dry, and rinse with a small quantity of higher purity alcohol to remove as much as possible of the denaturants from the PCB surface. If you can obtain undied alcohol stove fuel it is likely to be preferable to methylated spirits for PCB cleaning as the denaturants tend to be volatile organics so they wont clog the burner wick. Whatever you get, test it by evaporating a small quantity to dryness in a watch glass or highly polished metal spoon to check for non-volatile residue.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 23, 2017, 02:54:34 pm
content: Denatured alcohol (the denaturant varies from country to country, including methanol (methylated or meths), bitterants, dyes and so on. It's as effective as IPA on flux.Acetone attacks very few things. Plastics are wholly unaffected. Semiconductors are made of epoxy, and other parts (like capacitors) are made in polymer boxes that aren't harmed.Some printing may be damaged: check the datasheet if you suspect a component is not solvent washable. Capacitors are a common victim here. (This goes for alcohols as well as ketones.)MEK also, which is a little more aggressive still towards some hydrocarbons, but mostly leaves components alone.Chlorinated solvents are also nice, if you happen to have them: 1,1,1TCE and trichloroethylene are frowned upon these days, but also very effective.DO NOT USE methylene chloride, a key ingredient in paint stripper. It swells epoxy!Hydrocarbon solvents, like toluene and xylene, cyclohexane, petroleum ether (ligroin) and so on, aren't very effective, and may damage some plastics.Tim

author: wraper
author_rank: Unknown
timestamp: August 23, 2017, 03:11:33 pm
content: Quote from: T3sl4co1l on August 23, 2017, 02:54:34 pmBut it usually leaves residue even if it's not noticeable. I stumbled that my hands became covered with bitter taste crap which hard to wash away after touching dry boards which were washed by denatured alcohol.

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: August 23, 2017, 03:27:43 pm
content: Acetone IS methyl ethyl ketone (MEK) and it attacks many case plastics so must be used with care. A source of small quantities is nail varnish remover.Isoproyl alcohol is safe on most components except soft rubber items, which it causes to swell long after its application. Never get IPA onto vintage tape mechanisms for this reason. It used to be used for video head cleaning, and the trap for young players was to clean the pinch roller with it as well. A few weeks later the machine would come in with a report of 'chewing tapes' and on inspection the pinch roller would be completely barrel-shaped.Methylated spirit is safe on most items except some clear plastic windows, which it may make cloudy. However, it is safe on rubber.Dihydrogen monoxide is, surprisingly, used in industry to clean PCBs. Main thing is to dry any populated board effectively and quickly after cleaning because of its corrosive properties on metal. Unheated air from a reasonably strong fan is better than heat. You need to assess whether there are any items likely to act as traps for it though, like enclosed but unsealed switches which might be hard to dry out. Probably best avoided on BGA chips too, for obvious reasons.

author: free_electron
author_rank: Super Contributor
timestamp: August 23, 2017, 03:33:32 pm
content: rubbing alcohol. get the 90% or 70% if you can;t find other one. and don't buy the aloe vera infused one.rubbing alcohol is IPA

author: Monkeh
author_rank: Super Contributor
timestamp: August 23, 2017, 03:45:21 pm
content: Quote from: T3sl4co1l on August 23, 2017, 02:54:34 pmErr, would you like to test that statement with a bit of ABS?

author: joseph nicholas
author_rank: Frequent Contributor
timestamp: August 23, 2017, 04:30:41 pm
content: If you live in Mexico and other south of the US border, you can get something to try on your boards. Just go to any liquor store and ask for "alcohol". Bring a jar or bottle and you get a quart for less than 1 dollar. Hope this helps.

author: ebastler
author_rank: Super Contributor
timestamp: August 23, 2017, 04:31:30 pm
content: Quote from: T3sl4co1l on August 23, 2017, 02:54:34 pmI beg to differ. Maybe you got your chemicals mixed up?Quotehttps://en.wikipedia.org/wiki/Acetone

author: meeder
author_rank: Regular Contributor
timestamp: August 23, 2017, 04:37:58 pm
content: I still remember someone cleaning his safety glasses with acetone...

