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From: mickgeyver on 16 Jan 2010 15:39
On Jan 16, 11:24 am, John Larkin
<jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote:
> On Sat, 16 Jan 2010 07:12:35 -0600, "mook johnson" <m...(a)mook.net>
> wrote:
>
>
>
>
>
> >"Bob Eld" <nsmontas...(a)yahoo.com> wrote in message
> >news:hipunq$h3h$1(a)news.eternal-september.org...
>
> >> "Jon Slaughter" <Jon_Slaugh...(a)Hotmail.com> wrote in message
> >>news:hipkai$h07$1(a)news.eternal-september.org...
> >>> Is it safe to soak a pcb in acetone for several minutes to clean it up
> >>> all
> >>> the flux? The board only has some QFN's, SMT LED's, and passive SMT's.. I
> >>> imagine the acetone won't harm these packages?
>
> >> I think acetone, MEK and similar solvents are too harsh. They can dissolve
> >> or swell some plastics and may damage components.
>
> >> I use 91% isopropyl alcohol or denatured ethanol both are mild and work
> >> well. Use a small brush to loosen flux then wipe with a soft clean cloth.
> >> Re-do if any residue remains.
>
> >+1 on the alcohol recommendation.  use an acid brush with the bristles cut
> >down to 1/2" long.  squirt the alcohol inside the hollow brush handle and it
> >will wick down the bristles while you are scrubbing.
>
> IPA tends to leave white residue when used to clean rosin flux.
>
> >Once the heavy buildup is loose, put paper towel between the board and the
> >brush and repeat allowing the papertowel to absorb the liquified flus and
> >alcohol mix.
>
> For really clean boards, the last step should be a squirt rinse with
> clean solvent.
>
> John

IPA dissolves the rosin. The white stuff left over is not soluble in
IPA
but is soluble in water. I always follow IPA cleaning with a good
scrubbing
w/toothbrush and warm water then blow dry. Baking in warm oven is
optional.
al
From: who where on 16 Jan 2010 20:48
On Sat, 16 Jan 2010 14:55:18 -0500, Phil Hobbs
<pcdhSpamMeSenseless(a)electrooptical.net> wrote:

>On 1/15/2010 6:55 AM, Royston Vasey wrote:
>> "Jon Slaughter"<Jon_Slaughter(a)Hotmail.com> wrote in message
>> news:hipkai$h07$1(a)news.eternal-september.org...
>>> Is it safe to soak a pcb in acetone for several minutes to clean it up all
>>> the flux? The board only has some QFN's, SMT LED's, and passive SMT's. I
>>> imagine the acetone won't harm these packages?
>>
>> I'd say no and err on the safe side. Acetone can do nasty things to
>> plastics.
>>
>> Just soak in methylated spirits for a few minutes, much milder on both the
>> hardwar and your lungs and fingers.
>>
>> I'm not sure if the name methylated spirits is used globally - maybe you
>> know it as denatured alcohol ???

>Not the same thing. Methylated spirits is methanol, denatured alcohol
>is ethanol with something really bad tasting added--used to be benzene,
>now usually kerosene IIRC.

No, methylated spirits is ethanol with *some* methanol added.
Additionally, sometimes a bluish tint is added with dye, and at one
time at least pyridine was added to provide a distinctive odour.
From: mook johnson on 17 Jan 2010 11:06

"John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message
news:mtp3l5tmtk8jg16b7bt4n7f88s281tou7s(a)4ax.com...
> On Sat, 16 Jan 2010 07:12:35 -0600, "mook johnson" <mook(a)mook.net>
> wrote:
>
>>
>>"Bob Eld" <nsmontassoc(a)yahoo.com> wrote in message
>>news:hipunq$h3h$1(a)news.eternal-september.org...
>>>
>>> "Jon Slaughter" <Jon_Slaughter(a)Hotmail.com> wrote in message
>>> news:hipkai$h07$1(a)news.eternal-september.org...
>>>> Is it safe to soak a pcb in acetone for several minutes to clean it up
>>>> all
>>>> the flux? The board only has some QFN's, SMT LED's, and passive SMT's.
>>>> I
>>>> imagine the acetone won't harm these packages?
>>>
>>> I think acetone, MEK and similar solvents are too harsh. They can
>>> dissolve
>>> or swell some plastics and may damage components.
>>>
>>> I use 91% isopropyl alcohol or denatured ethanol both are mild and work
>>> well. Use a small brush to loosen flux then wipe with a soft clean
>>> cloth.
>>> Re-do if any residue remains.
>>>
>>
>>+1 on the alcohol recommendation. use an acid brush with the bristles cut
>>down to 1/2" long. squirt the alcohol inside the hollow brush handle and
>>it
>>will wick down the bristles while you are scrubbing.
>
> IPA tends to leave white residue when used to clean rosin flux.
>
>>Once the heavy buildup is loose, put paper towel between the board and the
>>brush and repeat allowing the papertowel to absorb the liquified flus and
>>alcohol mix.
>
> For really clean boards, the last step should be a squirt rinse with
> clean solvent.
>
> John


By alcohol I was referrring to 190 proof Everclear from the liquor store.
Seem I always have some handy for some reason. Keep the cap closed tight so
it doesn't absorb water.

I've never had a problem with white residue.





