Is it possible to clean ICs with Pure Alcohol ?

russellz: Here, in France, you can buy "Alcool à brûler" in any supermarket. It consists of 90 to 95% ethanol with 5 to 10% methanol. Both are highly volatile and leave no residue making it very good for cleaning.

Russell.

exactly mine is volatile that's why i had courage to use it ! you can put alcohol all over yourself and after a bit of time nothing is left :)

Boardburner2: Aqua i think is water according to cosmetic companies.

Alcohol type should be specified.

Over here rubbing alcohol uses isopropyl alcohol at 40 % as a denaturant.

Its not very nice for dust ime it evaporates slowly and sludges the dust making it difficult to vacuum.

Cleaning dust off psu's especially hv ones can be very annoying.

Not allowed to use compressed air as it blows it all over the place just a hoover.

industrial meths (brushed with adequate ventilation) used to be my preferred solution.

Cant have water in it.

Someone suggested colemans fluid but iv never been sure about that to try it.

edit to be clear i was using pure isopropyl not rubbing alcohol.

aqua is latin yes and it means water for sure, it is used in italian and spanish but different letters, in spanish acqua and in italian agua

well i tried to clean the ICs as i said before and everything works fine, the composition doesn't tell which alcohol they are using but it says the percentage is 95% that's all on the bottle

CrossRoads: Anhydrous alcohol works well, 99.9%. Dries quick thru evaporation as there is next to nothing in it. Use ventilation if cleaning a lot of cards. http://www.mgchemicals.com/products/cleaners/electronic-cleaners/isopropyl-alcohol-824/

the one i use cleans 99.9% too and dries very quickly so i guess according to this info my ICs are safe :) ?

Is there really an advantage in using 99.9% isopropanol vs. the 91% solution that is readily available? A 91% v/v solution is the azeotrope. A nearly pure solution would be somewhat more volatile but temperature and air flow are probably a lot more important than that slight difference. I wonder how much moisture the anhydrous stuff absorbs before it evaporates?

Anhydrous isopropanol costs $10 for a 500ml bottle at digikey, not including shipping. The other day I walked down to the local drug store and bought a 480ml bottle of 91% isopropanol/water for under $3.

Or does it make a noticeable difference?

I find the "dryer" alcohol cuts thru the flux from rosin core solder quite well. Lesses %s need multiple passes to clean. My local electronics supplier has it in gallon bottles. I picked one up at some point, we put a few ounces at a time in a small pump jar (not sure what the actual name is, same square bottle with spring top, push down a couple times and top fills with some alcohol for the cleaning brush - same thing our shop at work uses for cleaning up reworked boards). http://www.mouser.com/ProductDetail/Menda/35309/?qs=%2fha2pyFadugResYH%252b75ZqvYV6knOqbetNdKoUVscgdY%3d which my supplier also had, along with a hog hair bursh http://www.mouser.com/ProductDetail/MG-Chemicals/857/?qs=sGAEpiMZZMvJqaFk9BIiv6jhjM0Pk6JzPq2RhIeIS6c%3d This one works well as the bristles are longer and the pins of shields can go thru the bristles. Hopefully the forum/IE11 won't stick extra http stuff at the front of the links ...

Good stuff! Use in a ventilated area.

ISOPROPYL ALCOHOL: ELECTRONICS CLEANER 824-LIQUID

Page 10 of 14 Date of Creation: 01 Aug 2013 / Ver. 2.01

|
Skin corrosion/irritation |
Causes mild skin irritation based on Draize tests on rabbits. Prolonged or repeated skin contact may cause dermatitis | | - | - | |
Serious eye damage/irritation |
Causes moderate to severe eye irritation based on Draize tests on rabbits | |
Sensitization (allergic reactions) |
No evidence of sensitization | |
Carcinogenicity (risk of cancer) |
Not classified or listed as a carcinogen by IARC, ACGIH, CA Prop 65, or NTP | |
Mutagenicity (risk of heritable genetic effects) |
No data available | |
Reproductive Toxicity (risk to sex functions) |
No data available | |
Teratogenicity (risk of fetus malformation) |
No data available | |
STOT-single exposure |
Propan-2-ol can affect the central nervous system by inhalation causing drowsiness or dizziness. | |
STOT-repeated exposure |
No data available | |
Aspiration hazard |
Not classified as aspiration hazards. |

So you think the 99% concentration has a noticeably greater solvent power than the 91%? It would be interesting to see a blind test.