author: Bud
author_rank: Super Contributor
timestamp: August 23, 2017, 04:40:59 pm
content: Look for ethanol fuel at fireplace stores and fireplace sections in big box stores. In Canada we have Bio Fuel brand which is 95% ethanolhttp://www.canadiantire.ca/en/pdp/bioflame-ethanol-3-78l-0643537p.htmlAlso go to woodworking stores and look for ethanol based lacquer thinners such as this onehttp://www.leevalley.com/en/Wood/page.aspx?p=20107&cat=1,190,42942

author: BBBbbb
author_rank: Unknown
timestamp: August 23, 2017, 04:45:12 pm
content: If he has trouble finding good IPA and alcohol, I doubt methanol, that some of you mentioned, is easier to acquire. It's usually a controlled substance.White residue after solvents could easily be due to too much water acquired from the humid air, especially if you keep you IPA/acetone in huge bottles for a long time and keep it opened while working. Best practice is small bottles and buy new ones every few months, unless you use it in big quantities.Nail varnish removers do have acetone but also oil, and if you think acetone is aggressive on materials you should try the remover, it's terrible and would not recommend it for any use.Good quality IPA (cat. 2-5) might be available in professional cosmetic shops, not sure what they use it for, but I find it there and for a good price too.

author: plazma
author_rank: Frequent Contributor
timestamp: August 23, 2017, 04:49:56 pm
content: Quote from: IanMacdonald on August 23, 2017, 03:27:43 pmNope. Acetone is C3H6O and MEK is C4H8O. They are quite similar in properties but still different chemicals.

author: rdl
author_rank: Super Contributor
timestamp: August 23, 2017, 05:30:52 pm
content: For most substances that are alcohol soluble, ethanol will work better than isopropanol (IPA).Ethanol is the alcohol people drink. To sell it as an industrial solvent and avoid expensive liquor taxes it must be made undrinkable or "denatured". There are many things used to denature it. Some may leave a residue others will not. The last place I worked bought ethanol by the tanker load. It was denatured by adding 5% isopropanol. It was anhydrous and had a very low dissolved solids specification. It left no significant residue when dried.If you decide to try alcohol from a liquor store get 200 proof "pure grain alcohol". It will be fairly pure ethanol and expensive. Anything else you can buy there will probably be too dilute and contaminated with other ingredients to be useful.Acetone attacks very few electronic components. This is only because of the types of plastic used to make those components. Acetone is a strong and aggressive solvent. Acetone is not MEK. They are two different chemicals.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 23, 2017, 07:21:21 pm
content: Quote from: Monkeh on August 23, 2017, 03:45:21 pmPoorly worded. I meant plastics used for components. Few if any are ABS. (Only thing that comes to mind: mechanical parts that aren't nylon or better. ABS might be used for guide rails, support brackets, light pipe mounts, etc. These are usually snapped in place after washing, so it's not a problem in manufacture.)Note that polystyrene capacitors are very solvent sensitive, but, they're practically unavailable today, so they aren't a problem. If you're using them in some special project, you'll know better.Again, RTFDS for solvent compatibility.Tim

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 23, 2017, 07:22:30 pm
content: Quote from: IanMacdonald on August 23, 2017, 03:27:43 pmAcetone is dimethyl ketone, or propan-2-one if you like to be even more precise.Tim

author: jmelson
author_rank: Super Contributor
timestamp: August 23, 2017, 07:32:13 pm
content: Quote from: sasa on August 23, 2017, 12:15:50 pmIn the US, we can buy 100% denatured alcohol at the hardware store. It is used for thinning paints. They likely have IPA and methyl (wood) alcohol also.Jon

author: Cerebus
author_rank: Super Contributor
timestamp: August 23, 2017, 07:40:23 pm
content: Quote from: Monkeh on August 23, 2017, 03:45:21 pmOr some rare, and getting harder to find, polystyrene capacitors?

