Homebrew_PCBs

Just made another double sided board with 10 mil traces. Quite a few
traces run between dip pins.

Anyway, I solder it all up, stick my DC ammeter on and power it up.
150mA on a board that should take 6mA. I went looking for shorts
with my trusty razor knife - couldn't see any but I did some
scraping in really close spots anyway.

Still 50mA... Spend two hours desoldering, inspecting and re-
soldering, check and still 30mA. What the heck is going on I say to
myself!

After another hour of farting around, I came to the conclusion that
my flux is conductive! Using a rosin flux remover pen and some paper
(to soak the sludge up) I cleaned out the tightest spots and down go
the mAs to 10. Ran out of my spray on cleaner and its sunday of
course, no electronics suppliers open around here.

Looking at my flux container, I relized I'd grabbed my plumbing flux
instead - Oatay #5. I never realized that plumbing flux was so much
different from electronics flux. Lesson learned!

Hi,
Plumbing is acid core and electronics is rosin core. Even if you
flush the board the traces might still be eaten away over time. My
friend work at Heathkit. Even thought the kits came with solder and a
warning people would manage to use acid core. After a month or so the
radio-TV etc would start doing crazy things.

John




--- In Homebrew_PCBs@yahoogroups.com, "ghidera2000"
<ghidera2000@y...> wrote:

> Just made another double sided board with 10 mil traces. Quite a

few

> traces run between dip pins.
>
> Anyway, I solder it all up, stick my DC ammeter on and power it up.
> 150mA on a board that should take 6mA. I went looking for shorts
> with my trusty razor knife - couldn't see any but I did some
> scraping in really close spots anyway.
>
> Still 50mA... Spend two hours desoldering, inspecting and re-
> soldering, check and still 30mA. What the heck is going on I say

to

> myself!
>
> After another hour of farting around, I came to the conclusion that
> my flux is conductive! Using a rosin flux remover pen and some

paper

> (to soak the sludge up) I cleaned out the tightest spots and down

go

> the mAs to 10. Ran out of my spray on cleaner and its sunday of
> course, no electronics suppliers open around here.
>
> Looking at my flux container, I relized I'd grabbed my plumbing

flux

> instead - Oatay #5. I never realized that plumbing flux was so much
> different from electronics flux. Lesson learned!

yep better start making another because most likely
the acid is mixed in with the solder on top of the
trace it will continue eating the trace and or pads
it is on i made this mistake once dispite my best
attemps to fix the problem with in a few months
i had to throw it out and do it again bye the way
it will also eat the legs and leeds of the parts
you put in the board in no time you will see green
salts around the pins good luck but sorry about the
board
--- crankorgan <john@...> wrote:

> Hi,
> Plumbing is acid core and electronics is rosin
> core. Even if you
> flush the board the traces might still be eaten away
> over time. My
> friend work at Heathkit. Even thought the kits came
> with solder and a
> warning people would manage to use acid core. After
> a month or so the
> radio-TV etc would start doing crazy things.
>
> John
>
>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, "ghidera2000"
> <ghidera2000@y...> wrote:
> > Just made another double sided board with 10 mil
> traces. Quite a
> few
> > traces run between dip pins.
> >
> > Anyway, I solder it all up, stick my DC ammeter on
> and power it up.
> > 150mA on a board that should take 6mA. I went
> looking for shorts
> > with my trusty razor knife - couldn't see any but
> I did some
> > scraping in really close spots anyway.
> >
> > Still 50mA... Spend two hours desoldering,
> inspecting and re-
> > soldering, check and still 30mA. What the heck is
> going on I say
> to
> > myself!
> >
> > After another hour of farting around, I came to
> the conclusion that
> > my flux is conductive! Using a rosin flux remover
> pen and some
> paper
> > (to soak the sludge up) I cleaned out the tightest
> spots and down
> go
> > the mAs to 10. Ran out of my spray on cleaner and
> its sunday of
> > course, no electronics suppliers open around here.
> >
> > Looking at my flux container, I relized I'd
> grabbed my plumbing
> flux
> > instead - Oatay #5. I never realized that plumbing
> flux was so much
> > different from electronics flux. Lesson learned!
>
>

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>From: "ghidera2000" <ghidera2000@...>
>Reply-To: Homebrew_PCBs@yahoogroups.com
>To: Homebrew_PCBs@yahoogroups.com
>Subject: [Homebrew_PCBs] Board status in flux
>Date: Sun, 24 Aug 2003 15:54:34 -0000
>
>Just made another double sided board with 10 mil traces. Quite a few
>traces run between dip pins.
>
>Anyway, I solder it all up, stick my DC ammeter on and power it up.
>150mA on a board that should take 6mA. I went looking for shorts
>with my trusty razor knife - couldn't see any but I did some
>scraping in really close spots anyway.
>
>Still 50mA... Spend two hours desoldering, inspecting and re-
>soldering, check and still 30mA. What the heck is going on I say to
>myself!
>
>After another hour of farting around, I came to the conclusion that
>my flux is conductive! Using a rosin flux remover pen and some paper
>(to soak the sludge up) I cleaned out the tightest spots and down go
>the mAs to 10. Ran out of my spray on cleaner and its sunday of
>course, no electronics suppliers open around here.
>
>Looking at my flux container, I relized I'd grabbed my plumbing flux
>instead - Oatay #5. I never realized that plumbing flux was so much
>different from electronics flux. Lesson learned!

I think plumbing flux contains zinc chloride, which is quite conductive.
You'd have had serious corrosion problems if you had left it on.

Leon
--
Leon Heller, G1HSM Tel: +44 1424 423947
Email:leon_heller@...
My web page: http://www.geocities.com/leon_heller

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Thankfully, this is a prototype board that I don't expect to have in
service very long. Probably no more than a few weeks to a month. I
have a couple more things to add to the circuit but I want to make
sure the part I have done actually functions as expected -
particularly battery life. With four AAAs in series I should be able
to get 30 days in low power mode - gonna see if the theory resembles
reality :D


--- In Homebrew_PCBs@yahoogroups.com, kenneth magers
<kenneth_m_73149@y...> wrote:

> yep better start making another because most likely
> the acid is mixed in with the solder on top of the
> trace it will continue eating the trace and or pads
> it is on i made this mistake once dispite my best
> attemps to fix the problem with in a few months
> i had to throw it out and do it again bye the way
> it will also eat the legs and leeds of the parts
> you put in the board in no time you will see green
> salts around the pins good luck but sorry about the
> board

Hello ghidera2000,

24. August 2003, 17:54:34, you wrote:

<snip>

g> Looking at my flux container, I relized I'd grabbed my plumbing flux
g> instead - Oatay #5. I never realized that plumbing flux was so much
g> different from electronics flux. Lesson learned!

And I replied:

As soon as possible tin plate all your copper on the finished board! 10mil
traces could be 'eaten' by the residue of the zinc chloride!

20 years ago I made an small board and after 2 to 3 months it had some
traces broken.

--
Best Regards,
Zoran
mailto:zasto@...
www.zas-elmed.co.yu