Removing epoxy resin from a PCB
Dave Plowman (News)
a fault on the PCB. Which is potted in what looks like epoxy resin on the
component side.
I'd normally just buy a new one - but have trillions of staples for it
bought off Ebay.;-)
I can get a new PCB for approx 60 gbp - but that's more than the thing
cost new.
Any ideas about removing the potting compound hopefully without damaging
the identification on the components? I've likely got everything on that
board 'in stock' so would be happy to replace the lot. But don't have a
schematic.
--
*I used up all my sick days so I called in dead
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Ross Herbert
wrote:
: I've got a B&D stapler which has died. The solenoid is ok, so it's likely
:a fault on the PCB. Which is potted in what looks like epoxy resin on the
:component side.
:
: I'd normally just buy a new one - but have trillions of staples for it
:bought off Ebay.;-)
:
: I can get a new PCB for approx 60 gbp - but that's more than the thing
:cost new.
:
: Any ideas about removing the potting compound hopefully without damaging
:the identification on the components? I've likely got everything on that
:board 'in stock' so would be happy to replace the lot. But don't have a
:schematic.
I would forget about trying to dissolve the epoxy. While this can be achieved
the chemicals required will cost as much as the new pcb and they will attack the
components as well as the epoxy. Many years ago I tried it with an epoxy potted
ignition system from a Johnson outboard motor and it took weeks to dissolve the
epoxy and all the component colour codes were taken off as well. Some components
also had their epoxy/plastic coatings removed as well. Surely you can still buy
a stapler which will use the staples you have in stock?
N_Cook
news:5052c6e...@davenoise.co.uk...
I did find once on an epoxy covered VCR daughter board that the epoxy may
have lifted some IC pins via differential thermal expansion or something.
Externally forced the package back with cable ties , wedges and rubber IIRC.
Didn't attempt trying to remove the epoxy.
Did once manage to excavate with a Dremmel and fine grinder but forget what
that was over, probably not labelled ICs. If you're lucky they will have
diluted the epoxy with carbonate filler so not so hard going
--
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bz
> I've got a B&D stapler which has died. The solenoid is ok, so it's
> likely
> a fault on the PCB. Which is potted in what looks like epoxy resin on
> the component side.
>
> I'd normally just buy a new one - but have trillions of staples for it
> bought off Ebay.;-)
>
> I can get a new PCB for approx 60 gbp - but that's more than the thing
> cost new.
>
> Any ideas about removing the potting compound hopefully without
> damaging
> the identification on the components? I've likely got everything on that
> board 'in stock' so would be happy to replace the lot. But don't have a
> schematic.
>
We used to boil epoxy coated capacitors in DMF (di methyl formamide)
[nasty stuff! Avoid contact, breathing etc.] It WILL take off the epoxy
but it will also corrode metals.
--
bz 73 de N5BZ k
please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.
bz+...@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
Lordoftenbroke
drink) and it seemed to work somewhat, god knows what it does to your
insides !
HTH.
"Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
news:5052c6e...@davenoise.co.uk...
N_Cook
news:0CNJl.21073$OO7....@text.news.virginmedia.com...
> This may sound stupid, but a place I used to work tried coke (the fizzy
> drink) and it seemed to work somewhat, god knows what it does to your
> insides !
>
> HTH.
>
I will give that a try. Do you warm up the liquid ? keep it all at an
elevated temperature for hours ? scrape with a blade after soaking? prize
under with a blade?
N_Cook
I just tried a number of household chemicals in test cells with flakes of 2
week old cured epoxy, over a couple of hours, all at room temperature. The
test piece in coca cola is still hard. The only ones showing promise are
acetone as nail varnish remover and 2 types of paint stripper paste Polycell
with Dichloromethane and methanol and an "151" containing Methelene Chloride
and methanol, probably the same activce chemicals. Acetone and paint
stripper mixture look most promising producing a gooey mess and reduced soft
test piece in less than an hour. All with no mechanical action at all.
For pcb use I would recommend repeated sequence, motorised wire brush then
this mixture on the track side.
On the component side Dremmel and very small ballmill or burr to grind
around obvious faces to iCs, large caps, and transistors so you could prize
off the section of epoxy over any markings, then mixture of Dremmel or brush
and epoxy softener. Sustained elevated temperature may help the chemical
process.
alchazz
> Lordoftenbroke <Lordoft...@blueyonder.co.uk> wrote in message
> news:0CNJl.21073$OO7....@text.news.virginmedia.com...
>> This may sound stupid, but a place I used to work tried coke (the fizzy
>> drink) and it seemed to work somewhat, god knows what it does to your
>> insides !
>>
>> HTH.
>>
>>
>
> I will give that a try. Do you warm up the liquid ? keep it all at an
> elevated temperature for hours ? scrape with a blade after soaking?
> prize under with a blade?
Unless you are very careful, your epoxy solvent will destroy your PCB
also.
Al
Andy Cuffe
<da...@davenoise.co.uk> wrote:
> I've got a B&D stapler which has died. The solenoid is ok, so it's likely
>a fault on the PCB. Which is potted in what looks like epoxy resin on the
>component side.
>
> I'd normally just buy a new one - but have trillions of staples for it
>bought off Ebay.;-)
>
> I can get a new PCB for approx 60 gbp - but that's more than the thing
>cost new.
>
> Any ideas about removing the potting compound hopefully without damaging
>the identification on the components? I've likely got everything on that
>board 'in stock' so would be happy to replace the lot. But don't have a
>schematic.
Use a heat gun set to a temperature below the melting point of solder.
Epoxy gets much softer and weaker as it heats up. At the right
temperature, it will scrape off like putty.
Andy Cuffe
N_Cook
--
--
N_Cook <div...@tcp.co.uk> wrote in message
news:gt9ebn$ddq$1...@news.eternal-september.org...
I tried mix of paint stripper about 1 : to nail varnish remover about 5:
coke cola about 5 and my test bit of epoxy disappeared to gloop in about 3
hours, the stripper + acetone test epoxy one is still substantially there -
weird
Sam Goldwasser
I haven't tried it, but I know someone who supposedly used a propane
torch to soften up the Epoxy and then scraped it off. This was a potted
laser power supply brick and the resulting PCB looks like new.
--
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N_Cook
news:aisgv4ll2l5f9r3bg...@4ax.com...
But the solder is still connected to active components and now surrounded in
a large thermal mass, not the quick jab and scarper of the soldering
operation
For a populated board , how high a temp would you allow the epoxy and hence
thermal mass of enclosed active componentry to get up to?
I think I would bury a diode in there and monitor the forward voltage for
temp guide.
I'de be happy with 70 degree C and probably 100 deg C , but how much higher
?
James Yuan
For more visit:
https://www.epoxyadhesiveglue.com/
https://www.deepmaterialcn.com/