Author Topic: coca-cola, tomatoe sauce and vinegar  (Read 3987 times)

richard

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coca-cola, tomatoe sauce and vinegar
« on: May 20, 2010, 09:31:30 AM »
hi again lets get onto more useful topics - well to me anyway ! old pennies in any of the above = shiney as new coins , accepted fact yes. well i had a very tarnished milldewed and verdi degree brass chassis plate on my '49 Bond and very stupidly imagined a similar effect . WRONG its gone a rather uncomfortable shade of pink ! you could be charitable and say bronze . question is what chemical reaction has taken place and what will reverse this ? ther must be someone intelligent out there ...................... or not ? Thanks for listening but this is cheaper than the therapy i have been getting , probably just as useless too ! by the way it was a serious question by the way ;D
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Chris Thomas

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Re: coca-cola, tomatoe sauce and vinegar
« Reply #1 on: May 20, 2010, 12:31:23 PM »
Dear Richard

I am no chemist but try some Brasso. It always works for me.

Chris Thomas

richard

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Re: coca-cola, tomatoe sauce and vinegar
« Reply #2 on: May 20, 2010, 06:25:02 PM »
tried it but its plated and wont shift - i dont really want to scrape and scratch it , thanks anywayl
outside of a dog a book is mans best friend. Inside of a dog it's too dark to read .Groucho Marx 1895-1977

Bob Purton

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Re: coca-cola, tomatoe sauce and vinegar
« Reply #3 on: May 20, 2010, 11:49:26 PM »
There is no cure for your chassis plate, brass is an alloy of copper and zinc, the zinc element has corroded away and you are looking at whats left, I come across this problem all the time with maritime antiques.

Rusty Chrome (Malcolm Parker)

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Re: coca-cola, tomatoe sauce and vinegar
« Reply #4 on: May 21, 2010, 12:24:55 AM »
Its a reaction called galvanic corrosion caused by the zinc in the brass being dissolved from the surface leaving the pink copper behind. Polishing with a slice of lemon dipped in salt crystals might be worth a try if brasso didn't touch it, or Solvol Autosol also has a bit more bite, but don't forget all these methods are ultimately damaging to the surface - wash the plate afterwards with soap & water. If all else fails you might have to resort to a trip to a re-plating shop.

The V&A has some good advice about cleaning metals if your aim is to preserve

http://www.vam.ac.uk/collections/metalwork/metalwork_features/caring_metals/cleaning_copper/index.html
Malcolm
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marcus

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Re: coca-cola, tomatoe sauce and vinegar
« Reply #5 on: May 21, 2010, 08:13:50 AM »
Jade oil (from axminster.co.uk) is a good coating for metals, looks less plasticky than lacquers, but does need occasional re-coating.
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Big Al

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Re: coca-cola, tomatoe sauce and vinegar
« Reply #6 on: May 21, 2010, 09:41:08 AM »
That is a bit of a tragady then. An embarrised chassis plate. I have used a bit of Coke to clean chassis plates before now but I have tended to leave them alone despite paint, corrosion and chunks being missing on occasion. Yes the alloy mix would make a difference. Pennies were good stuff. We have been warned
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richard

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Re: coca-cola, tomatoe sauce and vinegar
« Reply #7 on: May 21, 2010, 10:05:08 AM »
many thanks to all of the above . guess the lesson is think before you leap - i could have so easily tried it on the back first. that by the way is still beautifull and brassy -like a good barmaid  :D
outside of a dog a book is mans best friend. Inside of a dog it's too dark to read .Groucho Marx 1895-1977