Oxalic acid--the next step

[lydiamight]

OK--so I've now got hold of the Oxalic acid crystals. Can anyone tell me to what strength I dilute i.e. what weight of crytals to what volume of water? Should I dilute it with hot water to make the crystals disolve more easily? I'm sure that I've seen some mention of mixing it with wall paper paste so that it will cling to vertical surfaces has anyone tried this? If I accidently spash any of the solution onto stainless steel stanchions/fittings etc will it stain the stainless steel?
All contibutions gratefully received.

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[VicS]

Because oxalic acid is not fantastically soluble I would aim for something approaching a saturated solution. Unfortunately I cannot find a precise figure for the solubility only a vague statement of one part in 8 parts of water at 20C. Taking this at face value it means that 100 cc of water will dissolve 12.5g of solid (or in old money 1 pint will dissolve 2½ oz).

If you are likely to be working at a lower temp than 20 reduce the concentration a little.

You can use warm or even hot water to speed up the dissolution process. Yes the use of wallpaper paste is a well known trick. I would avoid splashes on metal fittings as some staining will probably occur.

Remember oxalic acid is poisonous so avoid ingestion, wear goggles and gloves and wash any splashes off the skin. Clearly label any solution you may wish to store. Wash away any spillages with loads of water and safely dispose of all residues. Keep out of childrens reach.

<hr width=100% size=1><font color=purple>Ne te confundant illegitimi.</font color=purple>

 

[Gunfleet]

I use it 1/10 so Vic's figures sound about right (or mine do!). It's worth noting that oxalic acid is good at getting rid of rust stains - it got rid of some really persistent ones ion conceret in our back yard - so as you suggest it might be worth keeping it off your stainless.

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[asj1]

Have been following this series of posts with interest -- and so as not to miss out will try and get some myself, but can you just remind me what is it ultimately being used for/ what are you going to clean with it?

Andrew

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[AIDY]

I've only used oxalic for cleaning my teak decks. But I believe it will remove most stuborn stains from GRP as well but not tried it myself.

<hr width=100% size=1>/forums/images/icons/wink.gif <font color=blue> Regards Andy </font color=blue>

 

[lydiamight]

My intention is to try to clean the decks and topsides of an average not very white boat

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[geoffatstanpit]

I just got a kilo of oxalic acid in the post from www.agwoodcare.co.uk.

Bayley's Chemists' Pocket book gives its solubility as 9.5% at 15c. This ties in with the label on Y10 which states less than 10%.

I tried 8% and enough wallpaper paste (B&Q) to make it a bit stiff (about a dessertspoon in 300cc.

It got the brown stain off my topsides exactly like Y10 and hosed off afterwards without any trouble.

But it is a bit lumpy and I think there must be a better thickener. It would be useful to have it coloured so you can see how thick it has gone on and whether you have washed it all off afterwards. Could there be a useful suggestion in the punctureproof trolley wheel thread?

Geoff

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[tillergirl]

The classic mixture is 25 grams to 500cc of water but its not an exact or critical science. It did not stain stainless in my experience. Warm water definitely helps dissolving. Wear some gloves. Repeat appilication as necessary.

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[cliff]

Will lift the anodising off aluminium after prolonged exposure, will clean rust marks of stainless steel - may take the shine of polished SS but that is easily remedied with some metal polish and a bit of elbow grease.

Oxalic acid is extremely dangerous stuff to play with as it can be absorbed through the skin and even in small doses can lead to kidney failure. Always use proper protective clothing including face shield, gloves, smock etc.

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[pappaecho]

As oxalic acid has lowish solubility, the best way to produce a solution is to slighly overdoes so that some remains undissoved in the bottom of the container. Filter off the liquor, mix with wallpaper paste, and Robert is Your Uncle. The best remover of rust stains is citric acid, which is best bought from winemaking shops and unlike oxalic acid, it is used in food and is definitely not poisonous.. stiil dull stainless tho'

<hr width=100% size=1>Def: Yachting - a way of spending the kids inheritance