alternative to isopropyl alchol - cleaning circuits ater soldering - Page 1
Forum section: electronics / beginners

author: amateur_25
author_rank: Regular Contributor
timestamp: February 11, 2012, 12:58:21 pm
content: HiI frequently visit FABlab which is hack space funded by a charity for both hobbyists and commercial purposes.Being an organisation they're covered by heath and safety laws. They have banned me from using isopropyl alchol.Is there anything else I can use to clean my circuits? My circuits frequently need cleaning due to my bad soldering skills.I know there're solders with water soluable fluxes however am unsure is this suitable? I thought electricity and water don't mix well andit can damage pcbs?

author: metalphreak
author_rank: Frequent Contributor
timestamp: February 11, 2012, 01:14:01 pm
content: http://au.element14.com/chemtools/ct-pcbw5l/pcb-wash-water-based-5l/dp/182778201?Ntt=182-778201http://www.farnell.com/datasheets/608322.pdfThere's tons of different brands of this kind of stuff. Chemtools makes this in Australia so I'm not sure if its available worldwide.

author: vk6zgo
author_rank: Super Contributor
timestamp: February 11, 2012, 01:31:18 pm
content: Quote from: amateur_25 on February 11, 2012, 12:58:21 pmWhat the hell is wrong with isopropyl alcohol?It seems to me to be the least noxious of all the solvents which are commonly used.Maybe they think you're drinking it!

author: Unknown
author_rank: Unknown
timestamp: February 11, 2012, 01:41:35 pm
content: There are plenty commercial flux cleaners which are likely to be less volatile and less inflammable. Not sure if it's any better than IPA for humans, IPA is fairly safe as long as you don't drink it and the area is well-ventilated.Water soluble fluxes are very aggressive, cleaning is not optional like with no-clean or RMA fluxes. They are often used in industry since using large amounts of organic solvents, often more aggressive than IPA, is a safety issue and makes waste disposal expensive. Demineralized water should be fine as long as you clean the board before adding any components that might trap water, like transformers, pots and switches. You should probably bake the boards at moderate temperatures to get rid of moisture.How about just using no-clean flux? It may not be pretty, but the flux shouldn't be an issue unless your circuits are very high impedance.

author: Short Circuit
author_rank: Frequent Contributor
timestamp: February 11, 2012, 01:46:05 pm
content: Use a small blade screwdriver to scrape the flux remains off.After some practising, this can be done without scratching the soldermask.Then, for the finishing touch, if desired, you could probably get away with thealcohol content from a spray of deodorant.

author: IanB
author_rank: Super Contributor
timestamp: February 11, 2012, 05:34:16 pm
content: Yesterday I was reading a recommendation for pure grain alcohol (PGA) as a flux cleaner. This is 95% ethanol, 5% water. Apparently this cleans flux even better than IPA. But make sure it is pure alcohol and not denatured alcohol from the hardware store. Denatured alcohol contains contaminants like gasoline and is no good for cleaning.The easiest way to buy PGA is as the Everclear brand from a liquor store, if you can find it. Unfortunately California has banned it, which sucksIn California you can only obtain the version containing 25% water which does not work the same.In other countries like the UK the purple methylated spirits may be fine.

author: IanB
author_rank: Super Contributor
timestamp: February 11, 2012, 05:37:24 pm
content: If you are banned from using IPA, you might see if they will let you use "rubbing alcohol". This surely is safe, or it wouldn't be permitted for its medical uses.

author: wkb
author_rank: Super Contributor
timestamp: February 11, 2012, 05:45:33 pm
content: Quote from: IanB on February 11, 2012, 05:34:16 pmDenatured ethanol is typically made undrinkable by the addition of methanol. Not by adding gasoline.Denatured alcohol works just fine for cleaning PCBs.

author: Lightages
author_rank: Unknown
timestamp: February 11, 2012, 06:02:00 pm
content: Really? Isopropanol banned? Are they crazy? It is one of the safest, cheapest, and best understood solvents there is. Maybe the are mixing things up with methanol. You do not want that in constant contant with skin or breathe the vapors.

author: IanB
author_rank: Super Contributor
timestamp: February 11, 2012, 06:08:17 pm
content: Quote from: wkb on February 11, 2012, 05:45:33 pmIt depends what country you are in. In the USA denatured alcohol always contains gasoline. In the UK there is "methylated spirits" which contains methanol and a purple dye--however methylated spirits is unavailable in the USA.As a side note, many posters here fail to indicate which country they are in. It often makes provision of accurate answers quite difficult.

