Pickle

[not done it yetParticipant @notdoneityet]

Russell,

Sorry, but you were not too ( no, ‘not absolutely&rsquo clear, referring to concentrated sulphuric acid and 5% in the same paragraph.

Someone reading that may not understand that there are differences between the former and latter. As I said – not quite!

Yes, I’ve washed my hands in dilute hydrochloric acid before now (rinsed off, afterwards), but some may have far more sensitive skin than I had back in those days. I also know that sulphuric acid is non-volatile and will concentrate somewhat from a dilute solution, as the water evaporates. So after rinsing in water any splashed clothes really need an alkaline rinse is required to avoid holes in those clothes, later.

Directions for use of chemicals needs to be clear and totally unambiguoius. Having dispensed hundreds of 50 litre carboys of acids and alkalis into reaction vessels, I know not to mix concentrated and dilute warnings in the same paragragh, as you did. I’ve seen the effects of chemical mishaps, and prevented a few, in my lifetime.

I hope that is clear.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by not done it yet on 22/07/2018 11:48:05:

Russell,

Sorry, but you were not too ( no, ‘not absolutely&rsquo clear, referring to concentrated sulphuric acid and 5% in the same paragraph.

Someone reading that may not understand that there are differences between the former and latter. As I said – not quite!

[ … ]

I hope that is clear.

.

What on earth are those pesky 'auto-smiley' things up to now ?

MichaelG.

[Peter BuxtonParticipant @peterbuxton35723]

Hi guys, I have been doing jewellery for many years, I am not sure what metals you require the pickle for, but for silver the safest by a country mile is aluminium sulfate. 90% of all jewellers use it nowadays.

It is sold as "Safe jewellers pickle" and because they fail to leave out the msds, they charge far more than it is worth, but it is nothing more than aluminium sulphate. I am sure it will work on copper/brass and bronzes to.

I hope this helps someone,

Pete

[BazyleParticipant @bazyle]

the safest by a country mile is aluminium sulfate.

residents of Camelford might not agree with that.

[John RutzenParticipant @johnrutzen76569]

Hi thanks, aluminium sulphate seems easy to get and safe but what concentration do you need. I notice the stuff on eBay says it's 17%.

[Keith HaleParticipant @keithhale68713]

Repeat

10 gms of citric acid salt per litre of water.

Check it out at the local wine shop or supermarket or eBay or welding distributor!

Yes I’m sure.

Keith

[Phil H1Participant @philh196021]

A question for the chemists please;

I have about a 2 1/2 litre bottle of 95% sulphuric acid that is about 30 years old and I have noted the new laws to come into force in November.

I can very carefully dispose of the contents by heavy dilution etc but does anybody know how to safely dispose of the bottle that will now have traces of the acid inside. There are warnings about adding water to the acid if I was to rinse it out. Can any of the chemists out there explain how to do it please?

Phil H

[pgk pgkParticipant @pgkpgk17461]

I also have both part used and unused sulphuric about. Should I need to dispose of it then dilution and subsequent neutralisation is the way to go (as in add something like chalk). As for the bottle… lower it into a bucket of water with sensible care; mouth of jar away from you and decent washing up gloves/glasses.

pgk

[Martin KyteParticipant @martinkyte99762]

Posted by Phil H1 on 23/07/2018 11:02:00:

A question for the chemists please;

I have about a 2 1/2 litre bottle of 95% sulphuric acid that is about 30 years old and I have noted the new laws to come into force in November.

I can very carefully dispose of the contents by heavy dilution etc but does anybody know how to safely dispose of the bottle that will now have traces of the acid inside. There are warnings about adding water to the acid if I was to rinse it out. Can any of the chemists out there explain how to do it please?

Phil H

The hazard of adding water to concentrated acid is if you get a splash it's an concentrated acid splash. This doesn't really apply if you are rinsing out a bottle where the acid is very much less than the water you are pouring in.

regards Martin

[Ian S CParticipant @iansc]

There is a danger with dilute sulphuric acid. if it is splashed on a surface the water tends to evaporated leaving concentrated acid. Watch how you hold lead acid batteries, I remember that if held against my overalls, the front of them got eaten away in a fairly short time. The supposedly "spill proof" batteries that we used in aircraft weren't.