From: Mycelium on 17 Jan 2010 14:25
On Sun, 17 Jan 2010 10:06:12 -0600, "mook johnson" <mook(a)mook.net> wrote:

>
>"John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message
>news:mtp3l5tmtk8jg16b7bt4n7f88s281tou7s(a)4ax.com...
>> On Sat, 16 Jan 2010 07:12:35 -0600, "mook johnson" <mook(a)mook.net>
>> wrote:
>>
>>>
>>>"Bob Eld" <nsmontassoc(a)yahoo.com> wrote in message
>>>news:hipunq$h3h$1(a)news.eternal-september.org...
>>>>
>>>> "Jon Slaughter" <Jon_Slaughter(a)Hotmail.com> wrote in message
>>>> news:hipkai$h07$1(a)news.eternal-september.org...
>>>>> Is it safe to soak a pcb in acetone for several minutes to clean it up
>>>>> all
>>>>> the flux? The board only has some QFN's, SMT LED's, and passive SMT's.
>>>>> I
>>>>> imagine the acetone won't harm these packages?
>>>>
>>>> I think acetone, MEK and similar solvents are too harsh. They can
>>>> dissolve
>>>> or swell some plastics and may damage components.
>>>>
>>>> I use 91% isopropyl alcohol or denatured ethanol both are mild and work
>>>> well. Use a small brush to loosen flux then wipe with a soft clean
>>>> cloth.
>>>> Re-do if any residue remains.
>>>>
>>>
>>>+1 on the alcohol recommendation. use an acid brush with the bristles cut
>>>down to 1/2" long. squirt the alcohol inside the hollow brush handle and
>>>it
>>>will wick down the bristles while you are scrubbing.
>>
>> IPA tends to leave white residue when used to clean rosin flux.
>>
>>>Once the heavy buildup is loose, put paper towel between the board and the
>>>brush and repeat allowing the papertowel to absorb the liquified flus and
>>>alcohol mix.
>>
>> For really clean boards, the last step should be a squirt rinse with
>> clean solvent.
>>
>> John
>
>
>By alcohol I was referrring to 190 proof Everclear from the liquor store.
>Seem I always have some handy for some reason. Keep the cap closed tight so
>it doesn't absorb water.
>
>I've never had a problem with white residue.
>
>
>
>
Grain alcohol and isopropyl alcohol (IPA) are two entirely different
molecules. One is for drinking, and the other is the solvent, and is
used in labs.
From: mook johnson on 17 Jan 2010 20:39

"Mycelium" <mycelium(a)thematrixattheendofthemushroomstem.org> wrote in
message news:lto6l5thvn52rjd113r9ff5l6r1l1tf1np(a)4ax.com...
> On Sun, 17 Jan 2010 10:06:12 -0600, "mook johnson" <mook(a)mook.net> wrote:
>
>>
>>"John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in
>>message
>>news:mtp3l5tmtk8jg16b7bt4n7f88s281tou7s(a)4ax.com...
>>> On Sat, 16 Jan 2010 07:12:35 -0600, "mook johnson" <mook(a)mook.net>
>>> wrote:
>>>
>>>>
>>>>"Bob Eld" <nsmontassoc(a)yahoo.com> wrote in message
>>>>news:hipunq$h3h$1(a)news.eternal-september.org...
>>>>>
>>>>> "Jon Slaughter" <Jon_Slaughter(a)Hotmail.com> wrote in message
>>>>> news:hipkai$h07$1(a)news.eternal-september.org...
>>>>>> Is it safe to soak a pcb in acetone for several minutes to clean it
>>>>>> up
>>>>>> all
>>>>>> the flux? The board only has some QFN's, SMT LED's, and passive
>>>>>> SMT's.
>>>>>> I
>>>>>> imagine the acetone won't harm these packages?
>>>>>
>>>>> I think acetone, MEK and similar solvents are too harsh. They can
>>>>> dissolve
>>>>> or swell some plastics and may damage components.
>>>>>
>>>>> I use 91% isopropyl alcohol or denatured ethanol both are mild and
>>>>> work
>>>>> well. Use a small brush to loosen flux then wipe with a soft clean
>>>>> cloth.
>>>>> Re-do if any residue remains.
>>>>>
>>>>
>>>>+1 on the alcohol recommendation. use an acid brush with the bristles
>>>>cut
>>>>down to 1/2" long. squirt the alcohol inside the hollow brush handle
>>>>and
>>>>it
>>>>will wick down the bristles while you are scrubbing.
>>>
>>> IPA tends to leave white residue when used to clean rosin flux.
>>>
>>>>Once the heavy buildup is loose, put paper towel between the board and
>>>>the
>>>>brush and repeat allowing the papertowel to absorb the liquified flus
>>>>and
>>>>alcohol mix.
>>>
>>> For really clean boards, the last step should be a squirt rinse with
>>> clean solvent.
>>>
>>> John
>>
>>
>>By alcohol I was referrring to 190 proof Everclear from the liquor store.
>>Seem I always have some handy for some reason. Keep the cap closed tight
>>so
>>it doesn't absorb water.
>>
>>I've never had a problem with white residue.
>>
>>
>>
>>
> Grain alcohol and isopropyl alcohol (IPA) are two entirely different
> molecules. One is for drinking, and the other is the solvent, and is
> used in labs.


Grain Alcohol is indeed a good solvent. It is often used in wood finishing
to thin shellac.

Works great on flux too. and Flaming Dr Peppers. :)


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