RUMCars Forum

General Category => Unusual Microcar Discussion => Topic started by: richard on May 20, 2010, 09:31:30 AM

Title: coca-cola, tomatoe sauce and vinegar
Post by: richard 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
Title: Re: coca-cola, tomatoe sauce and vinegar
Post by: Chris Thomas 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
Title: Re: coca-cola, tomatoe sauce and vinegar
Post by: richard 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
Title: Re: coca-cola, tomatoe sauce and vinegar
Post by: Bob Purton 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.
Title: Re: coca-cola, tomatoe sauce and vinegar
Post by: Rusty Chrome (Malcolm Parker) 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 (http://www.vam.ac.uk/collections/metalwork/metalwork_features/caring_metals/cleaning_copper/index.html)
Title: Re: coca-cola, tomatoe sauce and vinegar
Post by: marcus 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.
Title: Re: coca-cola, tomatoe sauce and vinegar
Post by: Big Al 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
Title: Re: coca-cola, tomatoe sauce and vinegar
Post by: richard 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