Ian S C

[Phil H1Participant @philh196021]

OK, thanks guys I will do that and I also have some home brew citric. I might do a comparison test (sulphuric vs citric) with some dirty copper to see how it goes. I suppose the very least I could do is to make an acid bath (below 15% sulphuric) before disposing of the sulphuric bottle.

Phil H

[SillyOldDufferModerator @sillyoldduffer]

Posted by Phil H1 on 23/07/2018 13:20:59:

OK, thanks guys I will do that and I also have some home brew citric. I might do a comparison test (sulphuric vs citric) with some dirty copper to see how it goes. I suppose the very least I could do is to make an acid bath (below 15% sulphuric) before disposing of the sulphuric bottle.

Phil H

No need to test it Phil, Sulphuric Acid out-performs (ie works faster) than Citric Acid, even hot Citric Acid.

The ideal pickle is cheap, reacts quickly with oxides, and doesn't produce toxic waste, or leave an insoluble mess on the item being cleaned. Dilute Sulphuric Acid, if you can get it, is good stuff. Industry use it in large quantities because Sulphuric Acid is fast, cheap, easy to clean off, and the waste is manageable. If you're lucky enough to own some sulphuric acid, why not buy some bigger plastic containers and dilute what you have down to pickling strength, store it somewhere safe, and use that?

Hydrochloric Acid isn't ideal as a pickle because it breaks the 'easy to clean off' rule. Unlike Sulphuric Acid which has an affinity for water and is straightforward to rinse, Hydrochloric leaves difficult to remove chloride ions inside the metal's pores creating corrosion sites. After a few years any surface protection is punctured from underneath allowing water and air to get in and finish the job.

I think I understand why Aluminium Sulphate would clean Silver, but not why it might be good for steel. Anyone tried it?

Dave

[Phil H1Participant @philh196021]

Thanks Dave, I am beginning to think that way. When I had a go at a boiler many years ago, I had an old, plastic paint type container safely under a very robust bench. It could take half a boiler length in one dip and lasted for ages. And you are right – I could store a large container down the side of the house 'SAFELy' of course – as long as my wife doesn't know about it.

Phil H

[Phil H1Participant @philh196021]

Sorry for hijacking the thread but if there are 2 litres of 95% acid and I mix them 10:1 with water (to be diluted to 30:1 when needed) that would give 2 off legal 10l storage bottles. Is that about right?

Phil H

[SillyOldDufferModerator @sillyoldduffer]

Posted by Phil H1 on 24/07/2018 13:37:08:

Sorry for hijacking the thread but if there are 2 litres of 95% acid and I mix them 10:1 with water (to be diluted to 30:1 when needed) that would give 2 off legal 10l storage bottles. Is that about right?

Phil H

If (big if) I got the sums right, that's OK

You can't legally own stronger than 35% by weight.

As 2 litres of fully concentrated acid weigh 3.7kg you need about 10 kg of water to dilute it to 37%. 10 litres of water weighs 10kg, and your acid is 95%, so job done.

Dave

[pgk pgkParticipant @pgkpgk17461]

When is this army of government inspectors going to search every hobby-shed?

Of course we live in a society of mind-numbing rules where every A&E dept has to have a green first aid kit.

pgk

[not done it yetParticipant @notdoneityet]

Technically 1:10? But that may well result in 22 litres unless there is a change in volume on mixing.

A check on the density of the resultant solution would provide the actual volume, if the density of the 95% part is known.

From my Merck chemical table booklet, there is a contraction in volume when diluting 97.5% sulphuric to battery acid concentration.

2.666 litres of acid mixed with 7.895 litres of water yields only 10 litres of battery acid.

I suggest you aim for about 18 litres by mixing the acid into water and dilute the resultant mixture to 20 litres when cooled.

[not done it yetParticipant @notdoneityet]

Technically 1:10? But that may well result in 22 litres unless there is a change in volume on mixing.

A check on the density of the resultant solution would provide the actual volume, if the density of the 95% part is known.

