Methylated spirit vs IPA

[Bored@Work]

People have been injured by pouring alcohol on or near a flame causing a big fireball, especially when topping up an alcohol burner that is still alight.

People do that even when there is a visible flame, i.e. ethanol. We had e series of severe accidents last Christmas. Table "bio fireplaces" became popular, because they make such a nice mood lighting and there was an influx of cheap table bio fireplaces from China. These "bio fireplaces" are ethanol burners.

Some people managed to wipe the burner from the table, spilling burning ethanol around. Others bought cheap Chinese stuff and then had so learn the burner got so hot it burned through the table. But the most common way to kill or almost kill themselves and to burn down the house was trying to refill a burner while it was still burning.

[oPossum]

Isopropyl Alcohol

[Kozmyk]

My dad used to rub Meths into his hands to harden the skin before gardening.

My favourite general purpose solvent is Isopropyl Alcohol (99.9% preferred to the 70%with water).
I find IPA shifts most flux residues with a little rubbing; most importantly it doesn't attack the soldermask or screenprinting on PCBs.
 It also insinuates itself under hot glue so it's great for removing that stuff.
I first used it in recording studios to clean the tape heads without attacking the resins holding the laminations together.

I keep some Acetone handy which is great on metals but will melt a lot of plastics or at least make their surfaces sticky.
Colclene used to be some trichloroethylene variant but I think it's moved on to some more eco-friendly formulation now. Very light solvent leaves no trace.
Servisol 10 is my switch cleaner, good cleaning properties with a little lubricant residue.
Good old WD40, Castrol DWF and other petroleum based is fine for mechanical work but can make the inside of a potentiometer go all gooey.
Of course most plastics meant for automobile applications should tolerate WD40 as part of their fuel resistant properties.

I'm just beginning to learn that you can thin epoxy resin with both IPA and acetone.

[Gall]

The biggest difference between either pure or methilated ethanol and IPA is its activity.

Ethanol (pure or meths) tends to dissolve some resins, varnishes and even plastics. IPA doesn't.

But IPA stinks.

[ejeffrey]

Generally my order of choice for solvents is water, IPA, acetone, methanol.  Water is too often overlooked.  If water won't damage your device, it is usually the best thing to start with.  It is very polar, so it dissolves a lot of things the organic solvents are not so good at.  If you use DI water and have no pockets that can trap water, it is ok to let it air dry.  Gentle heating will speed the process.  Otherwise, follow with IPA and blow off with compressed air.  This will do a pretty good job of displacing the water so it doesn't leave its dissolved salts on the board.  Acetone is the heavy duty basic solvent, but is the most likely to damage your device.  Methanol is the most heavy duty alcohol, and is good to use when IPA isn't strong enough and you can't use acetone.  Both methanol and acetone evaporate very quickly, which can be annoying -- if it evaporates too fast it will just redeposit the crud it dissolved.  I don't usually use ethanol because it can be hard to find pure. 

Mixed solvent cocktails like paint thinners and grease removers can be very effective, but they are not very clean themselves.  You may need to follow with water and/or alcohol to get a really clean surface.  Another factor here is that lots of devices specify solvent resistance for alcohols and acetone, so you can be more confident it won't do any damage.  Other solvents may be more of a gamble.

[Zero999]

ok ok i got the content for "my thinner" toluene 60%, ketone 20%, other solvent 20%. this is the best pcb/flux cleaner i have so far from local, but it still leave slight residue, waterish like that difficult to evaporate, i need to use a blower to get rid of it. maybe i'm talking different vocabulary here, but hey its not my fault, its the manufacturer wrote on it.

It may be a great solvent but it's toxic, toluene can cause blindness, brain damage and mental retardation. Your mixture probably also contains benzene which is a deadly carcinogen, much worse than any of the ingredients listed. Use only in a well ventilated area, wear gloves and obviously don't drink it.

[IanB]

Use only in a well ventilated area, wear gloves and obviously don't drink it.

Just like unleaded petrol (gasoline) then? 

(When they took the lead out of petrol they had to put in other things like toluene and benzene to keep the octane rating up.)

[ElektroQuark]

Toluene mixes sometimes also have xylene. They make a good paint thinner/remover but are very toxic. A well ventilated area and protection goggles and gloves are highly recommended.

[IanB]

I have just discovered that while IPA when used with a rag will nicely clean flux spills off my work bench, IPA when used with a horse hair brush and a gentle scrubbing action will not remove flux residues from a PCB. I guess I'm off to the hardware store to find some acetone...

[Kozmyk]

I have just discovered that while IPA when used with a rag will nicely clean flux spills off my work bench, IPA when used with a horse hair brush and a gentle scrubbing action will not remove flux residues from a PCB. I guess I'm off to the hardware store to find some acetone...

IPA on a cotton bud will shift post soldering flux residue from a PCB with bit of scrubbing. You need more friction than a brush can provide to get it going.
Depending on what flux you have YMMV.
Be prepared for the acetone to remove more than you bargained for.

[IanB]

IPA on a cotton bud will shift post soldering flux residue from a PCB with bit of scrubbing. You need more friction than a brush can provide to get it going.
Depending on what flux you have YMMV.
Be prepared for the acetone to remove more than you bargained for.

I used a 50/50 mixture of acetone and IPA with decent results. I was cleaning the back of a through-hole board and I didn't let the solvent mix get on the component side of the board.