Oxyalic Acid

[boatmike]

OK so I have used Y10 before and its great but expensive so I have half a kilo of Oxyalic on order at six quid and know that some of you guys have mixed it with water and wallpaper paste to do the same job. My question before I do something silly is what proportions do you use? Assuming say 5 litres of water as its a cat and I want to go over the whole boat, how much Oxywhatsit do I dump in? Do I add water to acid or acid to water? Is it terribly volatile like hydrochloric or fairly benign to handle? I assume the wallpaper paste for thickening it up you only need a little bit to stop it being runny and add this last? Again assume apply with brush and hose or pressure wash off after? How long after?
Oh and I assume it won't act as a stripper for the antifouling when I hose it down will it? /forums/images/graemlins/tongue.gif

 

[trouville]

I buy it from any chemist (in France) i just buy 50 grams its a dry crystal and i put a tea spoon full into a 3/4 full jam jar with tepid water.

Its extreamly poisenous so dont wipe your mouth with your hand and where gloves!I have a wooden boat, so my use is different to yours i put it on stained wood to take the black away.

If you dont get a good reply, do what i do and try different concentrations on small areas. For bad stains i took an old piece of wood and tried different strengths, for plastic you could mix up some gel/walpaper glue! and start with 2or 5% work up to 20% i suppose as you want a white to be white the consentration up to a points not critical, try 20% leave it for an hour and wash it off, providing the wallpaper glue dosent set????(just try a couple of sq cms)

Good luck

 

[Vara]

http://www.ybw.com/forums/showflat.php?C...true#Post695314

http://ptcl.chem.ox.ac.uk/MSDS/OX/oxalic_acid_dihydrate.html

These might help

 

[boatmike]

Yes I saw this thread but I was hoping someone who has done it would be able to answer my particular questions as it's all a bit vague. Failing this I will of course experiment.

 

[MacW]

Half a kilo is probably enough to clean the Empire State building!
Most proprietry brands of cleaner contain only 10% oxalic acid.The wallpaper paste is added to turn the mix into a gel so it can stick to the hull. There have been a number of posts on this recently, from where you might get an idea of how much of the crystals to add to say half a gallon of water. The stuff is extremely effective, almost magic but be sure to rinse it all off using copious amounts of water. As has been said, it is extremely poisonous and no risks should be taken regarding possible ingestion or transfer from hands to mouth or body.
PS. Wiping over your hull with slightly wet rhubarb leaves has the same effect! They contain large amounts of oxalic acid.

 

[boatmike]

Slightly wet Rhubarb! Are you winding me up? I eat Rhubarb and I ain't dead yet....
Mind you I don't eat the leaves I suppose....... Yes I know its a lot but it was the smallest pack I could get and at £6 who cares?

 

[Ningaloo]

I also use oxalic acid, bit it seems to be getting harder to buy now. I have a small independant phamacy where I can but it. Boots and high street chains usually won't be interested in ordering it because of health and safety.
I usually add a table spoon or so to a large bucket and it works great.

As well as gloves, remember to wear shoes until you have washed it off - I forgot once and I'm now 2cm shorter

 

[boatmike]

At a tablespoonful to a bucket I have enough to last me till I won't care anymore! Thank you for that. I note from the other thread that people have used hot water. Wouldn't have thought that was necessary myself but I will certainly follow your recommendations and wear glasses,hat, gloves, boots and a cricket box. Must protect all essential equipment....... Look on the bright side. You wont need to cut your toenails again...

 

[EdEssery]

Half fill a bucket with hot water. Add Oxalic acid crystals stirring as you go (I use an old wooden spoon kept for the purpose - it's very clean!). Keep adding crystals until you've added them all or until no more will dissolve (a saturated solution). I generally find 500g will make up about half a bucket full and I always end up throwing some away. Let Oxalic acid solution cool. Add one small sachet of wall paper paste (the size that does four rolls of wallpaper) - stir in and leave for five minutes. Paint onto the hull with an old pasting brush. Leave for 20 minutes and then hose/jetwash off. Wear old clothes, rubber gloves and goggles. Wash off any splashes on skin with fresh water immediately.

Good luck.

Ed

 

[boatmike]

Thank you Ed but others have suggested a far lower concentration works well. How did you come to the conclusion that you needed 500gm per half bucketful? Have you ever experimented with a lower concentration?

 

[VicS]

Re: OXALIC ACID

Oxalic acid (correct chemical name: ethanedioic acid) is available from AG Woodcareat £8.72 per Kg. (Also in 5, 10 and 15 kg quantities at proportionally lower prices).

They recommend a solution strength of 4oz per pint and also recommend dissolving in hot water. (It dissolves rather slowly in cold water).

The main main hazard is its high toxicity so avoidance of ingestion is paramount.

Apart from that it is easy to handle, it is a colouless crystaline solid, it is what is classed as a weak acid so is not corrosive like sulphuric and hydrochloric acids, although non metallic vessels should be used for mixing, handling and storage. It is odourless, produces no fumes and is not volatile.