author: David Hess
author_rank: Super Contributor
timestamp: August 23, 2017, 08:02:04 pm
content: Toluene is another possibility but it also attacks some plastics. Common rosin flux thinner used to be 50/50 isopropyl alcohol and toluene.In the past we used lacquer thinner without problems for cleaning boards after soldering but like acetone, it will attack many plastics. If necessary, certain parts like polystyrene capacitors and DIP switches were soldered on afterward and cleaned by hand. Parts which are not sealed like DIP switches should not be submerged in flux cleaner anyway.I do not know if it would work but naphtha as found in lighter fluid might be suitable. It has the virtue of not attacking plastics and is commonly used in plastic safe cleaners and lubricants.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: August 23, 2017, 08:31:47 pm
content: It can be also helpful to know or look up which substances have a pharmaceutical relevance.(EU = Ph. Eur., US = USP-NF, etc.) Because everything that is in there is available through a pharmacy, even if they don't know or whatever. I needed petroleum for filing aluminium parts and I did not want to buy litres of it because too much combustibles, so I got my Apotheke to order me nice little 250ml bottles.And they can obtain both IPA and Ethanol which is nearly water-free.

author: wraper
author_rank: Unknown
timestamp: August 23, 2017, 09:22:59 pm
content: Quote from: T3sl4co1l on August 23, 2017, 07:21:21 pmStill a very good chance to wash off markings from many parts.

author: Bud
author_rank: Super Contributor
timestamp: August 23, 2017, 09:58:21 pm
content: Quote from: jmelson on August 23, 2017, 07:32:13 pmIt can't be 100% if it is denatured. Unless you mean there no alcohol left in it!

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 23, 2017, 10:09:45 pm
content: Quote from: IanMacdonald on August 23, 2017, 03:27:43 pmAcetone:https://en.wikipedia.org/wiki/Acetoneis NOT methyl ethyl ketone:https://en.wikipedia.org/wiki/ButanoneMEK has one more carbon on a side chain.

author: David Hess
author_rank: Super Contributor
timestamp: August 23, 2017, 11:05:14 pm
content: Quote from: wraper on August 23, 2017, 09:22:59 pmI only rarely had acetone or lacquer thinner affect parts or take the markings off but they will remove most writing from a printer or a pen. We had special ink for our identification stamps which was only slightly affected.My ultrasonic cleaner with hot water and a little bit of dish soap sure took the markings off of the 741 ICs and some of the plastic packaged transistors on a couple of my power supply boards though.

author: Vgkid
author_rank: Super Contributor
timestamp: August 23, 2017, 11:27:56 pm
content: Quote from: David Hess on August 23, 2017, 11:05:14 pmThat same method will also remove the paint from hp power supplies.

author: Ash
author_rank: Regular Contributor
timestamp: August 23, 2017, 11:51:45 pm
content: Quote from: wraper on August 23, 2017, 01:44:14 pmMy apologies -you're correct. Late night slip up..IPA is isoproyl.I was thinking of DAA - denatured absolute alcohol.http://www.recochem.com.au/index.php/products/industrial_products/ethanols/item/daa_industrialThis stuff doesn't leave much if anything of a mark. You may be using something that isn't as pure. Also If you're getting crap left behind, perhaps you need to wash and rinse off to remove the residue. I've had some stuff on older boards from test gear that was hard to clean, it too a few goes.Ash.