author: wkb
author_rank: Super Contributor
timestamp: February 11, 2012, 06:20:09 pm
content: Quote from: IanB on February 11, 2012, 06:08:17 pmIn .nl the equivalent of methylated spirits is typically called 'spiritus'. This is normally colored blue with some dye.Instead of methanol sometimes pyridine is used.

author: siliconmix
author_rank: Frequent Contributor
timestamp: February 11, 2012, 06:32:14 pm
content: i use cd cleaner cheap as chips

author: M. András
author_rank: Super Contributor
timestamp: February 11, 2012, 06:47:37 pm
content: i work in a drug(medicine) distribution company where we have pure alcohol for medical purposes if i remember right its 97% i will try to clean a pcb with it, i never tried to use it as a pcb cleaner cos expensive and evaporates quickly

author: Zad
author_rank: Super Contributor
timestamp: February 11, 2012, 07:35:22 pm
content: It sounds to me like some self-appointed "health and safety expert" has seen the word Alcohol and instantly had mental images of explosions, immense fires and hobos drinking meths.

author: Psi
author_rank: Super Contributor
timestamp: February 11, 2012, 11:30:40 pm
content: I have a spray can of jaycar circuit board cleaner.Unfortunately it tends to dull the solder mask and make it sticky for a while (probably slightly dissolving it).So i don't really recommend it.It removes flux perfectly well though.

author: sorin
author_rank: Frequent Contributor
timestamp: February 12, 2012, 12:46:05 am
content: I use ethanol (pure, 99%)you can buy it in pharmacy (I bay 1L for $3).

author: amspire
author_rank: Super Contributor
timestamp: February 12, 2012, 01:36:24 am
content: This is a weird thread - all the good answers, but we still do not know why the isopropyl alcohol was banned in the first place! Is it fumes, risk of poisoning, is it carcinogenic, religious reasons, fire risk? I could certainly understand an organization wanting to avoid uncontrolled flammable liquids on site. Perhaps it was just the packaging they didn't like, so a can of aerosol PCB cleaner or a child-safe bottle would be fine. Perhaps it was the quantity? They didn't want a 4 gallon can of it on the premises, but a small perfume spray bottle containing just a few milliliters would be fine.Anyway, I just don't see it as much of a problem. The residue on boards is largely a cosmetic problem only and there is no urgency to get it clean. Surely it is easy to clean the boards outdoors near the Fab Lab or at home. If they do not want the alcohol indoors, just don't take it indoors.Richard.

author: bfritz
author_rank: Regular Contributor
timestamp: February 12, 2012, 05:21:15 am
content: The main problem with alcohol as a cleaning solvent, is the flammability of the vapors, and the fact that a pure alcohol fire burns with a nearly invisible flame. Note that using a paper towel, and then throwing that in a trash container can allow vapors to collect, and then what happens if someone throws in something that ignites the vapors, or they spill over to something very hot, or a flame. An alcohol fire is quite sneaky, as it is very hard to see. In the US, to meet OSHA regulations in a commercial lab, we were required to have a flammable items disposal bin, and to empty the bin every day into a well ventilated container that was stored outside. We were also required to have a special storage location for items considered flammable. My guess is that the location is trying to sidestep such expenses, by simply saying not to use flammable items there. If it is like most ventures like this, they simply cannot afford the expense and hassle that occurs with flammable materials.I suggest going to items that are either no-clean, or water clean. Solder, solder-braid, and flux should all be bought that meet their requirements. They are not appreciably that much more, and will reduce the risk of fire from flammable materials. For the vast majority of circuits, the no-clean chemistry items are fine. Some of the no-clean items may leave a small amount of residue, but it tends to be small, and by design is not sticky and is not conductive. If you absolutely require the very least leakage currents possible, use the water clean items.Regarding your question about water and electronics...The issue is really about impurities in the water shorting out the electronics. I use an ultrasonic cleaner filled with deionized water to clean pcb's all the time. Pure water is a poor conductor of electricity. It is the impurities in the water that allow current flow. The important issue is that after cleaning, regardless of what solvent is used, to dry the board thoroughly. Note that just because the big flat areas are dry, does not mean underneath IC's and pins is dry. I suggest 15 minutes or so in a warm environment. We used a small toaster oven modified to sit at about 150F.Note that some components shoud not be immersed. Such items include certain switches, and connectors. Usually items where the capillary action of the water would allow contaminants to be carried into the device, but might make it difficult to dry out easily. For example dip switches that have a sealing tape in place allow for water cleaning, after which you peel off the tape to operate the switch.

