Hi all,

I want to do some anodising, and I am trying to locate a source of
sulphuric acid. Battery acid would probably be the easiest way to get
hold of it, but all the car part places around me say that they aren't
allowed to stock it any more because it is a restricted substance.
Curiously, despite being restricted, I can still buy it mail order and
have it sent to me through the post (http://www.getgeared.co.uk/
acatalog/Battery_Acid_1_Litre.html)!

If I can I want to avoid the postage charge for mail order (the cost
of the acid is less than the P+P) so does anyone know of any other
place that would stock sulphuric acid?

thanks,

dan.

wrote in message
...
Hi all,

I want to do some anodising, and I am trying to locate a source of
sulphuric acid. Battery acid would probably be the easiest way to get
hold of it, but all the car part places around me say that they aren't
allowed to stock it any more because it is a restricted substance.
Curiously, despite being restricted, I can still buy it mail order and
have it sent to me through the post (http://www.getgeared.co.uk/
acatalog/Battery_Acid_1_Litre.html)!

If I can I want to avoid the postage charge for mail order (the cost
of the acid is less than the P+P) so does anyone know of any other
place that would stock sulphuric acid?

thanks,

dan.

A plating works, I should think. My next door neighbour is involved with
one, and they have it. They also do anodising, and have all sorts of people
coming in off the street to have little jobs done, and often, they are able
to chuck it in with a commercial job, so payment is a few quid for the tea
money jar. If you have such a works anywhere nearby, might be worth you
giving them a bell, just to ask ... ??

Arfa

wrote in message
...
Hi all,

I want to do some anodising, and I am trying to locate a source of
sulphuric acid. Battery acid would probably be the easiest way to get
hold of it, but all the car part places around me say that they aren't
allowed to stock it any more because it is a restricted substance.
Curiously, despite being restricted, I can still buy it mail order and
have it sent to me through the post (http://www.getgeared.co.uk/
acatalog/Battery_Acid_1_Litre.html)!

If I can I want to avoid the postage charge for mail order (the cost
of the acid is less than the P+P) so does anyone know of any other
place that would stock sulphuric acid?


You could try any big builders merchants and look at drain cleaners. Some
are sulphuric acid others sodium hydroxide.

Anodising is fiddly. Unless you really want to d-i-y or you have a lot to
do or an odd colour it may be worth just asking a local anodiser. I had all
the parts for a microscope black anodised by a local works for £10 - less
than it would have cost me to set up and do it myself.

On 16 Jul, 09:24, wrote:

I want to do some anodising, and I am trying to locate a source of
sulphuric acid.

Liquid drain cleaner. The acidic ones for unblocking drains are conc.
(96%) sulphuric. Just check that it's not either alkaline / basic
sodium hydroxide, and that it's not a limescale shifter based on
sulphamic or formic acids. Mine (for electroplating) costs me about
£6 / litre and is available from the local hardware shop. It's not
hard to find.

Aluminium is a faff to anodise and you might prefer to start with
titanium, which is _far_ easier. Use Pepsi as an electrolyte and a
variac (with rectification), or else a variable bench PSU that goes to
fairly high output voltages.

Thanks for your replies. I'll try the drain cleaner approach.

The closest anodising firm to me is about 15 miles away, and the one
time I did go to them they made a mess of one of my parts, and lost
another, so I'm not going back there. And yes, titanium may be easier
to anodise, but not to machine in the first place!

thanks,

dan.

"Andy Dingley" wrote in message
...
On 16 Jul, 09:24, wrote:

I want to do some anodising, and I am trying to locate a source of
sulphuric acid.

Liquid drain cleaner. The acidic ones for unblocking drains are conc.
(96%) sulphuric. Just check that it's not either alkaline / basic
sodium hydroxide, and that it's not a limescale shifter based on
sulphamic or formic acids. Mine (for electroplating) costs me about
£6 / litre and is available from the local hardware shop. It's not
hard to find.

Aluminium is a faff to anodise and you might prefer to start with
titanium, which is _far_ easier. Use Pepsi as an electrolyte and a
variac (with rectification), or else a variable bench PSU that goes to
fairly high output voltages.

A bit vague on the details as it was some years ago that I used to maintain
the baths on an anodising plant, but you may find that it is the current
that defeats you. You have to have the requisite amount of amps per square
metre of surface to be anodised. At home, I could only manage pieces up to
a few inches with the battery chargers I had to hand. In our baths we had
aluminium girder bus bars that typically took 1500 amp at 12-15 volt. Quite
spectacular when one day I happened to drop an aluminium step ladder across
them!

