Sulphuric acid + Hydrogen Peroxide
Original message:
- Once the board is insolated and developed, place it on a plastic tray
- Pour hydrochloric acid at 25% conc., which you should be able to get easy
(at least here in Spain I can get 3-litre bottles for around $2), until it
covers the board.
- With a syringe, pour drop by drop some strong (30% by volume) hydrogen
peroxide (H2O2). You will see the exposed copper dissolve.
- Carefully, don't let bubbles form, if you see some appearing, just pour a
little water to stop them, keep going until all unwanted copper has
dissolved.
- Take the board, rinse it very well, and polish with some nail-varnish
remover to get the final copper finish.
Al's response:
Please be careful. If I'm not mistaken, the process you outline will release
Chlorine gas so you should be under a vent hood or at least in a very
well-ventilated area. This is always a good idea anyway.
Regards,
Al Williams
·
My response:
Al, I'm sure you're just covering all the bases, but....
Sulphuric acid (H2SO4) + Hydrogen Peroxide (H2O2) + copper can't produce
chlorine gas. I admit my chemistry may be a bit rusty, but there ain't no
chlorine there.
I freely admit there may be (poisonous) fumes of some type, but not of
chlorine.
However, let me point out a few things that may pour cold water <joke> on
the whole suggestion.
1. Suphuric acid is not something to fool with. Even at low concentrations it
can easily burn skin and spatter into eyes.
2. You cannot (safely) pour water into suphuric acid. Why not? Because the
water is lighter than the acid, and will "float" on top. Gradually, drops of water
fall into the acid, and·diring mixing, get hot, changing to steam, and throwing
drops of acid far and wide. Bad. Usually VERY bad.
3. A spill of sulphric acid is hard to clean up. It eats things away, and may
accidentally fall onto something that WILL give off poisonous fumes.
4. Finally, the nail-varnish remover is nothing more than acetone, and that's
another chemical to be very careful with. It's very flammable, and should not
be breathed.
All in all, the ferric chloride solution is pretty fool-proof, although it takes a
little time, and of course a heater is a big help. One thing to be careful of
(rarely mentioned) is that ferric chloride will stain (permanently) a lot of
things, like concrete, clothing, hands (well, maybe not permanently), and
lots of plastics.
Sorry to be so long. Hope this helps......JP Harrison
- Once the board is insolated and developed, place it on a plastic tray
- Pour hydrochloric acid at 25% conc., which you should be able to get easy
(at least here in Spain I can get 3-litre bottles for around $2), until it
covers the board.
- With a syringe, pour drop by drop some strong (30% by volume) hydrogen
peroxide (H2O2). You will see the exposed copper dissolve.
- Carefully, don't let bubbles form, if you see some appearing, just pour a
little water to stop them, keep going until all unwanted copper has
dissolved.
- Take the board, rinse it very well, and polish with some nail-varnish
remover to get the final copper finish.
Al's response:
Please be careful. If I'm not mistaken, the process you outline will release
Chlorine gas so you should be under a vent hood or at least in a very
well-ventilated area. This is always a good idea anyway.
Regards,
Al Williams
·
My response:
Al, I'm sure you're just covering all the bases, but....
Sulphuric acid (H2SO4) + Hydrogen Peroxide (H2O2) + copper can't produce
chlorine gas. I admit my chemistry may be a bit rusty, but there ain't no
chlorine there.
I freely admit there may be (poisonous) fumes of some type, but not of
chlorine.
However, let me point out a few things that may pour cold water <joke> on
the whole suggestion.
1. Suphuric acid is not something to fool with. Even at low concentrations it
can easily burn skin and spatter into eyes.
2. You cannot (safely) pour water into suphuric acid. Why not? Because the
water is lighter than the acid, and will "float" on top. Gradually, drops of water
fall into the acid, and·diring mixing, get hot, changing to steam, and throwing
drops of acid far and wide. Bad. Usually VERY bad.
3. A spill of sulphric acid is hard to clean up. It eats things away, and may
accidentally fall onto something that WILL give off poisonous fumes.
4. Finally, the nail-varnish remover is nothing more than acetone, and that's
another chemical to be very careful with. It's very flammable, and should not
be breathed.
All in all, the ferric chloride solution is pretty fool-proof, although it takes a
little time, and of course a heater is a big help. One thing to be careful of
(rarely mentioned) is that ferric chloride will stain (permanently) a lot of
things, like concrete, clothing, hands (well, maybe not permanently), and
lots of plastics.
Sorry to be so long. Hope this helps......JP Harrison
Comments
one on TV.
HCL + H2O2 + Cu
I didn't see any mention of H2SO4. Did I have a Senior Moment?
==
Alas the thirsty freshman
For that he is no more
For what he thought was H2O
Was H2SO4
===
Regards,
Al Williams
AWC
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