author: westfw
author_rank: Super Contributor
timestamp: February 12, 2012, 08:05:42 am
content: QuoteThis is unlikely to be true. For most circuits, you can have a ugly, rosin-splattered board, and it will still work fine."Water-cleanable" fluxes are sort of worse; the fluxes are more corrosive than rosin, and MUST be cleaned off...Or you can take your board home and clean it there, at least while you can still buy Isopropyl. Perhaps outdoors, where the flammable vapors that present the "health and safety" problem will be minimized. I don't see why all operations need to be done AT the hackerspace...

author: PStevenson
author_rank: Regular Contributor
timestamp: February 12, 2012, 11:02:14 am
content: to celebrate a circuit well done I have a glass of brandy and I pour a bit on the PCB to clean it off haha

author: amyk
author_rank: Super Contributor
timestamp: February 12, 2012, 11:40:05 am
content: I can think of a lot more dangerous solvents for cleaning than alcohol... although I agree with bfritz's statement about flammability.

author: SeanB
author_rank: Super Contributor
timestamp: February 12, 2012, 01:09:40 pm
content: And there I was using TCE in 200l drums with an ultrasonic cleaner. Clean a PCB in 3 seconds in the vapour, and dissolve the board in 20 seconds in the boiling liquid. Was used because the boards were conformally coated, and this survived almost anything else. Drop in a carburettor that had 20 years of gunk on it ( or anything with hydraulic oil on it) for 1 minute and it came out scrubbed white and clean.I use alcohol ( meths) and a small container. If you are getting nagged use a 150 proof alcohol ( 25% water) and dry with an oven afterwards. I use a hot air gun.

author: siliconmix
author_rank: Frequent Contributor
timestamp: February 12, 2012, 04:57:52 pm
content: Quote from: Psi on February 11, 2012, 11:30:40 pmdoes it dull the solder aswell ?

author: westfw
author_rank: Super Contributor
timestamp: February 13, 2012, 12:43:37 am
content: QuoteHave you got a reference for that? It sounds like an old wives tale. As far as I can tell, denaturants are usually more specific substances designed to have particularly bad taste or digestive effects. Gasoline might contain the same compounds (or not), but gas is better thought of as "somewhat undefined mix of lighter hydrocarbons..."

author: grenert
author_rank: Frequent Contributor
timestamp: February 13, 2012, 01:54:58 am
content: Quote from: IanB on February 11, 2012, 06:08:17 pmSee the attached data sheets for two examples of denatured alcohol for sale in the US that do not contain gasoline. As wkb says, denatured alcohol means simply making ethanol undrinkable. This stuff is often used in science labs; a mix as crude as gasoline would not be suitable.

author: IanB
author_rank: Super Contributor
timestamp: February 13, 2012, 02:00:07 am
content: Quote from: westfw on February 13, 2012, 12:43:37 amAlcohol comes under Federal control in the USA. There are standard formulas normally required to be used for completely denatured alcohol (CDA), which is the stuff available for the public to buy in containers from a hardware store. See formula nos. 18, 19 & 20:http://edocket.access.gpo.gov/cfr_2011/aprqtr/pdf/27cfr21.23.pdfYou are correct that "gasoline" in this context may be a somewhat vague description, but it is generally stuff you might put in your car, one way or another.Industrial users are allowed more freedom, but the purer formulations are much more restricted in their distribution and use.

author: IanB
author_rank: Super Contributor
timestamp: February 13, 2012, 02:04:01 am
content: Quote from: grenert on February 13, 2012, 01:54:58 amIt is true. See the reference linked above.QuoteYour datasheets contain formulas for "specially denatured alchohol", SDA. These formulas are very restricted in their availability, for example to industry, food, cosmetics and pharmaceutical uses, and science labs. SDA is simply not available for the general public to purchase.

author: grenert
author_rank: Frequent Contributor
timestamp: February 13, 2012, 02:05:03 am
content: Well, that is an interesting reference, IanB. I guess there are a lot of different possible formulations out there.Gotta edit my prior post...

author: klafaille
author_rank: Newbie
timestamp: February 13, 2012, 03:41:32 am
content: I use 100% Acetone for cleaning flux off boards, works great, dries quick, it's cheap, and apart from flammability it's relatively harmless as long as you don't drink it or pour it in your eyes. Do watch out for certain plastics, and styrenes though, it'll mess them up quick. My Macbook can attest to that, (it also didn't like the soldering iron resting on it either).

author: Psi
author_rank: Super Contributor
timestamp: February 13, 2012, 05:32:21 am
content: Quote from: siliconmix on February 12, 2012, 04:57:52 pmyeah, maybe a little.What does that tell you?

author: siliconmix
author_rank: Frequent Contributor
timestamp: February 13, 2012, 10:59:37 am
content: thats what my cd cleaner does as well