author: ahbushnell
author_rank: Frequent Contributor
timestamp: August 24, 2017, 01:42:32 am
content: India Pale Ale (IPA)

author: Ian.M
author_rank: Super Contributor
timestamp: August 24, 2017, 01:57:06 am
content: It might work in an ultrasonic cleaning tank, but I think you'd have a problem with excessive foaming, and at only 5% alcohol, you'd better be using a water washable flux.<Need Beer Smiley>

author: jmelson
author_rank: Super Contributor
timestamp: August 24, 2017, 02:52:15 am
content: Quote from: Bud on August 23, 2017, 09:58:21 pmRight, for pedantic purposes, it must be some 97% or better.Jon

author: IanB
author_rank: Super Contributor
timestamp: August 24, 2017, 02:52:54 am
content: If you drink enough IPA you won't care about the flux residues on your circuit boards anymore

author: poorchava
author_rank: Super Contributor
timestamp: August 24, 2017, 06:22:42 am
content: I actually prefer to use nitrocelulose paint thinner (commonly known in middle and eastern Europe as "nitro thinner").Its composition is not standardized, but it commonly contains about 70% toluene and 30% acetone. Manufacturers also add stuff like xylene, ethylobenzene, methyl acetate, ethyl acetate, and various alcoholes.It generally smells worse than IPA, but is much more effective at removing stuff and evaporates much more quickly. It is also much less hygroscopic than IPA, so it doesn't leave the white residue.

author: ebastler
author_rank: Super Contributor
timestamp: August 24, 2017, 09:51:31 am
content: Quote from: IanB on August 24, 2017, 02:52:54 amActually you won't care about anything anymore...And you don't have to drink a whole lot; the lethal dose is around5mg/kg5g/kg body weight.EDIT: Fixed three-orders-of-magnitude typo -- thanks jpanhalt!

author: G7PSK
author_rank: Super Contributor
timestamp: August 24, 2017, 09:55:18 am
content: Lighter petrol (benzine)

author: jpanhalt
author_rank: Super Contributor
timestamp: August 24, 2017, 10:02:20 am
content: Quote from: ebastler on August 24, 2017, 09:51:31 amYou are only three orders of magnitude off. Lethal oral dose (LD50) is more like 5g/kg in mouse, rabbit, and rat. Volunteers are needed to establish the limit for humans.Considering some of the other "chemistry" advice in this thread, though, that is not too bad.

author: ebastler
author_rank: Super Contributor
timestamp: August 24, 2017, 10:09:32 am
content: Quote from: jpanhalt on August 24, 2017, 10:02:20 amOops, sorry -- small typo, but with a major impact on the content...Thanks for catching that one! I'll add an edit to my post above.

author: sasa
author_rank: Regular Contributor
timestamp: August 24, 2017, 10:54:23 am
content: Thanks to all for comments.Actually, some suggestions are more practically feasible for me, as finding isopropyl alcohol (and based solutions on it) at different places than electronic stores. Personally, I would never though it is possible to connect cosmetic shop with isopropyl alcohol... Certainly weird, but also worth to try.Thanks again.

author: Muttley Snickers
author_rank: Unknown
timestamp: August 24, 2017, 10:55:35 am
content: 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.

author: Cerebus
author_rank: Super Contributor
timestamp: August 24, 2017, 11:46:10 am
content: Quote from: ebastler on August 24, 2017, 09:51:31 amI think you'll find he was referring to theIndiaPaleAlevariety, in which case the LD50 is a bit over 12 bottles (based on Green King IPA, 500ml bottles, a 70kg male human and the unrealistic situation of taking it all at once, rather than over some time - the latter allowing the beginning of the 'dose' to have been metabolised well before you get to the end of the 'dose'). Of course beer can have an LD99 as low as one bottle, if that bottle is applied with enough force.

author: chris_leyson
author_rank: Super Contributor
timestamp: August 24, 2017, 11:55:58 am
content: I've sometimes used Electrolube flux cleaner for more stuborn deposits, don't know why they bother to call it lead free ? Always wondered what was in it apart from the obvious limonine and found a data sheethttp://www.farnell.com/datasheets/1526102.pdf.

author: Muttley Snickers
author_rank: Unknown
timestamp: August 24, 2017, 11:56:35 am
content: I could plaster myself with alcohol wipes.