Also, you might note that the new coating has to be sealed - typically by
boiling in water to make the oxide swell and become less porous. It is this
swelling that seals in the various colours you see in saucepan lids for
example - the dye being added to the sealing water bath. (We also sealed
our printing plates with a chemical solution, but it was nasty stuff, so
boiling water is your best bet. That said, I did some of my motorcycle
parts boiling in candle wax, and they came out quite nice too.) The water
has to be very clean (distilled or deionised) or the coating gets
stained/smeared.

Another thing you should note, is that the colour you get depends on the
alloy. Most 'aluminium' is actually an alloy with magnesium 'Magalloy' (has
a pinkish/bluish tinge), but there is an enormous range of alloys for
different applications. These in turn have different sized crystals
depending on how they were made and heat treated or cast. The anodising
current picks out all the imperfections and crystal boundaries, and the
different alloying metals make oxides of varying colours. Result is, you
never know quite what you are going to get. Sometimes you get a lovely
pattern of big crystals: sometimes you get black (my bike bits came out a
nice stony green/black).

Also, the existing oxide on the metal is best removed first - which we did
by dipping in well agitated caustic soda solution.

Thus there are lots of ways for this to go 'wrong', but all of them produce
interesting results. Just perhaps not what you are after!

S

wrote:
Hi all,

I want to do some anodising, and I am trying to locate a source of
sulphuric acid. Battery acid would probably be the easiest way to get
hold of it, but all the car part places around me say that they aren't
allowed to stock it any more because it is a restricted substance.
Curiously, despite being restricted, I can still buy it mail order and
have it sent to me through the post (http://www.getgeared.co.uk/
acatalog/Battery_Acid_1_Litre.html)!

If I can I want to avoid the postage charge for mail order (the cost
of the acid is less than the P+P) so does anyone know of any other
place that would stock sulphuric acid?

thanks,

dan.

Hundreds of old car batteries in scrapyards, just take a washing up bowl,
some strong rubber gloves and a bottle and funnel.

In article ,
Phil L wrote:
Hundreds of old car batteries in scrapyards, just take a washing up
bowl, some strong rubber gloves and a bottle and funnel.

I *think* they have to be emptied these days - not just left lying around
full of acid. Same as other fluids in a car.

--
*What boots up must come down *

Dave Plowman London SW
To e-mail, change noise into sound.

wrote:

Hi all,

I want to do some anodising, and I am trying to locate a source of
sulphuric acid. Battery acid would probably be the easiest way to get
hold of it, but all the car part places around me say that they aren't
allowed to stock it any more because it is a restricted substance.
Curiously, despite being restricted, I can still buy it mail order and
have it sent to me through the post (http://www.getgeared.co.uk/
acatalog/Battery_Acid_1_Litre.html)!

If I can I want to avoid the postage charge for mail order (the cost
of the acid is less than the P+P) so does anyone know of any other
place that would stock sulphuric acid?

I think that's what the farmers up here use it to spray the potato haulms,
to kill them off. D'you know any farmers? Farm supply companies
might be an alternative.

--
AnneJ

"Phil L" wrote in message
om...
wrote:
Hi all,

I want to do some anodising, and I am trying to locate a source of
sulphuric acid. Battery acid would probably be the easiest way to get
hold of it, but all the car part places around me say that they aren't
allowed to stock it any more because it is a restricted substance.
Curiously, despite being restricted, I can still buy it mail order and
have it sent to me through the post (http://www.getgeared.co.uk/
acatalog/Battery_Acid_1_Litre.html)!

If I can I want to avoid the postage charge for mail order (the cost
of the acid is less than the P+P) so does anyone know of any other
place that would stock sulphuric acid?

thanks,

dan.

Hundreds of old car batteries in scrapyards, just take a washing up bowl,
some strong rubber gloves and a bottle and funnel.


Trouble is, it's not sulphuric acid but a solution of that and lead
sulphate. Don't know how the lead would affect the anodising process, but
it would make disposal of the used experimental solutions a problematical
issue that you don't want to get into.

S

(PS appols for the confusing joining of Andy Dingley's comment and my added
remark in the other thread branch. Don't know how I managed that!)