Part 1 a couple of weeks back , using low temperature set soldering iron.

Have tried chemically using both potassium chromate and potassium iodide but
cannot make either work with elemental/eutectic lead. Not having a source of
conc nitric acid and colour of tin iodide being orange and tin chromate
being brown, so not that different to the yellow lead salts, may not have
worked anyway. I gave up along those lines after trying boiling up with
acetic acid and separately washing soda failed.

2 more physical tests.
Grey mark on paper.
Scrape back surface of the solder and rub a specific number of times with
some copier paper over a cocktail stick. Leaded solder leaves a much darker
grey mark, nearer black, on the paper.

Indentation test shows promise.
The following using a well worn automatic centre punch, so a new sharper one
for use only on soft metals is probably called for. This one, existing
spring replaced with a lighter one giving a load before trigger of 3.5Kg.
Comparing block of copper,Al, roofing lead and off the roll solder
wire,63/37 and 85.5/4/.5 silver solder laid over the lead as a soft anvil.
Steel rule with 1/100 inch markings and a x30 basic microscope
Measuring diameters of the indentations (x10 thou/mil)
Cu 1.5
Al 2.5
high tin solder 3
SnPb 4
Pb 5


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

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.

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
..............



"N_Cook" wrote in message
...
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.

Wild_Bill wrote in message
...
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
.............



"N_Cook" wrote in message
...
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.





2 days on and a more definite but pale yellow colouration , after shaking,
so a precipitate. Tin heavy sample still clear liquid. Perhaps it is just
picking up lead carbonate or something as contaminant on the surface, but
old SnPb is likely to be the only such to be found in the UK these days.
Will try boiling for 10 minutes in vinegar , i doubt you can grind down
solder in a mortar and pestle (another test maybe, perhaps high tin solder
will so grind down and not leaded version).

Will try getting phosphoric acid . Isn't there formic acid for de-calcifying
or something ?
The problem trying to get around is not post 2006 boards with PbF on the
overlay and green stickers on the casing but identifying boards like Yamaha
from 2001 or Marshall from 2003 but with PbF soldering


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

Wild_Bill wrote in message
...
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
.............



"N_Cook" wrote in message
...
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.




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

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" wrote in message
...
Wild_Bill wrote in message
...
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

"N_Cook" wrote in message
...
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

In article ,
Wild_Bill 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 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!

"N_Cook" wrote in message
...
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

Dave Platt wrote in message
news
In article ,
Wild_Bill 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 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

Given up on chemical tests , no consistency/ lack of differentiation.
Mortar and pestle idea goes no where.

Had to decide this week whether a 2003 board had failed solder due to SnPb
or PbF and excess heat , where it was used. Could not decide by appearance,
good mirror finish, lack of pastiness but solder joints too shallow to tell
domed from conical, so probably SnPb.
Low temp soldering iron test, melted - SnPb
Paper test - SnPb
and indentation test much nearer Pb diameter than Al so - SnPb

N_Cook wrote:
Part 1 a couple of weeks back , using low temperature set soldering iron.

Have tried chemically using both potassium chromate and potassium iodide but
cannot make either work with elemental/eutectic lead. Not having a source of
conc nitric acid and colour of tin iodide being orange and tin chromate
being brown, so not that different to the yellow lead salts, may not have
worked anyway. I gave up along those lines after trying boiling up with
acetic acid and separately washing soda failed.

2 more physical tests.
Grey mark on paper.
Scrape back surface of the solder and rub a specific number of times with
some copier paper over a cocktail stick. Leaded solder leaves a much darker
grey mark, nearer black, on the paper.

Indentation test shows promise.
The following using a well worn automatic centre punch, so a new sharper one
for use only on soft metals is probably called for. This one, existing
spring replaced with a lighter one giving a load before trigger of 3.5Kg.
Comparing block of copper,Al, roofing lead and off the roll solder
wire,63/37 and 85.5/4/.5 silver solder laid over the lead as a soft anvil.
Steel rule with 1/100 inch markings and a x30 basic microscope
Measuring diameters of the indentations (x10 thou/mil)
Cu 1.5
Al 2.5
high tin solder 3
SnPb 4
Pb 5


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



You need this, expensive though, or find out whats in the tester chemicals.

http://www.amazon.com/Homax-5250-Hou.../dp/B000E3DX0C

JC

Archon wrote:
N_Cook wrote:
Part 1 a couple of weeks back , using low temperature set soldering iron.