author: tooki
author_rank: Super Contributor
timestamp: August 24, 2017, 05:23:07 pm
content: Quote from: Bud on August 23, 2017, 04:40:59 pmI'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.)Here in Switzerland, most solvents cost a fortune at retail, to the point that commercial flux remover is only slightly more expensive than IPA. ::sigh::I'd love to use ethanol instead of IPA, since the smell is far less offensive, but non-denatured ethanol (i.e. 96% alcohol from the liquor store) costs $70/liter.Meanwhile you can get 40% vodka for $12/l, meaning just $30/l of pure alcohol, if only the water could be removed easily.

author: Ian.M
author_rank: Super Contributor
timestamp: August 24, 2017, 06:07:14 pm
content: Quote from: tooki on August 24, 2017, 05:23:07 pmSeparating 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.

author: G7PSK
author_rank: Super Contributor
timestamp: August 24, 2017, 08:21:59 pm
content: Quote from: Muttley Snickers on August 24, 2017, 10:55:35 amI 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.

author: David Hess
author_rank: Super Contributor
timestamp: August 24, 2017, 09:37:54 pm
content: Quote from: tooki on August 24, 2017, 05:23:07 pmQuote from: Ian.M on August 24, 2017, 06:07:14 pmI 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.

author: Cerebus
author_rank: Super Contributor
timestamp: August 24, 2017, 10:32:39 pm
content: Quote from: David Hess on August 24, 2017, 09:37:54 pmThis 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.

author: jpanhalt
author_rank: Super Contributor
timestamp: August 24, 2017, 10:44:31 pm
content: Quote from: Ian.M on August 24, 2017, 06:07:14 pmDid 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/AzeotropeApropos 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

author: IanB
author_rank: Super Contributor
timestamp: August 25, 2017, 12:52:20 am
content: 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.

author: Bud
author_rank: Super Contributor
timestamp: August 25, 2017, 01:58:46 am
content: Quote from: tooki on August 24, 2017, 05:23:07 pmThe Bio Flame one seems to only be ethanol/water or ethanol/propanol mixture.

author: Ian.M
author_rank: Super Contributor
timestamp: August 25, 2017, 02:25:49 am
content: @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).

author: nanofrog
author_rank: Super Contributor
timestamp: August 25, 2017, 04:11:27 am
content: Quote from: IanB on August 25, 2017, 12:52:20 amAccording to the 11 July, 2014 revision of theMSDSfor KleenStrip Green Denatured Alcohol, the composition is...CAS# Concentration1. 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 revisionMSDSfor KleenStrip Denatured Alcohol is...CAS# Concentration1. Ethyl alcohol {Ethanol} 64-17-5 30.0 - 50.0 %2. Methanol {Methyl alcohol; Carbinol; Wood alcohol} 67-56-1 40.0 - 60.0 %

author: tooki
author_rank: Super Contributor
timestamp: August 25, 2017, 08:30:47 am
content: Quote from: Cerebus on August 24, 2017, 10:32:39 pmMy 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!)

author: tooki
author_rank: Super Contributor
timestamp: August 25, 2017, 08:33:37 am
content: 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???

author: nanofrog
author_rank: Super Contributor
timestamp: August 25, 2017, 08:37:47 am
content: 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.

author: tooki
author_rank: Super Contributor
timestamp: August 25, 2017, 08:42:39 am
content: 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!

author: Ian.M
author_rank: Super Contributor
timestamp: August 25, 2017, 09:36:39 am
content: 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 - seehttp://www.forensicscience.pl/pfs/63_zuba3.pdfhowever 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

author: ebastler
author_rank: Super Contributor
timestamp: August 25, 2017, 09:39:15 am
content: Quote from: tooki on August 25, 2017, 08:30:47 amI 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.

author: Ian.M
author_rank: Super Contributor
timestamp: August 25, 2017, 09:57:33 am
content: 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

author: BBBbbb
author_rank: Unknown
timestamp: August 25, 2017, 11:39:56 am
content: Quote from: tooki on August 25, 2017, 08:33:37 amEdmund 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.

