Prev: Good Contact Cleaner ?
Next: Jeff Liebermann Radio Ham Fuckwit
From: Wild_Bill on 6 Apr 2010 12:18
I have seen clear metal prep/phosphoric acid, but a colored product would
complicate testing, as others may find differently colored solutions.

The reason I didn't mention muriatic acid (swimming pool chemical, concrete
cleaner/etcher, and good for removing rust from steel) because the muriatic
I've seen has had a dark amber color.

--
WB
..........


"N_Cook" <diverse(a)tcp.co.uk> wrote in message
news:hpfm3t$lib$1(a)news.eternal-september.org...
> Wild_Bill <wb_wildbill(a)XSPAMyahoo.com> wrote in message
> news:nwzun.345696$Hq1.316805(a)en-nntp-04.dc1.easynews.com...
>> Citric acid should be widely available, and you might want to try
> phosphoric
>> acid if you can find a source for a small amount. Phosphoric acid is used
> in
>> foods, but also as a diluted solution to etch and clean metals before
>> applying paints or other corrosion-preventive coatings. Most autobody
>> repair/refinishing shops will be familiar with diluted phosphoric acid as
> a
>> preparatory step in applying primer to steel or aluminum (aluminium?)
> parts.
>> A typical generic term here in the US is "metal prep". A paint distribuor
>> should have a way to get diluted PA for you, but you may have to buy a
> quart
>> (1L sized bottle).
>>
>> Diluted PA isn't particularly dangerous to handle, but it stings if it
> gets
>> into a cut in the skin, avoid any conact with eyes.
>>
>> I don't know if either of these acids would be useful for detecting lead,
> or
>> lead-free solders.
>>
>> --
>> Cheers,
>> WB
>> .............
>>
>>
>
> The PA I found as rust remover (hardware and car spares shops) probably
> has
> dye/colour change stuff in it, so defeating the purpose here
>
>

From: Jeff Layman on 6 Apr 2010 14:02
"N_Cook" <diverse(a)tcp.co.uk> wrote in message
news:hpcviv$bl3$1(a)news.eternal-september.org...
> Just checked a day later and the SnPb boiled in vinegar for 20 seconds
> plus
> potassium iodide shows a slight yellow colour compared to the PbF sample.
> What other non-license source of a strong acid other than car battery
> acid?
> drain cleaner is clobbered by elfin safety these days.
>


Conc Sulphuric Acid (95%+) and Conc Hydrochloric Acid (35%) are available
from many sources (such as Robert Dyas). The H2SO4 is used for unblocking
drains. But even though boiling H2SO4 attacks lead, it forms the insoluble
sulphate which inhibits further action (and being insoluble, it is difficult
to test it for lead). Boiling HCl attacks lead, and forms the soluble
chloride, which would be ideal to test for lead. But I wonder how long it
would be before Elf'n'safety appeared when your neighbours start choking?...

I doubt the purity of either acid would help ascertain the Pb content of
solder. They may contain lead as an impurity anyway.

--

Jeff

From: Dave Platt on 6 Apr 2010 14:03
In article <g9Jun.138157$Bs1.19927(a)en-nntp-01.dc1.easynews.com>,
Wild_Bill <wb_wildbill(a)XSPAMyahoo.com> wrote:

>The reason I didn't mention muriatic acid (swimming pool chemical, concrete
>cleaner/etcher, and good for removing rust from steel) because the muriatic
>I've seen has had a dark amber color.

Hmmm... odd.

The quart of muriatic acid I bought at a local hardware store (to make
PC-board etchant) is water-clear. No color at all, until after I
etched... at which point the copper(II) chloride makes a lovely
blue-green.

--
Dave Platt <dplatt(a)radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
From: tm on 6 Apr 2010 21:22

"N_Cook" <diverse(a)tcp.co.uk> wrote in message
news:hpcviv$bl3$1(a)news.eternal-september.org...
> Just checked a day later and the SnPb boiled in vinegar for 20 seconds
> plus
> potassium iodide shows a slight yellow colour compared to the PbF sample.
> What other non-license source of a strong acid other than car battery
> acid?
> drain cleaner is clobbered by elfin safety these days.
>
>

Put some hydrogen peroxide in the HAc and it will go after the lead pronto.

Tom


From: N_Cook on 7 Apr 2010 05:04
Dave Platt <dplatt(a)radagast.org> wrote in message
news:pk9s87-6d4.ln1(a)radagast.org...
> In article <g9Jun.138157$Bs1.19927(a)en-nntp-01.dc1.easynews.com>,
> Wild_Bill <wb_wildbill(a)XSPAMyahoo.com> wrote:
>
> >The reason I didn't mention muriatic acid (swimming pool chemical,
concrete
> >cleaner/etcher, and good for removing rust from steel) because the
muriatic
> >I've seen has had a dark amber color.
>
> Hmmm... odd.
>
> The quart of muriatic acid I bought at a local hardware store (to make
> PC-board etchant) is water-clear. No color at all, until after I
> etched... at which point the copper(II) chloride makes a lovely
> blue-green.
>
> --
> Dave Platt <dplatt(a)radagast.org> AE6EO
> Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
> I do _not_ wish to receive unsolicited commercial email, and I will
> boycott any company which has the gall to send me such ads!


I tried repeating the leaded solder + vinegar heated and potassium iodide
and no yellow colour after a day.

Remembered I had some 10 yearold car-body treatment Loctite Rust Remedy in
the shed.
With SnPb solder shavings and water ,boiled up for 30 seconds turned to a
clear strong orange colour over a cloudy mass , if left to settle.
Boiling the loctite and water on its own remained cloudy cream colour
throughout, no settling out.
Sn/Ag/Cu gave a cloudy very slight yellow colour.
Tried some iron filings, as there is supposed to be a colour change to blue
for rust treatement, and the test tube sample went via grey-green to black.
Will try Cu and Zn filings and Sn filings and then repeat the set again to
see if there is consistency


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://diverse.4mg.com/index.htm



First  |  Prev  |  Next  |  Last
Pages: 1 2 3 4
Prev: Good Contact Cleaner ?
Next: Jeff Liebermann Radio Ham Fuckwit