Oxalic acid

zoidberg

zoidberg

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I understand this, in solution, is an effective oxidiser and good for cleaning stained GRP mouldings and even dingy teak capping. I also understand it is present in rhubarb, of which my wife yet again has a copious garden crop.

Would it be effective on stained GRP and dulled chromework if I rubbed the relevant parts with handfuls of rhubarb stalks...?
 
You may need something else to remove the stain from the, pink, rhubarb :). If your yacht is moulded from pink gelcoat I am sure it will work well (and I would not worry about the chrome :) .

Jonathan
 
zoidberg said:
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Would it be effective on stained GRP and dulled chromework if I rubbed the relevant parts with handfuls of rhubarb stalks...?
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By all means try it but have plenty of water at hand to way away the custard as it will likely be very messy. Perhaps, too, a risk of the wrath from your wife for not eating your dessert. ?
 
Neeves said:
You may need something else to remove the stain from the, pink, rhubarb :). If your yacht is moulded from pink gelcoat I am sure it will work well (and I would not worry about the chrome :) .
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It's mostly in the green leaves. There's little in the stems, which is just as well, as it's poisonous. After frantic rubbing of the gelcoat you'd have to be careful that you didn't mistake the resulting green leafy pile for spinach and eat it, because 8kg of the stuff will kill you, and that would be a shame.
 
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zoidberg said:
I understand this, in solution, is an effective oxidiser and good for cleaning stained GRP mouldings and even dingy teak capping. I also understand it is present in rhubarb, of which my wife yet again has a copious garden crop.

Would it be effective on stained GRP and dulled chromework if I rubbed the relevant parts with handfuls of rhubarb stalks...?
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At a concentration in the leaves of only 0.5%, you'd have to rub the relevant parts 200 times to get full effectiveness. It might take a while.
 
AngusMcDoon said:
At a concentration in the leaves of only 0.5%, you'd have to rub the relevant parts 200 times to get full effectiveness. It might take a while.
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I also remember the 0.5% figure from many decades ago. Temperature is also very important and the reaction rate falls off a cliff below 10 °C. It is pretty quick above 20 °C but 25-30 °C would be much better. Just a matter of lowering the hull into a large vat containing a few tonnes of pulverised rhubarb leaves in hot water and keeping it there for several hours. :D:D
 
Mistroma said:
I also remember the 0.5% figure from many decades ago. Temperature is also very important and the reaction rate falls off a cliff below 10 °C. It is pretty quick above 20 °C but 25-30 °C would be much better. Just a matter of lowering the hull into a large vat containing a few tonnes of pulverised rhubarb leaves in hot water and keeping it there for several hours. :D:D
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Would not work on its own. The boat would want to float on the hot water. Thus missing the topsides. You would have to fill the inside with custard to weigh it down, so the rhubarb reached the deck level.
Personally, I would use blancmange so you could have different flavours in each cabin.
 
I bought some oxalic acid in crystalline form a while ago. Dissolve in warm water to form a strong solution. I've removed rust stains successfully and it was very good at lightening discoloration on wood. You need to add some thickening agent to the solution when used on non horizontal surfaces to keep it in contact long enough to work. I used wallpaper paste.
 
ghostlymoron said:
I bought some oxalic acid in crystalline form a while ago. Dissolve in warm water to form a strong solution. I've removed rust stains successfully and it was very good at lightening discoloration on wood. You need to add some thickening agent to the solution when used on non horizontal surfaces to keep it in contact long enough to work. I used wallpaper paste.
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I gave some to a club member to use on the committe boat, along with the wallpaper paste. He did not tell me that he was going home & had left it on the topsides of boat. The paste dried & it took ages to scrape the stuff off. So whatever you do, get it off before the paste dries.
 
ghostlymoron said:
I bought some oxalic acid in crystalline form a while ago. Dissolve in warm water to form a strong solution. I've removed rust stains successfully and it was very good at lightening discoloration on wood. You need to add some thickening agent to the solution when used on non horizontal surfaces to keep it in contact long enough to work. I used wallpaper paste.
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I use about 50% washing up liquid. The cheapest stuff in Aldi usually. It is very effective on vertical and horizontal surfaces. Wash off with a soft sponge or long handled brush and then hose with 7 clean water.
 
Mistroma said:
I also remember the 0.5% figure from many decades ago. Temperature is also very important and the reaction rate falls off a cliff below 10 °C. It is pretty quick above 20 °C but 25-30 °C would be much better. Just a matter of lowering the hull into a large vat containing a few tonnes of pulverised rhubarb leaves in hot water and keeping it there for several hours. :D:D
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You make it sound easy ?
 
pandos said:
I think you will find that those are clean spots not stains...

The advantage of using washing up liquid is that you can wash it about with a sponge more water and it has the effect of fading any unwanted cleanliness..
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No it seemed to bleach the 2 pack paint on my hull with lines from the drips off the acid.
 
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