Have tried chemically using both potassium chromate and potassium
iodide but
cannot make either work with elemental/eutectic lead. Not having a
source of
conc nitric acid and colour of tin iodide being orange and tin chromate
being brown, so not that different to the yellow lead salts, may not have
worked anyway. I gave up along those lines after trying boiling up with
acetic acid and separately washing soda failed.

2 more physical tests.
Grey mark on paper.
Scrape back surface of the solder and rub a specific number of times with
some copier paper over a cocktail stick. Leaded solder leaves a much
darker
grey mark, nearer black, on the paper.

Indentation test shows promise.
The following using a well worn automatic centre punch, so a new
sharper one
for use only on soft metals is probably called for. This one, existing
spring replaced with a lighter one giving a load before trigger of 3.5Kg.
Comparing block of copper,Al, roofing lead and off the roll solder
wire,63/37 and 85.5/4/.5 silver solder laid over the lead as a soft
anvil.
Steel rule with 1/100 inch markings and a x30 basic microscope
Measuring diameters of the indentations (x10 thou/mil)
Cu 1.5
Al 2.5
high tin solder 3
SnPb 4
Pb 5


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



You need this, expensive though, or find out whats in the tester chemicals.

http://www.amazon.com/Homax-5250-Hou.../dp/B000E3DX0C

JC
or this
http://www.ojp.usdoj.gov/nij/trainin...2_t05_03_j.htm

Got some spirit of salts (32 percent hydrochloric acid) from a traditional
hardware shop. No colour reaction found heated with leaded solder and then
KI.
Also got a pot of sulphur and may try excessive heating as there seems to be
some sort of test that way producing a black lead sulphide colour.

I increased sample sizes to about 3cc of 32% HCl and about 30 cu-mm of
solder wire. About 1/3 of the wire scraped into scrapings and remainder
added as round and the part round remnant . After boiling and cooling twice
then perhaps about 5 to 10 cu-mm of KI added and repeated boiling and
cooling. For the leaded one bright orange crystals? soon appear on forced
cooling and flecks of glistening gold colour the second time of heating
cooling after KI . The glistening gold agrees with my chemistry book for
lead testing with KI, don't know about the orange. The colours and crystals
disappear on boiling.

The lead free one , no colours at all in the liquid but the metal goes
black. With repeated boiling then still a lot of gas comes off the metal for
some time after removing from the heat , unlike the leaded sample. Maybe
acting on the 5 percent silver content.


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

The KI came from a kids chemistry set in a charity shop. One way around kids
and chemistry and product liability, absolutely no name. Nothing on the box
and nothing in the accompanying book for makers name or even country of
origin.

Looks as though regular flicking of the test tube is important.
Repeated samples and again nothing appearing in the non-lead sample. The odd
flecks that would appear when shaken were probably reduced flakes of the
original scrapings, again black colour. Looks as though 30 cu-mm is about
the right amount of KI with 30 cu-mm of solder and initially 3cc of HCl. I
can only estimate using a small spatula that is in fact a stainless steel
lobster pick, fork+spoon. The 4mm wide spoon end is ideal for this. No
orange colour this time (initially) . Once a very slight yellow tinge to the
liquid appears and at boiling and through cooling , much flicking of the
tube with a finger, then instead of flecks that look like golden flakes of
skin you get a dense mass of more like cream-coloured soap flakes. Reheat
and all this dissolves well before boiling point. Allow to cool untouched
and then just a small scattering of fine gold-coloured flecks when you flick
the tube. The orange colour seems to only appear after repeated heating and
cooling, the second SnPb sample is now starting to show this orange colour
after 5 or 6 heat/cooling cycles.
The colour of the residual bits of SnPb solder masked by the
crystals/precipitate , but not obviously black.

followup
Looks as though the orange colouration is due to tin/stannic iodide, from
the Sn in SnPb and PbF. After a week or so the orange colouration appeared
in the solution in the PbF test tube also.
Even more convincing collection of scintillating gold flecks in the SnPb
test tubes