acid

hi how do you stop mould growing in your citric acid it is in a close container(barrel)with sealed lid thanks dave

Dave,

Can light get into the box, to stop mould it has to be light proof otherwise mould will grow.

Martin P

Hi David,

Try and get some benzoic acid and put that into the citric acid container. Benzioc acid will reduce/stop the growth if microorganisms. As Martin says, use a lightproof bottle.

Thor

Edited By Thor on 01/11/2013 17:44:44

Boric acid (also known as boracic acid) will also inhibit mould growth. This used to be available from chemists but I have not purchased any for 10 years or more so I am not sure whether it is still available.

Also copper in solution will also prevent mould growth. You could heat up some old copper tube to form a coating of black oxide. This should dissolve in the citric acid and it will turn slightly blue. Leave the copper tube in the liquid.

Mike

I find that Tupperware gets infected with mould spores, the growth can be restricted, I'v got a large container in the kitchen for kitchen scraps, and it often gets furry.

Bleach in the acid would tend to neutralize the mixture. Forget the mould, it's doing no harm. Ian S C

I even get algal growth in my sulphuric acid bath. It takes a lot to kill the little blighters! But as has been said, just ignore it.

Russell.

Edited By DMB on 02/11/2013 11:46:14

Looks like someone has discovered the origins of life. Fungus in Acid and Mould in Sulphuric, please dont mix the two together or you might make a new life form.

Makes one wonder how Primordal life started?

Clive

A splash of household bleach, added when the mix is made, prevents any unwanted growth, at least , this has been my experience when using citric acid.

regards,

David.

Try some sodium metabisulphate from your home brewing shop.

Rik

Thinking again - what's all this with citric acid? If this is being used these days for pickling copper prior to silver soldering then it is a new one on me. Going back 30 years or so everyone seemed to be using dilute sulphuric acid - I know I did.

Fill me in someone please.

Rik

Citric acid works fine as a pickle, it has the minor advantage that it won't melt you into a steaming puddle or burn holes in your clothes like sulphuric

Neil

Is Citric acid available on the local market...where do you get it from, Chemists, garden centre's,.. liquid, powder form etc..? Interested for future ref.

George

Elfin Safety could not care a toss about home workshops, only in Employment situations to protect the poor workers!

Is sulphuric acid really more dangerous than citric.?

It has been stated that citric acid works slowly. This is because the solution is low in acidity (the PH is not very low). If you use a weak solution of sulphuric acid such that the PH is the same it will take equally long to work but should be no more dangerous than citric acid.

Sulphuric acid is available here (France) in all DIY stores and many supermarkets. It should be available in the UK as battery acid. I buy 30% strength and use it diluted 10:1 with water. It works in a few minutes. Dilute it more if you are worried about safety but always remember to add the acid to the water not the other way round.

Russell.

As I understand it, the issue is in the transportation of liquid acids (read that as by post). Parcelforce classify sulphuric acid as dangerous good so suppliers cannot just mail it as they used to. I suspect they don't sell that much anyhow so moved over to dry acid salts. That said battery acid packs are obtainable by post/courier but that would be diluted acid and fairly small quantities. For boilermaking especially in larger scales (or should that be de-scales) you tend to require quite large volumes which is why sulphuric acid was preferred as it could be diluted will a large volume of water.

Martin

One Shot (?) drain cleaner is easily available from B&Q etc. and is something like 90% sulphuric acid. Make sure you get the one that is sulphuric acid based though. It's available from Ebay as well so must be able to post it!

I do use citric acid but still prefer sulphuric acid for copper.

John

Russell - yes sulphuric is much more dangerous than citric. You can lower a piece of copper tube into sulphuric and listen to it crackling as the acid burns of the scale and you get it on your flesh at your dire peril. Compared to the relative docility of citric acid, sulphuric is an angry beast - it does a lovely job though - and quickly!

Rik

Edited By Rik Shaw on 04/11/2013 15:47:12

As I said, it depends on the strength of the solution. A weak solution, less active and less dangerous.

You can buy battery acid ( about 35% w.w. sulphuric acid) by post. For example

Russell

Gentlemen,

See Royal Mail website - Corrosive Substances

caustic soda, acids, dyes, metal cleaning products and other corrosive materials CANNOT legally be sent by post.

Acids include liquid soft solder fluxes.

Dry flux powders and salts are OK.

Other suppliers via ebay may think otherwise.

Keith