author: tooki
author_rank: Super Contributor
timestamp: August 25, 2017, 11:49:41 am
content: Quote from: ebastler on August 25, 2017, 09:39:15 amHave 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.

author: tooki
author_rank: Super Contributor
timestamp: August 25, 2017, 11:52:21 am
content: Quote from: BBBbbb on August 25, 2017, 11:39:56 amThanks, 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.)

author: Cerebus
author_rank: Super Contributor
timestamp: August 25, 2017, 01:51:00 pm
content: Quote from: tooki on August 25, 2017, 08:30:47 amAs 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.

author: ebastler
author_rank: Super Contributor
timestamp: August 25, 2017, 04:31:34 pm
content: Quote from: tooki on August 25, 2017, 11:49:41 amI 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. Beingverybitter 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.

author: MLXXXp
author_rank: Frequent Contributor
timestamp: August 25, 2017, 06:07:19 pm
content: 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)?

author: Old Don
author_rank: Regular Contributor
timestamp: August 28, 2017, 08:54:07 pm
content: 190 proof moonshine can be had under the counter in many locations - just saying.

author: boffin
author_rank: Unknown
timestamp: August 28, 2017, 09:23:03 pm
content: Quote from: sasa on August 23, 2017, 12:15:50 pmI 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.

author: Ian.M
author_rank: Super Contributor
timestamp: August 28, 2017, 10:24:48 pm
content: 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.

author: Old Don
author_rank: Regular Contributor
timestamp: August 29, 2017, 12:40:37 am
content: Different countries of the world have different names for isopropyl alcohol:https://en.wikipedia.org/wiki/Isopropyl_alcohol

author: plazma
author_rank: Frequent Contributor
timestamp: November 10, 2017, 06:31:53 pm
content: Quote from: Ian.M on August 28, 2017, 10:24:48 pmAcetone does dissolve some epoxies. One way to fix epoxy potted electronics is to dissolve the potting agent with acetone (like C64 power supplies)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 10, 2017, 08:24:34 pm
content: I wouldn't say dissolve, swell maybe. Epoxy is a cross-linked gel, it cannot be dissolved. Unless what you've got there ain't epoxy!Tim

author: IanB
author_rank: Super Contributor
timestamp: November 10, 2017, 10:01:02 pm
content: Acetone does however dissolve or loosen cyanoacrylate adhesives (superglue). This has been a lifesaver for me when the glue has gone where it shouldn't, or has stuck my fingers together.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 10, 2017, 10:20:52 pm
content: FYI, if you do want to seriously swell and soften (and make easier to excavate, but still not dissolve) epoxy, or silicone, other difficult substances like that: methylene chloride (good old fashioned toxic paint stripper!) is the go-to. Use carefully on PCB, because it'll destroy the laminate, too!Tim

author: M4trix
author_rank: Frequent Contributor
timestamp: November 10, 2017, 10:33:02 pm
content: Quote from: T3sl4co1l on November 10, 2017, 10:20:52 pmQuote

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 11, 2017, 12:52:13 am
content: Quote from: M4trix on November 10, 2017, 10:33:02 pmNot quite as lively as carbon tet, but surely best used sparingly.Tim

author: nanofrog
author_rank: Super Contributor
timestamp: November 11, 2017, 02:33:40 am
content: MEK is nice to have on hand as well IME, assuming it's available in your location.

author: Cerebus
author_rank: Super Contributor
timestamp: November 11, 2017, 03:10:41 am
content: I'm getting a sense ofdeja vu. Haven't all these solvents already had a mention in this thread? Or was it another similar thread? 'The solvent thread' seems to be a recurrent one, so it's difficult to tell.Perhaps it's time for 'common electronics solvents' thread designed, from the start, to turn into a sticky thread and somewhat carefully curated to try and avoid some of the chemistry/toxicity gaffes that seem to plague this recurrent subject?