[TheForge] Chemical Questions ?

Wed Oct 16 08:59:01 2002

Dave,

There probably is no chlorine left to neutralize.  It's volatile and =
wouldn't hang around for long.  If you think otherwise, then dissolve a =
vitamin C tablet in a gallon of water and rinse the panel with that.  Any =
chlorine present will be converted to chloride.

Vinegar or dilute muriatic removes rust, but will rerust quickly.  =
Phosphoric acid will provide a protective coating that won't rust so =
quickly. =20

Commercial paint removers work well, especially if they contain dichloromet=
hane, AKA methylene chloride.  These will also degrease a surface.  =
However, dichloromethane is suspected of causing cancer, so treat it with =
great respect (outside).  Heat (flame) can remove paint nicely, but could =
warp thin metal.   Lye solution  (very corrosive to flesh and eyeballs!) =
can also do a number on paint. =20

So you could soak the panel in lye solution to remove the paint, then =
rinse it with water.  Next soak it in dilute muriatic acid to remove the =
rust, then rinse with water.  Finally, apply a phosphoric-acid containing =
material, like Naval Jelly, to remove the new rust and protect the =
surface.  This would keep the panel "wet", as opposed to changing =
solvents.

One problem I see is simply keeping a panel of that size wet.  If you =
might make a timber frame on a flat floor and line it with a heavy plastic =
drop cloth.  The acid treatment can be made up as a paste:  1 part vinegar =
to 1 part table salt to one part white flour.  Apply liberally and cover =
with thin plastic so it doesn't dry out.  I don't know whether you can do =
the same with a caustic treatment, and would be very careful.  Easy-off =
oven cleaner might do the job instead.  Or a paste-type commercial paint =
stripper.

Good luck.  Let us know how it works out.

Bruce
NJ

>>> "lama" <[email protected]> 10/16/02 01:32AM >>>
I have a couple of old (1930) and very delicate iron panels that need
refinishing.
The pieces are 10 feet tall, 3-1/2 feet wide and weigh 175 pounds each.
These panels were put on display in a room that has an indoor swimming =
pool.
The heavy concentration of chlorine in the atmosphere of the closed room
caused the iron panels to rust very rapidly and heavily.
I need to:
1. Chemically neutralize the chlorine.
2. Chemically remove the rust, old paint, etc.

Any advice greatly appreciated,
Dave Mudge

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