Which household products contain enough oxalic acid?

[wipe_out]

I want to clean some rust stains off the GRP this weekend.. It's too late to order oxalic acid online and be sure to get it by Friday afternoon so I need to get something from the high street..

The usual selection of shops around eg. Sainsburys, Tesco, Wickes, Halfords etc..

I have looked at the Harpic toilet cleaner with lime scale remover and it contains Hydrochloric acid.. Other cleaners in the house I have looked at have citric acid but nothing so far with oxalic acid..

Which household products available in these stores would have a high enough concentration of oxalic acid to do the job??

Thanks..

 

[sailorman]

I want to clean some rust stains off the GRP this weekend.. It's too late to order oxalic acid online and be sure to get it by Friday afternoon so I need to get something from the high street..

The usual selection of shops around eg. Sainsburys, Tesco, Wickes, Halfords etc..

I have looked at the Harpic toilet cleaner with lime scale remover and it contains Hydrochloric acid.. Other cleaners in the house I have looked at have citric acid but nothing so far with oxalic acid..

Which household products available in these stores would have a high enough concentration of oxalic acid to do the job??

Thanks..

how about oxalic acid from a chemist
or boil up some rhubarb leaves

 

[AngusMcDoon]

Or Y10 from a chandlers if you can get to one.

 

[Rigger Mortice]

how about oxalic acid from a chemist

+1 Any chemist can order it in (usually next day) but not all are willing to do so. I've had more luck with independents who don't seem to be tied down with Head Office rules.

 

[VicS]

I want to clean some rust stains off the GRP this weekend.. It's too late to order oxalic acid online and be sure to get it by Friday afternoon so I need to get something from the high street..

The usual selection of shops around eg. Sainsburys, Tesco, Wickes, Halfords etc..

I have looked at the Harpic toilet cleaner with lime scale remover and it contains Hydrochloric acid.. Other cleaners in the house I have looked at have citric acid but nothing so far with oxalic acid..

Which household products available in these stores would have a high enough concentration of oxalic acid to do the job??

Thanks..

I am not aware of any household products which contain oxalic acid. Far too dangerous. iirc Seajet got a splash or two on himself and it nearly killed him!

The Harpic limescale remover contains HCl as you have discovered.

Cillit Bang Lime and Grime contains sulphamic acid. Just this week used that to effectively clean some heavy rust staining and deposits from a length of rope.

Citric acid will do it but less effectively than oxalic.

 

[Alpha22]

Bar Keepers Friend is available from some of the bigger Asda's. Not sure about other supermarkets.

 

[wipe_out]

Thanks for the chemist suggestion.. Don't know why I didn't think to try that.. I think there is an independent one that may get it for me.. Failing that I might need to make a detour to ASDA on the way to the boat..

 

[Lakesailor]

I had no luck whatsoever with chemists, chain or independent.Most had no idea what I was talking about.
Get Astonish cream oven cleaner. Safe on GRP. I cleaned up all the decks (including bad rust stains) on my motor boat with it.

 

[Woodlouse]

Why don't you just pop into a chandlery and buy some rust stain remover?

 

[agurney]

I am not aware of any household products which contain oxalic acid. Far too dangerous. iirc Seajet got a splash or two on himself and it nearly killed him!

The Harpic limescale remover contains HCl as you have discovered.

Cillit Bang Lime and Grime contains sulphamic acid. Just this week used that to effectively clean some heavy rust staining and deposits from a length of rope.

Citric acid will do it but less effectively than oxalic.

Sadly, recent formulations of Cillit Bang Lime and Grime don't remove rust stains - confirmed with correspondence with Reckits.

 

[VicS]

Sadly, recent formulations of Cillit Bang Lime and Grime don't remove rust stains - confirmed with correspondence with Reckits.

It worked well enough for me this week. Cillit Bang Power Cleaner Grime and Lime. "New formula". Nearly full bottle so cannot be very old.

Removes rust stains according to the label.

Contains sulphamic acid, formic acid and oxalic acid according to rbeuroinfo.com


There is a newer or alternative product, I think, Power Cleaner Limescale and Shine. It contains sulphamic acid and oxalic acid. It also, as you would expect, removes rust stains according to their website.

Is it true that Cillit Bang Power Cleaner Limescale & Shine is effective against rust spots?
Yes. Cillit Bang Power Cleaner Limescale & Shine is highly effective against tough stains, dirt, limescale and even rust.

 

[Daydream believer]

Seajet got a splash or two on himself and it nearly killed him.

Perhaps if you tried again but using a bit more !!

 

[agurney]

It worked well enough for me this week. Cillit Bang Power Cleaner Grime and Lime. "New formula". Nearly full bottle so cannot be very old.

Excellent, thanks.

 

[Neil_Y]

If you have a home brew shop nearby they will sell citric acid in crystals so you can make it as strong as you like, I've recently used this to dissolve a tap that was jammed in SS no rust (or even metal left after a couple of weeks)

 

[121]

eBay.

Bought a 5lb bag of the stuff.

 

[prv]

It's too late to order oxalic acid online and be sure to get it by Friday

eBay.

D- for reading comprehension

Pete

 

[VicS]

If you have a home brew shop nearby they will sell citric acid in crystals so you can make it as strong as you like, I've recently used this to dissolve a tap that was jammed in SS no rust (or even metal left after a couple of weeks)

Please dont confuse concentration and acid strength.

Although citric acid is more soluble it is a significantly weaker acid than oxalic acid. The reason it is somewhat slower in its action. It is a little stronger than acetic acid. Oxalic acid is in fact the strongest of the common weak organic acids.

Sulphamic acid is a little stronger than oxalic acid

Approx pK_avalues:

Acetic 4.76

Citric 3.13

Oxalic acid 1.27

Sulphamic 0.99​

The effectiveness of citric and oxalic acids in removing rust stains is also due to their ability to chelate the ferric ions as soluble complexes

 

[ChattingLil]

Try Harpic.

 

[VicS]

Try Harpic.

Already mentioned.

There are however many products carrying the Harpic brand name. Only those which are limescale removers are likely to be effective

 

[Neil_Y]

Please dont confuse concentration and acid strength.

Although citric acid is more soluble it is a significantly weaker acid than oxalic acid. The reason it is somewhat slower in its action. It is a little stronger than acetic acid. Oxalic acid is in fact the strongest of the common weak organic acids.

Sulphamic acid is a little stronger than oxalic acid

Approx pK_avalues:

Acetic 4.76

Citric 3.13

Oxalic acid 1.27

Sulphamic 0.99​

The effectiveness of citric and oxalic acids in removing rust stains is also due to their ability to chelate the ferric ions as soluble complexes

Thanks Vic, I should have paid more attention in chemistry