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.