I believe absorbtion through the skin is also possible so rubber gloves should be worn, especially when using the solution. Splashes on the skin should be washed off promptly. Goggles should always be worn when handling any chemicals also, if you consider it appropriate, a plastic apron (improvised from a bin bag perhaps) or some old oilies.

If you want to apply to a vertical surface add, as suggested by by others, wallpaper paste granules to the cooled solution in the same concentration as you would for normal use.

Clearly label the solution you prepare and store any that is unused in a safe place or dipsose of it.

Information on rhubarb can be found at http://www.rhubarbinfo.com/

I suggest that if you try cleaning your boat with rhubarb leaves you'll be back asking for advice in removing the green stain they leave behind.

 

[boatmike]

Re: OXALIC ACID

Excellent! Thank you Vic. Thanks to you I not only know that I have enough of the stuff coming to kill 20 people, but know a great deal more than I care to about Rhubarb...... All I have to do now is look up 4 oz to see how many grammes that is....... er about 100 I think so that makes 5 pints= 500Kg which actually makes Eds solution at 500g to half a bucket a weak solution assuming his is a 2 gallon bucket dunnit? I wont do half the empire state building after all.... However I think Seaboots might have a case in that cleaners like Y10 are not neat Oxalic acid. Might try a weaker solution at first and build up to it........
Thanks again though
Rhubarb...Bhubarb...Rhubarb......

 

[VicS]

Re: OXALIC ACID

I tried to find some solubility data for oxalic acid but I don't seem to have any. I think the 4oz per pint (equal to 200g per litre) will probably be about saturated. In fact it would not surprise me if that's more than saturated at ambient temperatures. If it starts to crystallise out on cooling add a bit more water and make it more dilute second time round. For lightening wood The Woodworker's Pocket Book suggests only half that concentration.

I wouldn't mess about with more dilute solutions I would go for the "full monty". Try a small patch first, not because of any likely problems, but to see if it works and how long it takes. It would be gutting to paint it laboriously over the whole boat only to find it's ineffective!

Take care washing it away. It'll be classed as hazardous waste so a Boat yard and the relevant environmental agencies would be within their rights in stopping you just washing it onto the ground. Imagine what a fag it would be you had to collect it all up and take it to a licenced tip!

 

[boatmike]

Re: OXALIC ACID

Thanks again Vic. Spookily enough I have a very old copy of "Practical Woodworker" that gives details of using it in a furniture restoration project. That too suggests a lesser concentration so I think I will mix up small amounts to test at first keeping enough in reserve to go to full strength if I need to. As I only need the wallpaper paste for vertical surfaces I will do patch tests on the deck at half concentration first without the paste. If this works OK then fine but if it doesn't I will tip the rest in to get to 200g per litre before I put the paste in.
I will report the effects back to the forum in due course. Thanks again for your help

 

[pheran]

Re: OXALIC ACID

..............'I think the 4oz per pint (equal to 200g per litre) will probably be about saturated. In fact it would not surprise me if that's more than saturated at ambient temperatures'. <font color="blue"> </font>

I've used OA at a solution of 2oz/pint of warm water (warm to help it disolve) for years to clean my teak decks and it makes a wonderful job of them. Can't imagine you'd want anything stronger on nice shiney gelcoat. When washing off, use loads of water and be careful of run-off. Wont strip A/F but could mark boot-top etc.

 

[geoffatstanpit]

1. It's Oxalic Acid - (no "y"). That should help searches!

2. The solubility is about 1% at 15 C so there's no point in trying to get anything like 20%. A spoonful in a jamjar sounds about right!

3. Wallpaper paste isn't anything like as good as the stuff they put in Y10 for thickening. Has anyone any idea where to get their stuff?

Geoff

 

[Vara]

Guessing----- its probably a surfactant(detergent) thickened with salt(NaCL) to make it go gloopy.

 

[VicS]

Re: Oxalic Acid

Only 1% at 15C! What is your source for this infomation?
A Google search has found figures of 10g/ 100ml and 7g/ 100ml but the temperatures are not specified nor is it certain whether they are for the anhydrous material or the dihydrate. I assume that it is normally supplied as the latter. A figure of 7 for the anhydrous acid would correspond to figure of 10 for the dihydrate.

 

[fishermantwo]

Re: Oxalic Acid

I use Oxalic acid to clean the bait tanks on my fishing vessel. I buy it in liquid form in 20 litre containers. The stuff I buy is called "Metal Gleam". The same stuff can be bought from brick supply companies, oxalic acid is used to clean bricks.
I put about 2 cups of concentrate into 20 litres of warm water. Apply with a large sponge. Rinse off as soon as I can. It cleans in about 30 seconds. The same product is used by other fishermen here to clean up paint work before repainting. It softens the old paint work and removes the gloss slightly and makes the repainting better.

 

[tillergirl]

The usual 'boating' recipe is 25 grams to 500cc of water. You can make it a little stronger if you like. Dissolves best in warm water.