Rust in bottle

Hi all,
i just got some bottles back from a colleague at work (he was kind enough helping me to empty them of my last batch) and somehow a paper clip made its way into one of the bottles, leaving a nice rust spot at the bottom of the bottle. I searched around the internet a common theme seems to be to use some kind of acid to remove it.
I started at the bottom of the acidity scale and used vinegar. Now the vinegar has been sitting in the bottle for 3 days and the rust spot looks as good as new.
Does anyone have any other ideas I could try?
It's not just a regular bottle, it's one of my 'special' 0.65 L bottles from Germany, otherwise I would have just tossed it.

Oxalic acid

Where would I look for that? Any commercially availble cleaners that contain oxalic acid?

also check a hardware store or some place like that for naval jelly it is jelly that contains phosphoric acid and it'll eat the rust

Thanks for the advice guys.

Paint stores carry it for bleaching wood. Rhubarb leaves are probably around 0.5% oxalic acid, not that that helps any.

Have you tried a bottle brush?

-a.

bar keeper's friend? make a paste, drip it to the spot, then remove after a few minutes?

You can get oxalic acid (dry powder form) from a darkroom photography chemical supply store. Photographer's Formulary is one such source. http://www.photoformulary.com I don't have a good idea what solution strength you should use, but start with a low concentration.

I bet that standard battery acid (roughly 35% sulfuric acid) should do the trick. Be careful, though. It can burn you quite badly. Get it at an auto parts store.

this is one single bottle right? I realize it's kind of special to you and all, but this seems like a lot of work to go through to get the rust off.

Personally, I'd just clean it as best I could with vinegar and a bottle brush and then just use it. Rust won't kill you and the beer will eventually clean it for you.

-walker

Do you mean 0,5 liter bottle? I have several hundreds of them.

I don't recall any 0,65 liter bottles.

All this fuss over 1 bottle...toss it.

homebrewer_99 said:

Do you mean 0,5 liter bottle? I have several hundreds of them.

I don't recall any 0,65 liter bottles.

All this fuss over 1 bottle...toss it.

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You can find 0.65 L bottles in germany. IN fact, I seem to recall them being relatively easy to find.

Walker-san said:

You can find 0.65 L bottles in germany. IN fact, I seem to recall them being relatively easy to find.

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Are you talking our 22 oz equivilants? Their 0,5 liters are our 16.9 oz...I also have several 640 ml which is 0,64, but not 0,65.

I'd still toss one bottle for all the work it's caused...be done with it. Set it aside for a display...

homebrewer_99 said:

I also have several 640 ml which is 0,64, but not 0,65.

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yeah, that's probably what I was thinking of. I just remembered equating the bottles to a 22oz-er.

I'd suggest not buying oxalic acid if you plan on drinking from those bottles. Its the same substance that makes rhubarb leaves poisonous. Residual won't kill you but it might make you have some serious gastrointestinal upset.

You could use "muriatic acid" (aka hydrochloric acid) which hardware stores sell. You have to be careful with it and wear safety goggles and gloves, but it isn't toxic. You can dilute it to about 1 molar concentration and it should still work, which would be about a 1 in 11 or 12 dilution, just remember that when you dilute acid always add acid to water. 1 molar HCl is pretty tame (it burns like hell if you get it on a cut though) but it still does a decent job of dissolving rust. The lab I work in does iron chemistry and we use it all the time. And you can always use the leftover acid for things like cleaning soap scum and calcium deposits if you have problems with them.

Walker-san said:

yeah, that's probably what I was thinking of. I just remembered equating the bottles to a 22oz-er.

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Mmmmmkay!

homebrewer_99 said:

Do you mean 0,5 liter bottle? I have several hundreds of them.

I don't recall any 0,65 liter bottles.

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0.66Litre Bottles are now used in the UK for specialist Cider - 0.50Litre is still the standard for beer in the Stores. I'm not that keen on the bigger version. I personally don't like to drink sediments so the extra brew sits in the bottle mixing with it unless you fuss about with a bigger glass than a Pint or (heaven forbid!) you share the brew with someone else.
Like you I'll stick with my half litre versions for Homebrewing!

Caplan said:

Like you I'll stick with my half litre versions for Homebrewing!

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...and they match my glass's capacity so well......0,5 l...

Bathroom lime remover? Tile cleaner? Maybe you already have some under the sink.