[TheForge] copper arch

Tue Apr 30 09:26:00 2002

Ralph,

Some of the other responses are not completely correct.
I suggest either using fresh, unused muriatic acid, diluted if you wish, =
or the effective equivalent:  distilled vinegar and table salt.  In either =
case you're using HCl to remove the acid-soluble copper salts from the =
surface.  HCl will NOT etch  metalic copper.  Ferric chloride will attack =
copper, so keep your HCl free of iron.

You can make a paste of equal parts vinegar, salt and wheat flower and =
apply it liberally to the outside of the tubing.  Wrap it with plastic to =
keep it moist, and reapply if necessary.  If the corrosion is heavy, this =
might not be practical, but it's easy to test on a short section.

The resulting copper will be "satin" fininshed and pinkish in color.  If =
the corrosion left a pitted surface, you'll have a pitted surface and will =
have to use a technique like sanding to get back to smooth.  If the =
surface is smooth, but satin, then burnishing might be a better choice =
than sanding, but not unless you can mechanize it.  Hand-burnishing fifty =
feet of tubing would not be fun.  Better to use 1500-grit sandpaper.

Bruce
NJ

>>> "Ralph Sproul" <[email protected]> 04/30/02 07:05AM >>>
        Any suggestions for cleaning up 50 feet of copper tubing for an =
arch
(15 year tarnish on it).

Ralph

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