From my Merck chemical table booklet, there is a contraction in volume when diluting 97.5% sulphuric to battery acid concentration.

2.666 litres of acid mixed with 7.895 litres of water yields only 10 litres of battery acid.

I suggest you aim for about 18 litres by mixing the acid, with stirring, into water and dilute the resultant mixture to 20 litres when cooled.

[SillyOldDufferModerator @sillyoldduffer]

Posted by not done it yet on 24/07/2018 20:33:59:

Technically 1:10? But that may well result in 22 litres unless there is a change in volume on mixing.

…

2.666 litres of acid mixed with 7.895 litres of water yields only 10 litres of battery acid.

…

Always happy to have my dodgy maths put right, but I may be innocent this time.

My calculation is by weight rather than volume because the regulations specify concentration by weight. I thought it better to do the sums their way.

Also, Phil H isn't trying to make battery acid, he's watering down his acid to stay legal. I'm pretty sure that adding 10kg of water to 2 litres of acid will do the trick and that two 10 litre containers will hold the diluted result.

pgk pgk is right to say our sheds are unlikely to be raided. There would be trouble though if concentrated acid was stolen and traced back to the original owner, especially if it had been used in a crime. It would be ironic to suddenly find yourself in a cell because the police recovered your stuff and noticed you were a crimbo too!

Dave

[pgk pgkParticipant @pgkpgk17461]

Posted by SillyOldDuffer on 24/07/2018 21:48:39:……l because the police recovered your stuff ….

Dave

That's a bit far fetched isn't it? All i ever got was "If you don't know who did it then we're not going to find them" and "Sorry you've been the victim of crime.. your crime number for insurance is xxxx"

pgk

[not done it yetParticipant @notdoneityet]

Dave,

I was replying to Phil H1, not you. I did not even read your post, to be quite honest. Procedures in chemistry can be important. Mixing ten lots of acid with one lot of water, in this case, was obviously wrong – he only has two litres of acid and wanted 20 litres of product to dilute further, later.

I gave an example of diluting sulphuric acid that involved about 10 1/2 litres of liquid which provided 10 litres of product. He would likely finish up with less than 20 litres, but at that point, I didn’t know. – I was not prepared to guess or work it out. I’m a chemist, so precision dilutions were more my line of business.

I then gave a good simple idiot-proof plan for achieving 20 litres of product. A practical plan.

BTW, we now have you writing the wrong procedure once more. Always add conc sulphuric to water, never the other way round as you sloppily indicated in your post. Very misleading of you, and could lead to serious personal injury for anyone following your indicated order of operation. ACID TO WATER EVERY TIME (with agitation) is the correct, safe method. The alternative is dangerous.

[SillyOldDufferModerator @sillyoldduffer]

Posted by not done it yet on 24/07/2018 23:31:55:

Dave,

I was replying to Phil H1, not you. I did not even read your post, to be quite honest. …

Bit of confusion here, I thought we where both addressing Phil's later question, which was:

… if there are 2 litres of 95% acid and I mix them 10:1 with water (to be diluted to 30:1 when needed) that would give 2 off legal 10l storage bottles. Is that about right?

I think that's 'about right', noting that it's only necessary to use 10kg of water to render the acid legal. Do you agree?

Dave

[Keith HaleParticipant @keithhale68713]

WOW …………..

All getting a bit personal now.

It will be handbags at dawn next.

Get me a ticket! Can't wait!

Keith

[Phil H1Participant @philh196021]

Thanks very much chaps. I will go on the safe side with the mixing because according to my Rob Roy book – 30:1 is good as a pickling solution – so 10:1 ish is fine for storage.

pgk is sort of right i.e., what army of loons are going to inspect sheds and garages round the country but stranger thinks have happened and these days if a prosecution is easy – the morons will go for it.

My chief concern of course is what happens if I have an accident or worse. I don't want to leave my wife in a 'pickle'. I am joking when I say I won't tell her about the storage – I will and more importantly – how to deal or at least who could deal with all my other tools etc.

Phil H

[nigel jones 5Participant @nigeljones5]

For heavens sake never ever add water to sulphuric acid. If its a strong acid it will literally blow up in your face.

[Author]

Posts