bulk citric acid powder?

[tombear]

Having just been introduced to the rust removing wonder that is citric acid (where have you been all my life?! ;-{D) could amyone tell me where I could buy a bag of the stuff, say up to 5 lb? All I can get locally is the little tubs for brewing and I want to de rust the stockpile of old tools I have amassed.

I have tried vinegar which works well enough but some of the tools have wooden parts that can't be removed and I'd rather avoid the staining you get using vinegar (and the smell and the mess).

Thanks!

ATB

Tom

 

[Langers]

Ooh be careful, that can be used for making HMTD explosives. It will be on a bulk buy watch list somewhere.

GCHQ if your listening, its not my knowledge, read it somewhere this week by coindidence.

 

[rik_uk3]

Citric acid works well but be very careful, you can bugger brass up if you over soak, the brass turns pink and it takes a lot of hard work to get the colour back (I still use vinegar).

Have you tried the electrolytic method? I use this a lot on camp stoves these days and it works very well.

http://www.instructables.com/id/Electrolytic-Rust-Removal-aka-Magic/

If you must use citric acid try buying in bulk from a home brew supplier.

 

[British Red]

Try Art of Brewing online Tom

 

[jimford]

Citric acid works well but be very careful, you can bugger brass up if you over soak, the brass turns pink and it takes a lot of hard work to get the colour back (I still use vinegar).

The acid reacts and dissolves the zinc in brass, leaving the copper which gives the pink colour. You have to mechanically remove the surface copper to get back to brass again. Or you could bright dip it as below.

For bright dipping brass, I found this on the net:

Here is a quick and efficient "old-time" bright dip for copper and brass. Make a mix of 85% by volume Phosphoric Acid, and 15% by volume Nitric Acid. Mix the two thoroughly. Use at room temp. When you put a part into it, as soon as the part becomes covered with fine bubbles - it is done! Although I would NEVER EVER recommend it, I have gotten my fingers in this solution and have had time to rinse it off before any burning was ever felt. This can make copper, "new penny bright." Good luck, and remember to treat the chemicals properly and with respect. Used carelessly they can injure, and cause safety issues.

I only managed to get a small quantity of phosphoric acid, so only tried it on a small item. It worked a treat! 'Milkstone remover' used in milking sheds is phosphoric acid, and I've been on the look out for it but not found any yet.

Jim

 

[tombear]

Cheers for all the advice folks,

I've just polished up and oiled some lovely old Sheffield and Birmingham brace bits and they have come up a treat.

The advice about the effects on brass was timely, I've just cleaned up a old "Cleerout" tin opener with a brass collar and you stopped me soaking that. I've a Horlics mixer that I use for soaking tool handles in linseed oil (actually a mix of various wood preservatives thats been tipped into a old SRD jar over the years, teak oil, tung oil, various sorts of linseed and what have you) and I stood it up in that before pouring the citric acid solution in to within a nats of the collar. It's come out lovely and I have a sliding collar can opener soaking now.

The wife also found this on the web

Citric Acid 1 KG.
www.MeridianStar.co.uk 1 KG Citric Acid £9.99. Free U.K. Delivery.
5 Kilogram Bag £22.99

https://www.soapkitchenonline.co.uk/acatalog/Bath_Bomb_and_Dry_Toiletry_Ingredients.html

Citric Acid Granular Fine (monohydrate) 1Kg £3.75 + £5.00P&P
Citric Acid Granular Fine (monohydrate) 2.5Kg £8.55 + £5.50 P&P
Citric Acid Granular Fine (monohydrate) 5 Kg £15.40 +£7.49 P&P
Citric Acid Powder (anhydrous) 2.5Kg £10.80 +£5.50 P&P

Being ignorant of chemistry, whats the differance between monohydrate anhydrous?

Cheers!

Tom

 

[stijnb]

monohyrate contains crystal water, doesn't matter for this purpose anyway.