On Mon, 30 Jun 2008 02:35:05 +0100 (BST)
ard at p850ug1.demon.co.uk (Tony Duell) wrote:
Incidentally, I found some acetic acid (fairly
concentrated too), in
the 'Kosher' section of the local supermarket. I have no idea what
the intended application of it is, but it's quite useful for cleaning
up NiCd corrosion too.
Well. Actually acetic acid is the acid in vinegar. Most
Yes, I am well aware of that :-)
stuff is just pure acetic acid without any
Well, it's certainly not pure acetic acid, since it's a solution in water
:-). But yes, there's nothing else added.
Why you'd use that in Kosher food is something I don't know. But of
course it has other applications for the likes of us :-)
Remember: If you are going to dilute concentrated acid
the acid into water. Never do it the other way around. Pouring water
Indeed. This is particularly important with sulphuric acid, which reacts
quite violently with water. Adding water to concentracted sulphuric acid
is not something to try!
into concentrated acid may cause the water to heat up
quite quick. High
enough to make the water boil instantly. The result are drops of water
and concentrated acid jumping around. Preferably onto your skin and into
I don't think you meant 'preferably' here. I certianly would prefer it if
the acid did not end up in my face. But murphey's law says it will :-(
citric acid in the dark room because it doesn't smell.)
As a stop bath?
Yes. Actually I use the special photo stuff with ph-indicator. But simple
citric acid from the drug store does as well. It is much cheaper then
Right, I'll give that a go. All it needs to do, of course, is neutralise
(or slightly acidify) the alkali in the developer to stop the latter from
the photo stuff. Unfortunately I got this knowledge
after I had
purchased the photo stuff already.
I discovered many years ago that something sold for photographic use was
always a lot mroe expensive than the same thing sold for other purposes :-).
Coca Cola should work too as it contains phosphoric acid. (For
cleaning. I am surely not going to dip my fibre based photo paper in
Coke. ;-) )
It's also got a lot of sugar and other gunk in it, which I'd rather not
have all over my PCBs.