home and hobby chemicals licensing

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Peter Fairbrother

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Jan 26, 2022, 8:00:51 AMJan 26
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The UK Government is proposing to limit the concentration of acids and
some other chemicals which home users with licenses can possess to the
following:

Hydrogen Peroxide 35%
Nitric acid 10%
Sulfuric acid 40%
Chlorates and perchlorates 40%
Ammonium nitrate 16%N

Note this is with a license, without a license the concentrations are lower.

Having to get a license is one thing, but making licenses unavailable is
quite another. I am going to reply to the consultation, and so - does
anybody know of any legitimate hobby/home uses for any of these
chemicals at high concentration?

- Hydrogen peroxide at >35% is mostly the province of rocket fuel,
though 50% is used in some home chip-making techniques (yes, people do
make microchips at home - record so far is 1,200 transistors afaik).


- There are quite a few uses for strong nitric acid at above 10%:
50% passivating stainless
50% iron particle removal from machined nickel alloy parts safety critical
50%+ precious metal recovery and refining
50% unknown metal testing
70% gold test kits
86%+ (fuming) decapping microchips


- The only use I have come up with so far that needs >40% sulphuric is
for making acid pirhana solution for cleaning glass and ceramics. The
commercial 98% is undoubtedly useful for topping up baths for anodising,
electroplating and electroforming, but it could be argued that 40% is
sufficient here - not sure that is always true though, if you get in a
mess sometimes 98% is the only thing which will do.


- Chlorates and perchlorates at >40%. Chlorates were used as
weedkillers until the EU banned them on the grounds that nobody had
shown them to be safe for the environment (nobody had showed them to be
particularly dangerous either, and quite a few gardeners still swear by
sodium chlorate), but this may have actually been a reaction to the
sugar/chlorate explosive of boys pranks and more dangerous uses.

They are also used in theatrical flash mixtures and for photography.

Plus a lot of fireworks components like stars will have >40% perchlorate.


- Ammonium nitrate at >16%N ??

Peter Fairbrother

RustyHinge

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Jan 26, 2022, 3:04:04 PMJan 26
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On 26/01/2022 13:00, Peter Fairbrother wrote:

>  - The only use I have come up with so far that needs >40% sulphuric is
> for making acid pirhana solution for cleaning glass and ceramics. The
> commercial 98% is undoubtedly useful for topping up baths for anodising,
> electroplating and electroforming, but it could be argued that 40% is
> sufficient here - not sure that is always true though, if you get in a
> mess sometimes 98% is the only thing which will do.

98%? Pooh! I would use oleum for making sulpho vanillin, a chemical used
for the identification of certain fungi.

When I was a yoof I could go into a chemist (not a pharmacist...) and
unless it was on the poisons tregister or some no-no like that, buy
anything over the counter, no questions asked. I often did too.

Now, the meddling killjoys have virtually removed from availability once
everyday compounds like potassium dichromate which I used to use for
artificially ageing some hardwoods.

"Why not use stain, sir?"

Because, you ignorant meddlesome control freak, when a wood like
mahogany or oak darkens with age, it's the harder, winter growth which
shows more oxidation, not the softer summer growth: a mirror-image of
staining, where the softer more porous open grain takes up stain more
readily. A dead give-away if you're restoring anything.

You can mix potassium dichromate with something combustible and it will
explode if you confine it and ignite it, but the expense! (When you can
cheaply buy huge bags of fertiliser you can detonate rather than
ignite...) Who the hell is going to bother with chromate, nitrate, &c?

--
Rusty Hinge
To err is human. To really foul things up requires a computer and the BOFH.

Peter Fairbrother

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Jan 26, 2022, 3:14:16 PMJan 26
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RustyHinge

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Jan 26, 2022, 5:01:38 PMJan 26
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Thanks for that - I hadn't done an online search 'cos the last thing I
wanted to oxydise must have been ten years ago when I was forging
Damascus steel knife blades and I was making a sgian dubh, which
traditionally has a black bog oak grip: I found a piece of the genuine
stuff in a Norwich outlet, so I used that.

But should I live long enough (I'm 81, you know. Where's that nurse?) I
shall have bought enough from J. Penney to treat an hundredweight or two.
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