I just know it took what seemed like 3 cleanings for the sticky feel to go away, and longer to dry.

Here, in France, you can buy “Alcool à brûler” in any supermarket. It consists of 90 to 95% ethanol with 5 to 10% methanol. Both are highly volatile and leave no residue making it very good for cleaning.

Boardburner2:
equivalent here is rubbing alcohol.
Composition is different though its pretty good but im sure that there is something else in it , it feels slightly oily after evaporation

The french type cannot be imported to the uk without a licence, i tried once.

Incorrect. “Rubbing Alcohol” is isopropyl, water, and generally some kind of oil.

What he describes is called denatured alcohol in the USA. Ethanol with methanol and often a few other solvents. Works great as a degreaser, but attacks some plastics.

I generally use 99% isopropyl for cleaning electronics, but also use denatured alcohol for some tasks.

jboyton: So you think the 99% concentration has a noticeably greater solvent power than the 91%? It would be interesting to see a blind test.

The key thing is that it leaves less water behind.

polymorph: The key thing is that it leaves less water behind.

The solution doesn't evaporate?

The alcohol evaporates quickly, the water not as quickly.

Not for a 91% solution. The vapor and liquid have the same composition. That's why it's impossible to obtain a higher concentration via simple distillation. I think that also means it is slightly more volatile than pure isopropanol. The 91% stuff should actually evaporate as fast or a little faster.

But maybe the higher concentration makes it a better solvent.

Citation?

But... the 99% starts out with less water in it. So even if the alcohol evaporates more quickly, it reaches dynamic equilibrium at 91% and continues to evaporate at 91%, but it has reached that point more quickly.

This is what I use. Get it at Fry’s or online, or seek a similar alternative.

I agree with Crossroads. It usually takes 3 cleanings to get rosin flux “perfectly” cleaned off. However, you don’t need it perfect unless you are selling it or showing it to investors. Once is pretty good.

ISO1L.jpg

polymorph: Citation?

But... the 99% starts out with less water in it. So even if the alcohol evaporates more quickly, it reaches dynamic equilibrium at 91% and continues to evaporate at 91%, but it has reached that point more quickly.

I don't have a citation. And my chemistry is pretty poor.

This is from wikipedia:

|500x448

The azeotrope is at a mole fraction of about 0.68. The molecular weights of isopropanol and water are 60.1 and 18.0 g/mol respectively. So the weight fraction of isopropanol at the azeotrope is approximately:

(0.68*60.1) / (0.68*60.1 + (1-0.68)*18.0) = 0.88

Converting that to volume is more complicated because there is contraction upon mixing. But if you ignore that you can get sort of close. The room temperature densities of isopropanol and water are 0.79 and 1.00g/cm3, so:

(0.88/0.79) /(0.88/0.79 + (1-0.88)/1.00) = 0.90

My seat of the pants calculation puts the azeotrope at 90% v/v. But that can't be right since the drug store sells isopropanol/water at 91%. The volume contraction or my inaccurate read of the chart in wikipedia have thrown off the value slightly.

I'm surprised it's so hard to find an online reference to the v/v percentage. But here's one.

You can't distill past the azeotrope using normal methods. But if you manage to get to a higher concentration by other means then the solution will have a vapor that is enriched in the less volatile component. That is, the water will vaporize faster than the alcohol in a 99% isoprop. soln.

But the azeotrope is a boiling point minimum; hence a vapor pressure maximum. So evaporation rate would be higher for the less concentrated stuff. I'm not convinced this matters that much. And eyewitness accounts of evaporation rate are subject to bias.

All that said, it could well be that pure isopropyl alcohol is superior to a 91% mixture, I really don't know. I wouldn't be surprised if some other solvent would be better overall for cleaning the gunk off of PCBs.

jboyton: I wouldn't be surprised if some other solvent would be better overall for cleaning the gunk off of PCBs.

There are specific formulations for that. At least the manufacturers think they are better. They are certainly a bit more expensive than alcohol though. OP could give this a try and get back to us. Fry's sells it also.

http://www.all-spec.com/products/4140-1L.html

FluxRemover.jpg|300x300

The MSDS says:

2015-09-29_19-26-24.jpg

They will be selling air next.

.

The composition of the 4140 flux remover varies by country. But ethanol seems to be the main ingredient. That's kind of interesting. I asked about that in another thread, whether ethanol had any advantages/disadvantages for cleaning as compared to IPA.

Maybe I will pick up a bottle of it next time at Fry's and do a blind scrub-off test. :)