citric acid: how to handle it

[ghostdancing]

i've just bought 1kg of citric acid,plan is to use it as rust remover to clean some scrap steel for tig weding practice..can you explain how to make the job?

water solution: how much citric for liter?
how many hours must be duration of the bath?
after bath: have to rinse the metal in clean water?

edit: just saw the thread about it..i'm going to reed it..

 

[badabec]

Wear gloves when you rinse the items, the metal really stinks and seems to get into your skin.

 

[awemawson]

Frankly it's pretty benign, and unless you have cuts or scratches it won't hurt you, after all it's only lemon juice !

I've used gallons of the stuff over the years and never had a problem - as for smell, perhaps I'm not over sensitive but it's never bothered me.

Mind you it's good stuff !

 

[Onoff]

Just use these instructions for Deox-C

 

[ghostdancing]

i just made a test, put 4 soup spoons of powder in 1 liter, let the bucket in the sun (here is hot these days)..will wait the citric soup makes its magic..

 

[The_Yellow_Ardvark]

i've just bought 1kg of citric acid,plan is to use it as rust remover to clean some scrap steel for tig weding practice..can you explain how to make the job?

water solution: how much citric for liter?
how many hours must be duration of the bath?
after bath: have to rinse the metal in clean water?

edit: just saw the thread about it..i'm going to reed it..

How long is a piece of string?

Mix?
Star with 1Tbl per litre of water, mix well. Add steel to a plastic container, add more citric acid until bubbles form on the surface of the steel.
Wait, check until red oxide is converted to black oxide.

Rinse well with water and dry well.

Simplz.

 

[pedrobedro]

You can make bath bombs with it so it's pretty safe stuff, chuck as much as you want in. I never figured out the optimum amount and I'm not sure if it's the stronger the better or enough is enough.

 

[marlinspike]

They use it to make fizzy pop, so unless you get it in a cut, it's safe as houses. I just pour the used stuff in the manky bit of the garden to be honest. Hasn't harmed it.

I find it helps to add boiling water to the container after a day or so. Seems to reinvigorate the solution a bit. Also, get as much loose rust off as possible first so the citric acid is working on the actual rust not the flakey bits.

 

[Onoff]

Best to degrease whatever first.

Brush or knock off loose rust.

Degrease again if necessary.

Doesn't hurt to periodically haul it out and wire brush the heavy rust. Rinse under the tap / hose before putting it back in the citric.

Be very careful leaving hardened stuff/edges in there too long.

If you can heat the solution and keep it heated to 70degC it works really, really fast.

As aforementioned I first bought Bilt Hamber's Deox-C. Pretty much the same stuff everyone thinks. Just treat citric acid powder as you would Deox-C and use the pdf instructions I posted above.

 

[MattF]

Just

Wear gloves when you rinse the items, the metal really stinks and seems to get into your skin.

That smell is nauseating, or at least to me.

 

[ghostdancing]

well it worked a treat! roughly 24 hours, the parts are clean..

 

[slim_boy_fat]

well it worked a treat! roughly 24 hours, the parts are clean..

[for "thread", read 'post' ]

 

[ghostdancing]

you're right mate..do i must host my pictures on a hosting website or can attach directly from my pc?

however have to say that when i welded on the cleaned pieces, i had some fumes from the yellow patina left on it by the citric acid.. i washed in streaming water while scrubbing with a brush, but beeing square tubes, the inside cavities were not washed well

 

[badabec]

No need to host, just download direct from your pooter. Then pick thumbnail or full size.

 

[VeryFEDUP]

Rather than start another thread, I hope the OP won't mind me asking here. Does stuff have to properly soak to get the rust off?
I have to clean rust off some lengths of railway line; just the tops and running edges. I can do it with a belt sander and an angry grinder but I did wonder if I could use citric instead?
Maybe tear old towels into strips and soak them in solution and drape over the rails? I guess it would take at least 48 hours with maybe a top up required?

 

[Barking Mat]

I wire brush everything before and after, really helps.

Then rub in some beeswax and linseed oil. Tip courtesy of @The_Yellow_Ardvark .

 

[awemawson]

I have heard of folks making up citric acid with added wall paper paste to make a gel, but I've never done it myself.

I think you need the volume of the water to be effective. It forms iron citrate from the rust and this is water soluble so goes into the solution exposing more rust to treat, unlike for instance using phosphoric acid where the iron phosphate isn't water soluble and forms a hard layer.

 

[premmington]

Citric acid is what we use to descale kettles...

Water is hard in Norfolk. Works a treat...

Think the stuff you buy "OUST" is Lactic acid (not sure of this fact?).

Can you not make lemonade from Citric acid powder?

 

[Onoff]

Rather than start another thread, I hope the OP won't mind me asking here. Does stuff have to properly soak to get the rust off?
I have to clean rust off some lengths of railway line; just the tops and running edges. I can do it with a belt sander and an angry grinder but I did wonder if I could use citric instead?
Maybe tear old towels into strips and soak them in solution and drape over the rails? I guess it would take at least 48 hours with maybe a top up required?

For long things you can use lengths of guttering capped at both ends. Lines of bricks with damp proof membrane laid in to form a well. Etc.

There is a Deox-C gel. Never tried the wallpaper paste trick...

 

[VeryFEDUP]

Thanks everyone. I was hoping to avoid too much dust. I have bodged a coupling so that I can attach Hetty vacuum to the belt sander. I'll just use the angry grinder to finish off.